Foundation Drainage
Neutrality remake campaign: from-scratch field derivation per authoring cheatsheet; project parameters and derived dispositions
Showing changes from Rev 4
to Rev 5
in Foundation Drainage.
−---
−title: Foundation Drainage
−category: Building Envelope
−toc_depth: 3
−description: >
− When to use: Perimeter and sub-slab drainage protecting below-grade structures for commercial, institutional, and residential buildings. Covers foundation drain pipe (perforated PE corrugated, HDPE smooth-wall, and PVC profile wall), prepared open-graded aggregate envelopes, nonwoven filter fabric, prefabricated dimpled drainage composites on foundation walls, sub-slab and crawl-space drainage layers, cleanouts, sumps with simplex or duplex pumps for lift conditions, and gravity discharge to daylight, a dry well, or a storm drainage system. Coordinates with below-grade waterproofing to relieve hydrostatic head before water reaches the membrane.
− Not intended for: Below-grade waterproofing or dampproofing membranes (see [[sync/below-grade-waterproofing]]); site storm drainage piping, inlets, and catch basins outside the perimeter drain (see [[sync/storm-drainage]]); subgrade preparation, structural backfill, and compaction (see [[sync/earthwork]]); aggregate base course beneath paving and slabs serving a structural rather than drainage function (see [[sync/aggregate-base-course]]); subsoil drainage of agricultural fields, athletic fields, or landscaped planters; pavement edge drains (covered by ASTM D7001 and not within this scope); interior dewatering during construction.
−---
−
−# Scope {toc}
−
−## This standard covers the design basis, materials, installation, and field testing of foundation drainage systems serving below-grade structures. {note}
−## The system encompasses the perimeter footing drain, the prepared open-graded aggregate envelope around that drain, the nonwoven geotextile filter fabric separating the envelope from adjacent soil, prefabricated dimpled drainage composites installed against waterproofed foundation walls, the sub-slab granular drainage layer beneath slabs on grade in hydrostatic conditions, cleanouts and observation ports, sump pits with simplex or duplex pumps where gravity discharge is not feasible, and the discharge piping to its approved outlet — daylight, a dry well, or a storm drainage system. {note}
−
−## Foundation drainage and below-grade waterproofing are complementary, not interchangeable. {note}
−## Waterproofing keeps water out of the structure; drainage relieves hydrostatic head before water reaches the waterproofing. {note}
−## An assembly that omits drainage and relies on the waterproofing membrane alone forces the membrane to resist standing head over its full service life, which is a service condition that drives down membrane reliability and shortens the useful life of the assembly. {note}
−## Conversely, an assembly that omits or undersizes the waterproofing and relies on drainage alone will fail under any condition that overwhelms the drainage capacity (clogged outlet, heavy storm event, pump failure, frozen daylight discharge, rising groundwater table). {note}
−## The correct design approach for any below-grade assembly subject to hydrostatic or intermittently hydrostatic conditions is a complete system: waterproofing plus drainage plus a redundant interior collection or sump capacity. {note}
−## Coordinate with [[sync/below-grade-waterproofing]] for the membrane scope; this standard governs only the drainage scope. {note}
−
−## The Engineer of Record shall establish the design groundwater elevation and the expected seasonal high water table elevation from a site-specific geotechnical investigation.
−
−## The drainage system shall be designed for the seasonal high water condition, not for the average groundwater elevation.
−
−## A perimeter drain sized for average conditions will be overwhelmed during the spring thaw or extended rain events that produce the design loading the system exists to manage. {note}
−
−## Coordinate site grading, backfill, and the structural compaction zone with [[sync/earthwork]]; coordinate the drainage envelope aggregate gradation with [[sync/aggregate-base-course]]; coordinate the downstream piping and outlet point with [[sync/storm-drainage]].
−
−# Referenced Standards {toc}
−
−## Materials, testing, and installation shall comply with the current edition of the following standards.
−## Where contract documents or referenced standards conflict, the more stringent requirement governs unless the Engineer of Record directs otherwise in writing. {note}
−
−| Standard | Title |
−|----------|-------|
−| IBC Section 1805.4 | Foundation Drainage (International Building Code) |
−| IRC Section R405 | Foundation Drainage (International Residential Code) |
−| ASTM F405 | Standard Specification for Corrugated Polyethylene (PE) Pipe and Fittings (3 in. through 6 in.) |
−| ASTM F667 | Standard Specification for 3 through 24 in. Corrugated Polyethylene Pipe and Fittings |
−| ASTM F758 | Standard Specification for Smooth-Wall Poly(Vinyl Chloride) (PVC) Plastic Underdrain Systems for Highway, Airport, and Similar Drainage |
−| ASTM D3034 | Standard Specification for Type PSM Poly(Vinyl Chloride) (PVC) Sewer Pipe and Fittings |
−| ASTM F949 | Standard Specification for Poly(Vinyl Chloride) (PVC) Corrugated Sewer Pipe with a Smooth Interior and Fittings |
−| AASHTO M252 | Standard Specification for Corrugated Polyethylene Drainage Pipe |
−| AASHTO M294 | Standard Specification for Corrugated Polyethylene Pipe, 12 in. to 60 in. Diameter |
−| ASTM D7001 | Standard Specification for Geocomposites for Pavement Edge Drains and Other High-Flow Applications |
−| ASTM D6707 | Standard Specification for Circular-Knit Geotextile for Use in Subsurface Drainage Applications |
−| ASTM D7140 | Standard Test Method to Measure Resistance of Geosynthetic Drainage Composites to Compressive Creep |
−| ASTM D4716 | Standard Test Method for Determining the (In-Plane) Flow Rate per Unit Width and Hydraulic Transmissivity of a Geosynthetic Using a Constant Head |
−| ASTM D5101 | Standard Test Method for Measuring the Filtration Compatibility of Soil-Geotextile Systems (Gradient Ratio) |
−| ASTM D4491 | Standard Test Methods for Water Permeability of Geotextiles by Permittivity |
−| ASTM D4751 | Standard Test Methods for Determining Apparent Opening Size of a Geotextile |
−| ASTM D4632 | Standard Test Method for Grab Breaking Load and Elongation of Geotextiles |
−| ASTM D4833 | Standard Test Method for Index Puncture Resistance of Geomembranes and Related Products |
−| ASTM D698 | Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Standard Effort |
−
−# Submittals {toc}
−
−## Action Submittals {toc}
−
−### The Contractor shall submit the following for the Engineer's review and approval prior to procurement or installation of any foundation drainage materials.
−### No portion of the drainage installation shall proceed until the corresponding submittals have been reviewed and returned.
−
−- Manufacturer's product data sheets for drain pipe, fittings, cleanouts, drainage composite, geotextile filter fabric, and sump pump assemblies, including published flow capacity, perforation pattern, joint type, and chemical resistance
−- Aggregate gradation report from the supplier confirming compliance with the specified open-graded gradation, dated within 6 months of delivery
−- Geotextile filter fabric test reports demonstrating compliance with the specified AOS (ASTM D4751), permittivity (ASTM D4491), grab tensile (ASTM D4632), and puncture resistance (ASTM D4833)
−- Drainage composite test reports demonstrating in-plane transmissivity at the design overburden pressure (ASTM D4716) and compressive creep resistance (ASTM D7140)
−- Filtration compatibility evaluation per ASTM D5101 (gradient ratio) where in-situ soils are fine-grained, dispersive, or otherwise of questionable compatibility with the proposed filter fabric
−- Sump pump cut sheets including curve, motor data, controls, float and alarm system, and basin or pit dimensions
−- Shop drawings showing perimeter drain alignment, invert elevations at corners and cleanouts, slope, cleanout locations, sump pit location, discharge piping routing, and daylight or connection point to the storm drainage system
−- Installer qualifications
−
−```datasheet
−label: Action Submittals Required
−type: checkbox
−options:
− - "Product data for drain pipe, fittings, cleanouts"
− - "Aggregate gradation report (dated within 6 months)"
− - "Geotextile test reports — AOS, permittivity, tensile, puncture"
− - "Drainage composite test reports — transmissivity and creep"
− - "Filtration compatibility evaluation per ASTM D5101"
− - "Sump pump cut sheets and control diagram"
− - "Shop drawings — alignments, inverts, cleanouts, discharge"
− - "Installer qualifications"
−default: "Product data for drain pipe, fittings, cleanouts"
−```
−
−## Closeout Submittals {toc}
−
−### The Contractor shall provide the following at substantial completion before the foundation drainage system is accepted.
−
−- Record drawings showing as-installed perimeter drain alignment, invert elevations at corners and cleanouts, cleanout locations, sump pit location, and discharge point
−- Functional flow test report signed by the testing technician
−- Sump pump start-up report, including pump down test, alarm verification, and float setpoint documentation
−- Manufacturer's written warranty for sump pumps, controls, and check valves running to the Owner
−- Operation and maintenance manual covering sump pump operation, cleanout access locations, recommended inspection intervals, and discharge outlet inspection procedure
−
−```datasheet
−label: Closeout Submittals Required
−type: checkbox
−options:
− - "Record drawings — as-installed alignment, inverts, cleanouts, discharge"
− - "Functional flow test report signed by testing technician"
− - "Sump pump start-up report — pump down test, alarm, float setpoints"
− - "Manufacturer's written warranty for sump pumps, controls, check valves"
− - "Operation and maintenance manual"
−default:
− - "Record drawings — as-installed alignment, inverts, cleanouts, discharge"
− - "Functional flow test report signed by testing technician"
− - "Sump pump start-up report — pump down test, alarm, float setpoints"
− - "Manufacturer's written warranty for sump pumps, controls, check valves"
− - "Operation and maintenance manual"
−```
−
−# Quality Assurance {toc}
−
−## Installer Qualifications {toc}
−
−### Foundation drainage shall be installed by a Contractor experienced in below-grade drainage work who can demonstrate completion of similar projects of comparable scope and groundwater conditions.
−
−### The Contractor responsible for sump pump and electrical control installation shall be a licensed plumbing and electrical subcontractor where required by the Authority Having Jurisdiction.
−
−## Pre-Installation Conference {toc}
−
−### A pre-installation conference shall be held on-site before drainage installation begins.
−
−### The conference shall include the Owner's Representative or Engineer, the General Contractor, the excavation and earthwork subcontractor, the waterproofing subcontractor, and the drainage installer.
−
−### Conference topics shall include sequencing between excavation, waterproofing, drainage envelope placement, and backfill; coordination of the perimeter drain invert with the bottom-of-footing elevation; protection of the waterproofing membrane during drainage installation; cleanout locations; sump and discharge tie-in; and the functional flow test plan.
−
−### Minutes shall be recorded and distributed.
−
−### The pre-installation conference is the most cost-effective quality step in foundation drainage; the most common failure modes — backfall, fines migration into the envelope, an envelope that ends short of the perimeter without daylight, and a sump never wired to its alarm — are sequencing and coordination errors that surface at this conference if it is held. {note}
−
−## Regulatory Inspection {toc}
−
−### The installed foundation drainage system, including the perimeter drain, aggregate envelope, and filter fabric, shall be available for inspection by the Authority Having Jurisdiction before being covered by backfill.
−
−### The Contractor shall coordinate inspection timing so that the inspector can verify pipe slope, invert elevation, envelope dimensions, fabric coverage, and cleanout location before any concealing work proceeds.
−
−# Design Basis {toc}
−
−## Hydrostatic Condition {toc}
−
−### The design groundwater condition established for the [[sync/below-grade-waterproofing]] scope governs the drainage system design. {note}
−
−### The drainage system shall be sized for the seasonal high water table elevation reported in the geotechnical investigation, not the average elevation.
−
−### Design Groundwater Condition Datasheet {toc}
−
−```datasheet
−label: Design Groundwater Condition (coordinate with below-grade waterproofing)
−type: radio
−options:
− - "Non-hydrostatic — groundwater table is at least 6 ft below lowest slab; perimeter drain is a code-required protection against perched water and roof/grade runoff"
− - "Intermittently hydrostatic — seasonal high water table reaches below-grade assembly; perimeter drain is the primary head-relief system"
− - "Continuously hydrostatic — groundwater table is at or above the lowest slab elevation; full drainage envelope plus sub-slab drainage layer required"
−drawing_ref: true
−default: "Intermittently hydrostatic — seasonal high water table reaches below-grade assembly; perimeter drain is the primary head-relief system"
−```
−
−## Discharge Method {toc}
−
−### The single most important decision in foundation drainage system layout — after the decision to provide drainage at all — is the discharge method. {note}
−### IRC Section R405.1 and IBC Section 1805.4 require the perimeter drain to discharge by gravity or mechanical means into an approved drainage system. {note}
−### The three viable discharge methods are gravity discharge to daylight, gravity discharge to a storm sewer or storm drainage system, and pumped discharge from a sump pit. {note}
−### Local jurisdiction rules vary on which methods are permitted and on whether sump discharge to a sanitary sewer is allowed (it is generally prohibited). {note}
−
−### Gravity discharge is always preferred over pumped discharge where the site permits, because a gravity outlet has no moving parts, no power dependency, and no service life limit, whereas a pumped outlet depends on a sump pump of finite service life (typically 5 to 10 years for a residential simplex pump and longer for commercial duplex units), on continuous electrical service, and on the alarm system being maintained. {note}
−
−### Pump failure is one of the most common causes of below-grade water entry; pump backup (battery, generator, or duplex) is therefore mandatory in any application where flooding from pump failure would result in significant property loss. {note}
−
−### Discharge Method Datasheet {toc}
−
−```datasheet
−label: Foundation Drainage Discharge Method
−type: radio
−options:
− - "Gravity discharge to daylight — perimeter drain outlets to a daylit grade outside the foundation footprint, freeze-protected"
− - "Gravity discharge to storm drainage system — perimeter drain ties into project storm sewer or municipal storm sewer at an approved connection"
− - "Pumped discharge from sump pit — perimeter drain collects to a sump pit, pumped through a discharge line to daylight or storm drainage"
− - "Combination — gravity-flow segment to a low-point sump pit at the foundation, pumped from the pit to the discharge destination"
−drawing_ref: true
−default: "Gravity discharge to storm drainage system — perimeter drain ties into project storm sewer or municipal storm sewer at an approved connection"
−```
−
−### Sump pump discharge to a sanitary sewer is prohibited in nearly all jurisdictions and shall not be specified or installed.
−
−### Discharge shall be made only to an approved storm drainage system, to daylight, or to a dry well sized and permitted by the local Authority Having Jurisdiction.
−
−### The Contractor shall verify the permitted discharge method with the local jurisdiction before procurement of sump or pump materials.
−
−## Freeze Protection of Daylight Discharge {toc}
−
−### Where the discharge is to daylight, the outlet point shall be located below the local frost depth or protected from freezing.
−
−### An outlet that freezes shut during winter conditions converts the perimeter drain into a sealed system holding water against the foundation — the exact condition the drain exists to prevent. {note}
−
−### Daylight outlets shall include a rodent and debris screen and shall be visibly accessible for routine inspection.
−
−### Daylight Outlet Freeze Protection Datasheet {toc}
−
−```datasheet
−label: Daylight Outlet — Freeze Protection
−type: radio
−options:
− - "Outlet located below local frost depth, with insulated and freeze-protected riser"
− - "Outlet at daylit grade, freeze-protected by heat tape on the riser"
− - "Outlet at daylit grade, climate confirms no winter freeze (warm climate zones only)"
− - "Not applicable — discharge is to a buried storm system or pumped"
−drawing_ref: true
−default: "Outlet located below local frost depth, with insulated and freeze-protected riser"
−```
−
−# Perimeter Drain Pipe {toc}
−
−## The perimeter drain pipe shall be a perforated thermoplastic pipe of sufficient diameter and stiffness to carry the design flow and to resist construction and backfill loads.
−
−## Three thermoplastic pipe types are accepted by this standard for foundation drainage service: corrugated polyethylene (PE) pipe, smooth-wall high-density polyethylene (HDPE) pipe, and smooth-wall poly(vinyl chloride) (PVC) pipe.
−
−## Perimeter Drain Pipe Type Datasheet {toc}
−
−```datasheet
−label: Perimeter Drain Pipe Type
−type: radio
−options:
− - "Perforated corrugated polyethylene (PE) pipe conforming to ASTM F405 / AASHTO M252 — typical for residential and light commercial foundation drainage"
− - "Perforated smooth-wall HDPE pipe — improved flow characteristics and lower hydraulic loss, preferred for long runs or low slope conditions"
− - "Perforated smooth-wall PVC pipe conforming to ASTM F758 (Type PS 28 or PS 46) — preferred where root intrusion, abrasion, or long service life is a priority"
− - "Perforated PVC sewer pipe conforming to ASTM D3034 SDR 35 — acceptable where coordinated with downstream storm sewer of the same material and joint system"
−drawing_ref: true
−default: "Perforated corrugated polyethylene (PE) pipe conforming to ASTM F405 / AASHTO M252 — typical for residential and light commercial foundation drainage"
−```
−
−## The minimum nominal pipe diameter for foundation drainage shall be 4 in. for residential and light commercial applications.
−
−## Larger diameters shall be used where the design flow, the total run length, or the available pipe slope requires additional hydraulic capacity.
−
−## The pipe diameter shall be sized by the Engineer.
−
−## Specifying the minimum 4-in. diameter on a long, low-slope run with multiple inlet points is a hydraulic shortcut that produces a hydraulically inadequate system. {note}
−
−## Pipe Diameter and Slope Datasheets {toc}
−
−```datasheet
−label: Perimeter Drain — Minimum Pipe Diameter
−type: select
−unit: in
−options:
− - "4 in. (minimum, typical residential and light commercial)"
− - "6 in. (long runs, low slope, or multiple inlet points)"
− - "8 in. (commercial buildings with high design flow or shared building loop)"
−drawing_ref: true
−default: "4 in. (minimum, typical residential and light commercial)"
−```
−
−```datasheet
−label: Perimeter Drain — Minimum Pipe Slope
−type: select
−unit: percent
−options:
− - "0.5 percent (1/16 in. per ft, minimum for smooth-wall pipe with verified hydraulic capacity)"
− - "1.0 percent (1/8 in. per ft, recommended minimum for smooth-wall pipe)"
− - "2.0 percent (1/4 in. per ft, recommended minimum for corrugated PE pipe to compensate for higher friction loss)"
−drawing_ref: true
−default: "1.0 percent (1/8 in. per ft, recommended minimum for smooth-wall pipe)"
−```
−
−## Pipe perforations shall be sized and patterned to admit water from the surrounding aggregate envelope without admitting the envelope aggregate itself.
−
−## Two perforation patterns are commonly available: small circular perforations (typically 3/8 in. diameter) arrayed in rows, and longitudinal slots; where a fine-grained envelope or marginal-gradation backfill is in use, slot perforations sized to the envelope gradation reduce the rate of fines intrusion compared to large circular perforations. {note}
−
−## The pipe shall be installed with the perforations oriented downward unless the manufacturer's installation instructions specifically direct otherwise.
−
−## Downward orientation allows water to enter throughout the entire surrounding envelope and keeps the upper pipe surface available as a freeboard reservoir during peak flow. {note}
−
−## Perforation Pattern and Orientation Datasheets {toc}
−
−```datasheet
−label: Drain Pipe Perforation Pattern
−type: radio
−options:
− - "Circular perforations, 3/8-in. diameter, in rows (typical for PE corrugated pipe)"
− - "Longitudinal slots, sized for envelope gradation (preferred where envelope gradation is fine or marginal)"
− - "Per manufacturer's standard pattern — confirm slot or hole size is compatible with envelope and filter fabric AOS"
−default: "Circular perforations, 3/8-in. diameter, in rows (typical for PE corrugated pipe)"
−```
−
−```datasheet
−label: Drain Pipe Perforation Orientation
−type: radio
−options:
− - "Perforations down (preferred — uses full pipe diameter as flow capacity reserve)"
− - "Perforations up (only where manufacturer's installation instructions specifically require)"
− - "Per manufacturer's installation instructions"
−default: "Perforations down (preferred — uses full pipe diameter as flow capacity reserve)"
−```
−
−## A factory-installed geotextile sock around corrugated PE pipe is acceptable as a fines-exclusion device in clean granular soils but shall not be substituted for the perimeter aggregate envelope and the field-installed filter fabric in fine-grained or marginal soils.
−
−## A sock alone in silty or clayey backfill is a known failure mode; the sock clogs from the outside in, the perimeter drain loses inflow capacity, and the system fails silently. {note}
−
−# Drainage Aggregate Envelope {toc}
−
−## The drainage aggregate envelope around the perimeter drain pipe shall be a clean, washed, open-graded crushed stone of sufficient void space to convey water freely to the pipe and of sufficient particle size to be retained by the pipe perforations without entering the pipe.
−
−## The two most common gradations accepted by this standard are AASHTO #57 (nominal 1 in. top size) and AASHTO #67 (nominal 3/4 in. top size); both are washed open-graded materials available throughout the US construction market. {note}
−
−## Drainage Envelope Aggregate Gradation Datasheet {toc}
−
−```datasheet
−label: Drainage Envelope Aggregate Gradation
−type: radio
−options:
− - "AASHTO #57 — nominal 1-in. top size, washed, open-graded (typical)"
− - "AASHTO #67 — nominal 3/4-in. top size, washed, open-graded (preferred where #57 is locally unavailable or where pipe perforations are larger than 3/8 in.)"
− - "Project-specific gradation per geotechnical engineer — gradation must be open-graded and compatible with pipe perforation size"
−default: "AASHTO #57 — nominal 1-in. top size, washed, open-graded (typical)"
−```
−
−## The aggregate shall be washed at the source to remove fines (material passing the No. 200 sieve).
−
−## Unwashed pit-run stone with significant fines content shall not be used in the drainage envelope, even where the parent gradation envelope is correct.
−
−## The aggregate gradation report submitted before delivery shall confirm both the size gradation and the percent passing the No. 200 sieve (which should be less than 2 percent).
−
−## Envelope Dimension Datasheets {toc}
−
−```datasheet
−label: Drainage Envelope — Minimum Envelope Dimension (around pipe)
−type: select
−unit: in
−options:
− - "6 in. on all sides (IRC R405 minimum)"
− - "8 in. on all sides (recommended for hydrostatic conditions)"
− - "12 in. on all sides (recommended for high-flow conditions or fine-grained native soil)"
−drawing_ref: true
−default: "6 in. on all sides (IRC R405 minimum)"
−```
−
−```datasheet
−label: Drainage Envelope — Extension Beyond Footing Face
−type: select
−unit: in
−options:
− - "12 in. beyond outside edge of footing (IRC R405 minimum)"
− - "18 in. beyond outside edge of footing (recommended for hydrostatic conditions)"
−drawing_ref: true
−default: "12 in. beyond outside edge of footing (IRC R405 minimum)"
−```
−
−# Filter Fabric {toc}
−
−## A nonwoven needle-punched geotextile filter fabric shall be installed around the drainage aggregate envelope, separating it from the native soil or backfill on all sides.
−
−## The fabric shall pass water freely from the soil into the envelope while retaining soil fines that would migrate into and clog the envelope under groundwater flow.
−
−## The fabric is the long-term protection that determines whether the drainage envelope retains its design void space through the service life of the building; an aggregate envelope without filter fabric, or with the wrong filter fabric, is a one-season drainage system. {note}
−
−## Filter Fabric Type Datasheet {toc}
−
−```datasheet
−label: Filter Fabric Type
−type: radio
−options:
− - "Nonwoven needle-punched geotextile, minimum 8 oz/sq yd"
− - "Nonwoven needle-punched geotextile, minimum 6 oz/sq yd (acceptable where mechanical protection is provided by adjacent assembly)"
− - "Circular-knit geotextile conforming to ASTM D6707 (sock applications around pipe only — not for envelope wrap)"
−default: "Nonwoven needle-punched geotextile, minimum 8 oz/sq yd"
−```
−
−## The fabric shall meet the following performance properties, with test reports submitted before installation.
−
−## Filter Fabric Performance Property Datasheets {toc}
−
−```datasheet
−label: Filter Fabric — Maximum Apparent Opening Size (AOS) per ASTM D4751
−type: select
−unit: mm
−options:
− - "0.43 mm maximum (#40 sieve equivalent) — coarse to medium granular soils"
− - "0.25 mm maximum (#60 sieve equivalent) — fine sand and silty soils"
− - "0.18 mm maximum (#80 sieve equivalent) — fine-grained or silty soils"
−default: "0.25 mm maximum (#60 sieve equivalent) — fine sand and silty soils"
−```
−
−```datasheet
−label: Filter Fabric — Minimum Permittivity per ASTM D4491
−type: select
−unit: 1/sec
−options:
− - "0.3 sec⁻¹ minimum (low-flow conditions, fine-grained soils)"
− - "0.5 sec⁻¹ minimum (typical foundation drainage applications)"
− - "1.0 sec⁻¹ minimum (high-flow conditions or where rapid drawdown is required)"
−default: "0.5 sec⁻¹ minimum (typical foundation drainage applications)"
−```
−
−```datasheet
−label: Filter Fabric — Minimum Grab Tensile per ASTM D4632
−type: select
−unit: lb
−options:
− - "120 lb minimum (light duty)"
− - "157 lb minimum (typical foundation drainage)"
− - "200 lb minimum (heavy duty, mechanical protection role)"
−default: "157 lb minimum (typical foundation drainage)"
−```
−
−```datasheet
−label: Filter Fabric — Minimum Puncture Resistance per ASTM D4833
−type: select
−unit: lb
−options:
− - "50 lb minimum"
− - "75 lb minimum"
− - "100 lb minimum"
−default: "75 lb minimum"
−```
−
−## Where the in-situ soil is fine-grained, dispersive, internally unstable (gap-graded), or otherwise of questionable filter compatibility with the proposed AOS, a soil-geotextile gradient ratio evaluation per ASTM D5101 shall be performed before fabric selection is finalized.
−
−## The gradient ratio test identifies clogging potential and piping potential that are not predictable from AOS and permittivity alone. {note}
−
−## A gradient ratio greater than 3 indicates clogging risk and the fabric specification shall be revised before installation.
−
−## The geotechnical engineer is responsible for identifying soils that require this evaluation, and the Contractor shall not waive this requirement on the basis of a "standard" fabric specification.
−
−## Gradient Ratio Evaluation Datasheet {toc}
−
−```datasheet
−label: Soil-Geotextile Gradient Ratio Evaluation per ASTM D5101 Required
−type: radio
−options:
− - "Yes — fine-grained, dispersive, or marginal-gradation native soil per geotechnical engineer"
− - "No — clean granular native soil with confirmed filter compatibility"
−default: "No — clean granular native soil with confirmed filter compatibility"
−```
−
−# Drainage Composite (Walls) {toc}
−
−## A prefabricated drainage composite, also termed a drainage board or geocomposite drainage panel, shall be installed against the waterproofed face of below-grade walls where the design groundwater condition is hydrostatic or intermittently hydrostatic.
−
−## The composite consists of a dimpled or molded HDPE core that provides an open flow channel against the wall, faced on the soil side by a nonwoven geotextile filter fabric that retains backfill fines, and serves three functions: a high-transmissivity vertical drainage path conveying groundwater downward to the perimeter drain, relief of hydrostatic pressure against the waterproofing membrane, and protection of the membrane from mechanical damage during backfill. {note}
−
−## Drainage Composite Requirement Datasheet {toc}
−
−```datasheet
−label: Drainage Composite — Required on Waterproofed Walls
−type: radio
−options:
− - "Yes — drainage composite required on all waterproofed walls in hydrostatic or intermittently hydrostatic conditions"
− - "Yes — drainage composite required on all waterproofed walls regardless of groundwater condition (recommended)"
− - "No — free-draining granular backfill (less than 5 percent passing No. 200 sieve) of sufficient width substituted for drainage composite (acceptable only in confirmed non-hydrostatic conditions)"
−drawing_ref: true
−default: "Yes — drainage composite required on all waterproofed walls in hydrostatic or intermittently hydrostatic conditions"
−```
−
−## Drainage Composite Core and Transmissivity Datasheets {toc}
−
−```datasheet
−label: Drainage Composite — Minimum Core Thickness
−type: select
−unit: in
−options:
− - "3/8 in. (minimum for residential and light commercial)"
− - "1/2 in. (typical commercial)"
− - "5/8 in."
− - "1 in. (high-flow conditions, deep walls, or high overburden pressure)"
−default: "1/2 in. (typical commercial)"
−```
−
−```datasheet
−label: Drainage Composite — Minimum In-Plane Transmissivity per ASTM D4716, at design overburden
−type: select
−unit: gal/min/ft
−options:
− - "5 gpm/ft minimum"
− - "10 gpm/ft minimum"
− - "15 gpm/ft minimum (high-flow conditions, deep walls)"
−default: "10 gpm/ft minimum"
−```
−
−## Compressive creep resistance per ASTM D7140 shall be considered for deep walls where soil overburden produces sustained pressure on the composite core.
−
−## A core that loses thickness under sustained load loses the void space that provides its drainage capacity, and a single transmissivity report at low pressure is not a sufficient design basis for deep applications. {note}
−
−## The drainage composite face filter fabric shall meet the same performance properties specified in the Filter Fabric section above.
−
−## Compatibility of the composite manufacturer's factory-laminated fabric with the in-situ backfill soil shall be confirmed before specification.
−
−## The factory fabric is fixed when the composite is ordered and cannot be field-substituted. {note}
−
−## The composite shall be installed with the dimpled core against the wall and the fabric face outward (against the soil).
−
−## The bottom edge of the composite shall terminate at or extend slightly below the top of the perimeter drain aggregate envelope so that water collected in the composite is conveyed directly into the envelope, not deposited at the soil-envelope interface where fabric clogging can occur.
−
−## Drainage Composite Bottom Termination Datasheet {toc}
−
−```datasheet
−label: Drainage Composite — Bottom Termination
−type: radio
−options:
− - "Composite bottom edge terminates within the perimeter drain aggregate envelope, behind the envelope filter fabric wrap"
− - "Composite bottom edge terminates 2 in. above the top of the aggregate envelope (alternative — relies on wall-face flow to transition into envelope)"
−drawing_ref: true
−default: "Composite bottom edge terminates within the perimeter drain aggregate envelope, behind the envelope filter fabric wrap"
−```
−
−# Sump Pit and Pump Assembly {toc}
−
−## Where gravity discharge is not feasible — typically because no point on the perimeter drain is high enough above an available outlet to maintain positive slope — collected water shall be conveyed to a sump pit and pumped through a discharge line to the discharge destination.
−
−## The sump pit shall be sized to receive the design flow at peak conditions and to provide sufficient working volume between pump-on and pump-off setpoints to limit pump cycling.
−
−## A pump that cycles excessively due to an undersized pit fails prematurely. {note}
−
−## Minimum pit interior diameter for residential applications is 18 in., and commercial applications shall be sized by the Engineer to the design flow and the pump curve.
−
−## Sump Pit Diameter Datasheet {toc}
−
−```datasheet
−label: Sump Pit — Minimum Interior Diameter
−type: select
−unit: in
−options:
− - "18 in. (residential simplex)"
− - "24 in. (light commercial simplex)"
− - "30 in. (commercial duplex)"
− - "36 in. or larger — sized to design flow, pump curve, and minimum cycle time"
−drawing_ref: true
−default: "18 in. (residential simplex)"
−```
−
−## Sump Pump Configuration Datasheet {toc}
−
−```datasheet
−label: Sump Pump — Configuration
−type: radio
−options:
− - "Simplex (single pump) — acceptable for residential and where a flooded basement from pump failure would not result in significant property loss"
− - "Duplex (two pumps with alternating duty) — required for commercial, institutional, and any finished basement application"
− - "Simplex primary with battery-backup secondary pump — acceptable residential alternative to duplex, providing backup against pump or power failure"
−default: "Duplex (two pumps with alternating duty) — required for commercial, institutional, and any finished basement application"
−```
−
−## A pump that does not have backup against its own failure or against utility power failure is a pump that has not been protected against its two most common failure modes. {note}
−
−## Battery backup, generator backup, or duplex configuration shall be provided for any sump serving a finished or occupied below-grade space.
−
−## Sump Pump Backup and Alarm Datasheets {toc}
−
−```datasheet
−label: Sump Pump — Backup Against Power Failure
−type: radio
−options:
− - "Battery-backup secondary pump (acceptable residential)"
− - "Building emergency generator (commercial and institutional)"
− - "Duplex pumps with shared backup power supply"
− - "None — non-critical use, occasional groundwater inflow only"
−default: "Battery-backup secondary pump (acceptable residential)"
−```
−
−```datasheet
−label: Sump Pump — High-Water Alarm Required
−type: radio
−options:
− - "Yes — local audible alarm with visible indicator at sump"
− - "Yes — local audible alarm plus remote notification to building management system or to a monitored alarm service"
− - "No — non-critical use only"
−default: "Yes — local audible alarm with visible indicator at sump"
−```
−
−## A high-water alarm float independent of the pump on/off floats shall be provided in every sump pit so that a pump failure is detected before water level reaches a flooding elevation.
−
−## The alarm shall be audible at the sump and shall, for commercial and institutional buildings, report to the building management system or to a monitored alarm service.
−
−## The pump discharge piping shall include a check valve to prevent backflow of discharged water into the pit when the pump cycles off, and a union or other dismantling connection to permit pump removal for service without cutting the discharge piping.
−
−## The check valve shall be installed in a horizontal or near-vertical orientation per manufacturer instructions and shall be accessible for service.
−
−## Sump Discharge Check Valve Datasheet {toc}
−
−```datasheet
−label: Sump Discharge Piping — Check Valve
−type: radio
−options:
− - "Swing check valve, full-port, accessible for service"
− - "Spring-loaded silent check valve (preferred where pump cycling produces water hammer)"
−default: "Spring-loaded silent check valve (preferred where pump cycling produces water hammer)"
−```
−
−# Subgrade Preparation {toc}
−
−## The perimeter drain trench shall be excavated to provide a continuous slope from the high point of the loop (or from the building corner farthest from the outlet) to the outlet point or sump pit.
−
−## The bottom of the trench shall be smooth, free of large rocks or debris that would create high points in the pipe alignment, and stable enough to support the pipe and envelope without settlement.
−
−## Soft, organic, or saturated subgrade shall be over-excavated and replaced with compacted granular fill before the drainage envelope is placed.
−
−## The bottom of the perimeter drain pipe shall be at or below the top of the footing per IRC R405 and IBC 1805.4, so that water collected by the drain is below the lowest interior floor elevation it is protecting.
−
−## Setting the drain at the elevation of the bottom of the footing or 2 in. to 4 in. below it is preferred in hydrostatic conditions because it provides drawdown of the groundwater table below the slab elevation, not merely at it. {note}
−
−## Perimeter Drain Invert Datasheet {toc}
−
−```datasheet
−label: Perimeter Drain — Invert Elevation Relative to Bottom of Footing
−type: select
−options:
− - "At top of footing (IRC R405 minimum)"
− - "At bottom of footing (preferred for hydrostatic conditions)"
− - "2 in. to 4 in. below bottom of footing (recommended for hydrostatic conditions with finished basement)"
−drawing_ref: true
−default: "At bottom of footing (preferred for hydrostatic conditions)"
−```
−
−# Drain Pipe Installation {toc}
−
−## The perimeter drain pipe shall be installed to the alignment, invert elevations, and slope shown on the drawings, [[drawing: as detailed on the foundation plan and section drawings showing pipe alignment, invert elevations at corners and cleanouts, and outlet location]].
−
−## Pipe joints shall be made with the manufacturer's couplings or fittings, and field-cut pipe ends shall be deburred and cleaned before assembly.
−
−## Mechanical wraps of duct tape, plastic sheeting, or other field-improvised joint methods shall not be used.
−
−## Pipe slope shall be continuous from the high point to the outlet, without sags or backfall.
−
−## The installer shall check the slope with a level or laser at intervals not exceeding 10 ft and shall correct any sag before the aggregate envelope is placed.
−
−## A 1-in. sag in a 4-in.-diameter drain pipe is a substantial loss of flow capacity at that point; a sag deep enough to hold water is a sediment trap that will become permanently obstructed within the first few groundwater inflow events. {note}
−
−## Changes in direction shall be made with manufactured fittings (sweeps or elbows), not with field-cut miters or notches.
−
−## At 90-degree corners of the building footprint, two 45-degree fittings with a short straight pipe between them are preferred over a single 90-degree elbow because the gentler turn maintains flow capacity and provides a rodding access point for cleanout maintenance.
−
−## Cleanouts {toc}
−
−### Cleanouts shall be provided at the high point of every drain run, at every change of direction greater than 45 degrees, and at maximum 100-ft intervals along straight runs.
−
−### The cleanout shall extend to a finished grade or accessible location with a removable cover, [[drawing: cleanout locations shown on foundation plan]].
−
−### A perimeter drain without accessible cleanouts is a perimeter drain that cannot be maintained, and an unmaintainable drain that has accumulated 10 years of sediment is functionally a sealed pipe. {note}
−
−### Cleanout Spacing and Location Datasheets {toc}
−
−```datasheet
−label: Cleanout Spacing — Maximum Along Straight Runs
−type: select
−unit: ft
−options:
− - "50 ft"
− - "100 ft"
− - "150 ft"
−default: "100 ft"
−```
−
−```datasheet
−label: Cleanout Locations Required
−type: checkbox
−options:
− - "High point of every drain run"
− - "Every change of direction greater than 45 degrees"
− - "Each building corner"
− - "At maximum spacing along straight runs per cleanout spacing setting"
− - "At sump pit connection"
−default: "High point of every drain run"
−```
−
−# Aggregate Envelope {toc}
−
−## The drainage aggregate envelope shall be placed around the drain pipe to the dimensions specified above.
−
−## The pipe shall be bedded on a minimum 2-in. layer of envelope aggregate before placement of the pipe, the aggregate shall be placed evenly around and over the pipe, and the envelope shall be brought to its specified depth before any cover material is placed.
−
−## Envelope aggregate shall be placed by hand or by light equipment in a manner that does not displace the drain pipe from its set alignment or slope.
−
−## Direct dumping of aggregate from a loader bucket onto an unsupported drain pipe is a common installation error that pushes the pipe out of alignment, breaks pipe joints, or punctures the pipe. {note}
−
−# Filter Fabric Installation {toc}
−
−## The nonwoven filter fabric shall be installed in a continuous wrap around the entire aggregate envelope, with seam laps of not less than 12 in., shingled to shed water away from the building face.
−
−## The fabric wrap shall be continuous along the full length of the perimeter drain.
−
−## The fabric shall be installed against the trench wall (on the outside face of the aggregate envelope) so that the envelope is fully enclosed by the fabric and the soil cannot contact the envelope aggregate directly at any point.
−
−## The fabric shall extend up the trench wall and shall be lapped over the top of the envelope before backfill is placed.
−
−## Where backfill is placed in lifts, the top fabric lap shall remain in place until the first lift of backfill is placed to hold the fabric down.
−
−## Filter Fabric Seam Lap Datasheet {toc}
−
−```datasheet
−label: Filter Fabric Seam Lap (minimum)
−type: select
−unit: in
−options:
− - "12 in."
− - "18 in."
− - "24 in. (recommended where significant differential settlement is anticipated)"
−default: "12 in."
−```
−
−## A common installation error is to wrap the perimeter drain pipe in fabric (a "sock") and omit the envelope wrap; the sock alone clogs from the outside in when fine-grained soil contacts the fabric, even where envelope aggregate is provided around the sock, whereas the correct installation is fabric wrapped around the entire aggregate envelope with the aggregate acting as the primary filter and the fabric as the fines barrier between aggregate and soil. {note}
−
−# Drainage Composite Installation (Walls) {toc}
−
−## The drainage composite shall be installed against the waterproofed wall face after the waterproofing membrane has cured, after the membrane has passed any required flood testing or electronic leak detection per [[sync/below-grade-waterproofing]], and after the protection course (where required by the waterproofing manufacturer) has been installed.
−
−## The composite shall be installed before backfill is placed against the wall.
−
−## The composite shall be installed with the dimpled core against the wall (or against the protection course) and the geotextile fabric face outward toward the soil.
−
−## Adjacent panels shall be installed with side laps in accordance with the manufacturer's instructions, typically with the geotextile flap of one panel overlapping the dimpled core of the adjacent panel to provide continuous filtration across the seam.
−
−## Panels shall be fastened to the wall using the manufacturer's specified adhesive, mastic tabs, or mechanical fasteners, and fasteners that penetrate the waterproofing membrane shall not be used.
−
−## The bottom edge of the composite shall terminate within the perimeter drain aggregate envelope, behind the envelope filter fabric wrap, so that water flowing down the composite face discharges directly into the aggregate envelope without crossing a fabric layer that could clog over time.
−
−## The top edge of the composite shall terminate at the design termination height (typically at or just below finished grade) with a termination strip that prevents the entry of soil, root material, and debris into the composite core from the top.
−
−## The geotextile fabric face shall extend slightly above the dimpled core at the top termination and shall be sealed against the wall with the manufacturer's termination strip or with a compatible sealant.
−
−## Drainage Composite Top Termination Datasheet {toc}
−
−```datasheet
−label: Drainage Composite — Top Termination
−type: radio
−options:
− - "Manufacturer's prefabricated termination strip, sealed to wall with compatible sealant"
− - "Geotextile face wrapped over top edge of core and adhered to wall above core"
− - "Top edge buried below finished grade, geotextile only at top edge (acceptable where surface water entry is precluded by other site grading)"
−drawing_ref: true
−default: "Manufacturer's prefabricated termination strip, sealed to wall with compatible sealant"
−```
−
−# Sub-Slab Drainage {toc}
−
−## Where the design groundwater condition is hydrostatic or intermittently hydrostatic, a continuous open-graded granular drainage layer shall be installed beneath the slab on grade, connected to the perimeter drain at the slab edge.
−
−## The sub-slab drainage layer relieves hydrostatic pressure beneath the slab, provides a capillary break against moisture migration into the slab, and provides a drainage path that conveys sub-slab water to the perimeter drain. {note}
−
−## Sub-Slab Drainage Layer Datasheet {toc}
−
−```datasheet
−label: Sub-Slab Drainage Layer — Required
−type: radio
−options:
− - "Yes — minimum 4-in. open-graded granular drainage layer, connected to perimeter drain (non-hydrostatic conditions where Engineer requires capillary break)"
− - "Yes — minimum 6-in. open-graded granular drainage layer, connected to perimeter drain (intermittently hydrostatic conditions)"
− - "Yes — minimum 8-in. open-graded granular drainage layer with internal collector pipes connected to sump (continuously hydrostatic conditions)"
− - "No — non-hydrostatic condition, structural sub-base only (coordinate moisture protection with below-slab vapor barrier scope)"
−drawing_ref: true
−default: "Yes — minimum 6-in. open-graded granular drainage layer, connected to perimeter drain (intermittently hydrostatic conditions)"
−```
−
−## The sub-slab drainage layer aggregate shall be the same washed open-graded gradation specified for the perimeter envelope, or another open-graded gradation approved by the Engineer.
−
−## Pit-run sand, recycled concrete fines, or graded structural sub-base materials with significant fines content shall not be substituted, because they do not have the void space required to function as a drainage layer.
−
−## In continuously hydrostatic conditions or where the slab footprint is large, internal collector pipes within the sub-slab drainage layer shall be provided at a maximum spacing to be determined by the Engineer, draining to the perimeter drain or to a sump pit.
−
−## A large slab over a continuous drainage layer without internal collectors relies on lateral flow across the slab footprint to reach the perimeter drain; this lateral flow is hydraulically limited and is insufficient under design hydrostatic conditions in large-footprint buildings. {note}
−
−## Coordinate the sub-slab drainage layer placement with the underslab waterproofing membrane placement per [[sync/below-grade-waterproofing]].
−
−## Where an underslab waterproofing membrane is specified, the drainage layer shall be placed beneath the membrane, not between the membrane and the slab.
−
−# Crawl-Space Drainage {toc}
−
−## Where a crawl space is below the level at which adjacent grade can drain to daylight, a perimeter drain shall be installed within or just outside the crawl-space wall, conforming to the perimeter drainage requirements of this standard.
−
−## Where the crawl-space floor is below the available daylight elevation, an interior sump pit and pump shall be provided per the Sump Pit and Pump Assembly requirements above.
−
−## The crawl-space ground surface shall be graded to drain toward the sump pit, covered with a vapor retarder per the project's vapor retarder scope, and provided with sufficient access to permit periodic inspection of the sump and the perimeter drain cleanouts.
−
−# Discharge {toc}
−
−## The discharge point of the foundation drainage system shall conform to the design basis selection (daylight, dry well, or storm drainage system), shall comply with the local Authority Having Jurisdiction rules, and shall be detailed on the contract drawings.
−
−## Discharge to daylight shall be located such that the discharged water does not flow back toward the building foundation, does not cross adjacent properties without an easement, and does not discharge onto public right-of-way without permit.
−
−## A minimum horizontal distance of 10 ft from the foundation is required by most jurisdictions, with greater distance preferred where site conditions permit.
−
−## The daylight outlet shall be protected against rodent and debris entry with a screened cover and shall be located for visual inspection accessibility, [[drawing: daylight outlet point and rodent screen as shown on civil grading drawings]].
−
−## Discharge to a storm drainage system shall be made through a positive connection at an approved junction structure (catch basin, manhole, or junction box) rather than by an unconnected outlet pipe into a storm pipe.
−
−## The connection elevation shall be above the design hydraulic grade line of the storm system at the connection point, and the connection shall be coordinated with [[sync/storm-drainage]].
−
−## A foundation drain that connects below the storm system's hydraulic grade line will be backflooded during storm events, defeating the foundation drainage function. {note}
−
−## Discharge to a dry well or infiltration structure shall be permitted by the local Authority Having Jurisdiction and shall be sized for the design flow.
−
−## Dry wells are not appropriate in low-percolation soils or where the seasonal high water table is at or near the dry well bottom elevation; in those conditions a dry well becomes a passive reservoir against the foundation rather than an infiltration outlet. {note}
−
−## Discharge Distance and Sanitary Sewer Datasheets {toc}
−
−```datasheet
−label: Discharge — Minimum Horizontal Distance from Foundation
−type: select
−unit: ft
−options:
− - "10 ft"
− - "20 ft"
− - "Per local jurisdiction requirement (verify before installation)"
−default: "10 ft"
−```
−
−```datasheet
−label: Discharge to Sanitary Sewer
−type: radio
−options:
− - "Prohibited — foundation drainage shall not discharge to sanitary sewer"
−default: "Prohibited — foundation drainage shall not discharge to sanitary sewer"
−```
−
−# Coordination with Waterproofing {toc}
−
−## The drainage system and the below-grade waterproofing system are interdependent and shall be sequenced and detailed so that each system performs its function without interfering with the other.
−
−## The waterproofing membrane shall be installed and shall have passed any required field testing per [[sync/below-grade-waterproofing]] before the drainage composite is installed against it.
−
−## Drainage composite installed over an unverified membrane traps any membrane defects under the composite, where they cannot be located or repaired without removing the composite. {note}
−
−## The drainage composite shall not be fastened with penetrating mechanical fasteners that breach the waterproofing membrane.
−
−## Only adhesive, mastic-tab, or termination-bar attachment methods specified by the waterproofing manufacturer and the drainage composite manufacturer for use together shall be used.
−
−## The perimeter drain aggregate envelope shall be in place and the filter fabric wrap shall be partially placed before the drainage composite is installed, so that the drainage composite bottom edge can be terminated within the envelope under the fabric wrap.
−
−## The fabric wrap shall then be completed over the composite-envelope intersection.
−
−## The sub-slab drainage layer shall be installed beneath the underslab waterproofing membrane where one is specified, not between the membrane and the slab.
−
−## The underslab waterproofing scope and the sub-slab drainage scope shall be coordinated in the pre-installation conference.
−
−## The most common error is installation of the drainage layer after the membrane, which both compromises the membrane and traps the drainage layer in the wrong elevation. {note}
−
−# Testing {toc}
−
−## Functional Flow Test {toc}
−
−### A functional flow test shall be performed on the installed perimeter drain system after pipe installation and envelope placement but before final backfill, and again after backfill at the discharge outlet.
−
−### The test verifies that water introduced at the high point of the drain (or at a cleanout) flows by gravity to the outlet at the design flow rate and that no segment of the drain is plugged, sagged, or misaligned. {note}
−
−### Functional Flow Test Procedure Datasheet {toc}
−
−```datasheet
−label: Functional Flow Test — Procedure
−type: radio
−options:
− - "Introduce clean water at high-point cleanout at a rate of at least 5 gpm; verify continuous discharge at outlet within 5 minutes"
− - "Introduce clean water at high-point cleanout at a rate equal to design flow; verify continuous discharge at outlet within 10 minutes"
− - "Camera inspection of full pipe length (preferred for long runs or where access is critical)"
−default: "Introduce clean water at high-point cleanout at a rate of at least 5 gpm; verify continuous discharge at outlet within 5 minutes"
−```
−
−### The Contractor shall introduce clean water at the high-point cleanout at a controlled rate and shall observe the discharge at the outlet point.
−
−### The time from water introduction to discharge appearance, the visible discharge rate, and any observed surface flooding along the pipe alignment shall be recorded.
−
−### If discharge does not appear at the outlet within the test duration, or if the discharge rate is materially lower than the introduction rate, the system shall be camera-inspected to locate the obstruction, the obstruction shall be corrected, and the test shall be repeated.
−
−### Where the discharge is pumped from a sump, the pump shall be exercised through at least three on-off cycles using clean water introduced to the pit.
−
−### The pump-on float setpoint, the pump-off float setpoint, the high-water alarm float setpoint, and the alarm signal (audible and remote, where specified) shall be verified during the test.
−
−### The check valve shall be verified to prevent backflow into the pit when the pump cycles off.
−
−### Sump Pump Test Datasheets {toc}
−
−```datasheet
−label: Sump Pump Functional Test — Cycles Required
−type: select
−options:
− - "3 on-off cycles minimum"
− - "5 on-off cycles minimum"
− - "Manufacturer-recommended start-up procedure plus 3 cycles"
−default: "3 on-off cycles minimum"
−```
−
−```datasheet
−label: Sump Pump Test — Verifications Required
−type: checkbox
−options:
− - "Pump-on float setpoint"
− - "Pump-off float setpoint"
− - "High-water alarm float setpoint"
− - "Audible alarm signal"
− - "Remote alarm signal to BMS or monitoring service (where specified)"
− - "Check valve prevents backflow into pit"
− - "Discharge piping watertight at all joints"
−default: "Pump-on float setpoint"
−```
−
−## Visual Inspection Before Backfill {toc}
−
−### The installed perimeter drain, aggregate envelope, and filter fabric wrap shall be visually inspected before backfill begins.
−
−### The inspection shall confirm pipe alignment and slope, envelope dimensions, full fabric coverage with seam laps, cleanout locations, and connection of the drainage composite (where present) to the envelope.
−
−### Deficiencies shall be corrected before backfill is permitted.
−
−# Cleaning and Final Acceptance {toc}
−
−## After successful completion of the functional flow test and sump pump test (where applicable), the Contractor shall flush the perimeter drain system with clean water at each cleanout to remove construction sediment, shall verify that the discharge outlet is clear of debris, and shall confirm that all cleanout covers are accessible at finished grade.
−
−## The Contractor shall submit the closeout submittals listed above.
−
−## Final acceptance of the foundation drainage system shall be contingent on satisfactory functional flow test results, satisfactory sump pump test results (where applicable), and acceptance of the record drawings showing as-installed conditions.
−
−# Common Errors and Risk Areas {toc}
−
−## This section summarizes the conditions and installation practices that most frequently generate RFIs, change orders, warranty claims, and basement water-entry complaints in foundation drainage projects. {note}
−## These are documented patterns from field investigations, not theoretical risks. {note}
−
−## No filter fabric, or fabric only around the pipe ("sock") in fine-grained soil, is the most common installation error: the aggregate envelope clogs from the outside in within the first few years of service and the drain stops functioning. {note}
−
−## Fabric shall wrap the entire envelope, with the aggregate acting as the primary filter and the fabric acting as the fines barrier between aggregate and soil.
−
−## Backfall (sag) in the drain pipe holds water permanently, traps sediment, and reduces flow capacity at that point. {note}
−
−## Slope shall be verified with a level or laser at intervals not exceeding 10 ft before envelope placement.
−
−## Unwashed pit-run stone substituted for washed open-graded aggregate clogs the envelope from within and degrades drainage from the first day. {note}
−
−## The aggregate gradation report shall confirm percent passing the No. 200 sieve is less than 2 percent.
−
−## A sump pump with no battery or generator backup has no protection against the most common cause of pump failure during a flood event — utility outage during a storm. {note}
−
−## Battery backup, generator backup, or duplex pumps shall be provided for any sump serving a finished or occupied below-grade space.
−
−## A high-water alarm not installed or not wired leaves pump failures silent until the water is on the floor. {note}
−
−## A high-water alarm float independent of the pump on/off floats shall be provided in every sump pit.
−
−## Discharge of foundation drainage to a sanitary sewer is prohibited in nearly all jurisdictions and shall not be specified or installed.
−
−## Discharge shall be made only to an approved storm drainage system, to daylight, or to a permitted dry well.
−
−## A daylight outlet that is not freeze-protected can freeze shut during winter and convert the perimeter drain into a sealed pressurized system holding water against the foundation. {note}
−
−## Outlets shall be located below frost depth or shall be heat-traced.
−
−## Cleanouts omitted or buried below finished grade leave a drain that cannot be flushed or camera-inspected and that accumulates sediment until it is functionally a sealed pipe. {note}
−
−## Cleanouts shall be provided per the spacing requirements above and shall terminate at finished grade with a removable cover.
−
−## Drainage composite installed over an untested waterproofing membrane traps any membrane defects under the composite where they cannot be located or repaired. {note}
−
−## Waterproofing testing shall be complete before composite installation.
−
−## A drainage composite bottom edge terminated above the envelope rather than within it relies on the soil-side fabric to convey water into the envelope and clogs over time at that localized high-flow zone. {note}
−
−## The composite bottom edge shall terminate within the envelope, behind the envelope filter fabric wrap.
−
−## A perimeter drain connected to a storm system below the storm hydraulic grade line is backflooded during the exact storm events the drain is supposed to protect against. {note}
−
−## The connection elevation shall be above the design hydraulic grade line of the storm system at the connection point.
−
−## Pipe perforations facing up in clean granular soil leave the pipe invert full of standing water and reduce the effective flow capacity. {note}
−
−## Perforations shall face downward unless the manufacturer's installation instructions specifically require otherwise.
−
−## A sump pit undersized for the design flow forces the pump to cycle on and off rapidly during inflow events, shortening pump motor life and prematurely failing the pump. {note}
−
−## The pit shall be sized for the design flow and the pump curve to limit cycling to manufacturer-recommended frequency.
+---
+title: Foundation Drainage
+category: Building Envelope
+description: >
+ When to use: Perimeter and sub-slab drainage protecting below-grade structures on commercial, institutional, and residential projects. Covers the design groundwater basis, perforated thermoplastic perimeter drain pipe, open-graded aggregate envelopes, geotextile filtration, prefabricated wall drainage composites, sub-slab drainage layers and collector piping, crawl space drainage, cleanouts, sump pits with pumps and alarms, gravity and pumped discharge, sequencing with below-grade waterproofing, and field verification before concealment.
+ Not intended for: Below-grade waterproofing and dampproofing membranes (see [[sync/below-grade-waterproofing]]); storm drainage piping, inlets, and structures downstream of the foundation drainage outlet (see [[sync/storm-drainage]]); subgrade preparation, structural backfill, and compaction (see [[sync/earthwork]]); aggregate base course serving a structural rather than a drainage function (see [[sync/aggregate-base-course]]); pavement edge drains; landscape, planter, athletic field, and agricultural subsoil drainage; temporary construction dewatering.
+---
+
+# Scope {toc}
+
+## This standard governs the design basis, materials, installation, and field verification of foundation drainage systems serving below-grade structures. {note}
+
+## The system covered by this standard comprises the components listed below. {note}
+- The perimeter footing drain and its fittings, cleanouts, and observation ports
+- The open-graded aggregate envelope surrounding the perimeter drain
+- The geotextile separating that envelope from the adjacent soil or backfill
+- Prefabricated drainage composites installed over waterproofed below-grade walls
+- The granular drainage layer and collector piping beneath slabs on grade
+- Crawl space perimeter and floor drainage
+- Sump pits, pumps, controls, and alarms where the outlet cannot be reached by gravity
+- The discharge piping between the drainage system and its approved outlet
+
+## Foundation drainage and below-grade waterproofing perform different functions within the same assembly. {note}
+
+## Waterproofing resists the passage of water through the enclosure; drainage removes water from the soil adjacent to the enclosure so that head does not develop against it. {note}
+
+## An assembly that relies on the membrane alone holds standing head against the membrane for the service life of the building, a more severe service condition than the same membrane sees behind a functioning drain. {note}
+
+## An assembly that relies on drainage alone admits water whenever drainage capacity is exceeded, which occurs on outlet blockage, pump failure, a frozen daylight outlet, or a storm event larger than the design event. {note}
+
+## Requirements for the waterproofing membrane, its field testing, and its protection course are governed by [[sync/below-grade-waterproofing]] and are outside this scope. {note}
+
+## Excavation, backfill placement, and compaction are governed by [[sync/earthwork]], and the storm drainage system downstream of the outlet connection is governed by [[sync/storm-drainage]]. {note}
+
+# Referenced Standards {toc}
+
+## Materials, testing, and installation shall comply with the latest adopted edition of each of the following unless a specific edition is cited.
+## Where referenced standards conflict, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.
+
+| Standard | Title |
+|----------|-------|
+| IBC Section 1805.4 | Foundation Drainage (International Building Code) |
+| IRC Section R405 | Foundation Drainage (International Residential Code) |
+| NFPA 70 | National Electrical Code |
+| UL 778 | Motor-Operated Water Pumps |
+| ASTM C33 | Standard Specification for Concrete Aggregates |
+| ASTM D448 | Standard Classification for Sizes of Aggregate for Road and Bridge Construction |
+| ASTM D2412 | Standard Test Method for Determination of External Loading Characteristics of Plastic Pipe by Parallel-Plate Loading |
+| ASTM D2729 | Standard Specification for Poly(Vinyl Chloride) (PVC) Sewer Pipe and Fittings |
+| ASTM D3034 | Standard Specification for Type PSM Poly(Vinyl Chloride) (PVC) Sewer Pipe and Fittings |
+| ASTM D4491 | Standard Test Methods for Water Permeability of Geotextiles by Permittivity |
+| ASTM D4632 | Standard Test Method for Grab Breaking Load and Elongation of Geotextiles |
+| ASTM D4716 | Standard Test Method for Determining the (In-Plane) Flow Rate per Unit Width and Hydraulic Transmissivity of a Geosynthetic Using a Constant Head |
+| ASTM D4751 | Standard Test Methods for Determining Apparent Opening Size of a Geotextile |
+| ASTM D4833 | Standard Test Method for Index Puncture Resistance of Geomembranes and Related Products |
+| ASTM D5101 | Standard Test Method for Measuring the Filtration Compatibility of Soil-Geotextile Systems |
+| ASTM D6707 | Standard Specification for Circular-Knit Geotextile for Use in Subsurface Drainage Applications |
+| ASTM D7001 | Standard Specification for Geocomposites for Pavement Edge Drains and Other High-Flow Applications |
+| ASTM D7140 | Standard Test Method to Measure Resistance of Geosynthetic Drainage Composites to Compressive Creep |
+| ASTM F405 | Standard Specification for Corrugated Polyethylene (PE) Pipe and Fittings |
+| ASTM F667 | Standard Specification for 3 through 24 in. Corrugated Polyethylene Pipe and Fittings |
+| ASTM F758 | Standard Specification for Smooth-Wall Poly(Vinyl Chloride) (PVC) Plastic Underdrain Systems for Highway, Airport, and Similar Drainage |
+| ASTM F949 | Standard Specification for Poly(Vinyl Chloride) (PVC) Corrugated Sewer Pipe with a Smooth Interior and Fittings |
+| AASHTO M252 | Standard Specification for Corrugated Polyethylene Drainage Pipe |
+| AASHTO M288 | Geotextile Specification for Highway Applications |
+| AASHTO M294 | Standard Specification for Corrugated Polyethylene Pipe, 12 in. to 60 in. Diameter |
+
+# Submittals {toc}
+
+## Action Submittals {toc}
+
+### The Contractor shall submit the items indicated in the datasheet for the Engineer of Record's review before procurement of foundation drainage materials.
+- Product data for perimeter drain pipe, fittings, and cleanouts, including perforation pattern and opening size, joint type, and published pipe stiffness
+- Aggregate gradation report from the supplier, reporting the full sieve analysis and the percent passing the No. 200 sieve
+- Geotextile test reports covering apparent opening size per ASTM D4751, permittivity per ASTM D4491, grab tensile per ASTM D4632, and puncture resistance per ASTM D4833
+- Wall drainage composite test reports covering in-plane flow rate per ASTM D4716 at the design normal stress and hydraulic gradient
+- Wall drainage composite compressive creep test report per ASTM D7140
+- Soil-geotextile filtration compatibility report per ASTM D5101
+- Sump pump product data, including the published pump curve, motor data, float and control arrangement, alarm devices, and pit dimensions
+- Shop drawings showing perimeter drain alignment, invert elevations at corners and cleanouts, slope, cleanout locations, sump pit location, discharge routing, and the outlet connection detail
+- Installer qualification statement
+
+```datasheet
+label: Action Submittals Required
+type: checkbox
+options:
+ - "Product data for drain pipe, fittings, and cleanouts"
+ - "Aggregate gradation report"
+ - "Geotextile test reports"
+ - "Wall drainage composite in-plane flow rate report"
+ - "Wall drainage composite compressive creep report"
+ - "Soil-geotextile filtration compatibility report"
+ - "Sump pump product data and control arrangement"
+ - "Shop drawings for alignment, inverts, cleanouts, and discharge"
+ - "Installer qualification statement"
+default:
+ - "Product data for drain pipe, fittings, and cleanouts"
+ - "Aggregate gradation report"
+ - "Geotextile test reports"
+ - "Shop drawings for alignment, inverts, cleanouts, and discharge"
+ - "Installer qualification statement"
+```
+
+### The aggregate gradation report shall be dated not more than 6 months before the date of the delivery it represents.
+
+### No portion of the foundation drainage installation shall proceed until the action submittals covering that portion have been reviewed and returned.
+
+## Closeout Submittals {toc}
+
+### The Contractor shall submit the items indicated in the datasheet before the foundation drainage system is accepted.
+- Record drawings showing as-installed perimeter drain alignment, invert elevations at corners and cleanouts, cleanout locations, sump pit location, and the outlet point
+- Perimeter drain verification report signed by the technician who performed the verification
+- Sump pump start-up report recording the pump-down test, alarm verification, and float setpoints as left
+- Manufacturer's written warranties for sump pumps, controls, and check valves, made out to the Owner
+- Operation and maintenance manual covering pump operation, cleanout access locations, inspection intervals, and the outlet inspection procedure
+
+```datasheet
+label: Closeout Submittals Required
+type: checkbox
+options:
+ - "Record drawings of as-installed alignment, inverts, and cleanouts"
+ - "Perimeter drain verification report"
+ - "Sump pump start-up report"
+ - "Manufacturer's written warranties made out to the Owner"
+ - "Operation and maintenance manual"
+default:
+ - "Record drawings of as-installed alignment, inverts, and cleanouts"
+ - "Perimeter drain verification report"
+ - "Sump pump start-up report"
+ - "Manufacturer's written warranties made out to the Owner"
+ - "Operation and maintenance manual"
+```
+
+# Quality Assurance {toc}
+
+## Installer Qualifications {toc}
+
+### Foundation drainage shall be installed by a Contractor who has completed below-grade drainage work of comparable scope and comparable groundwater conditions on at least three projects.
+
+### Sump pump piping and electrical connections shall be performed by subcontractors licensed for that work where the Authority Having Jurisdiction requires a license.
+
+## Pre-Installation Conference {toc}
+
+### A pre-installation conference shall be held at the site before foundation drainage installation begins.
+
+### The conference shall be attended by the Engineer of Record or the Owner's Representative, the General Contractor, the earthwork subcontractor, the waterproofing subcontractor, the drainage installer, and the electrical subcontractor where a sump pump is provided.
+
+### The conference shall cover sequencing among excavation, waterproofing, drainage placement, and backfill; coordination of the perimeter drain invert with the bottom-of-footing elevation; protection of the waterproofing membrane; cleanout locations; the sump and outlet connection; and the verification plan.
+
+### Minutes shall be recorded by the General Contractor and distributed to all attendees within 5 working days.
+
+## Inspection Before Concealment {toc}
+
+### The installed perimeter drain, aggregate envelope, and geotextile shall be available for inspection by the Authority Having Jurisdiction and by the Engineer of Record before backfill is placed.
+
+### The Contractor shall give the Engineer of Record not less than 3 working days notice of the date the installation will be ready for inspection.
+
+### Work concealed before the required inspection shall be uncovered at the Contractor's cost and reinstated after inspection.
+
+# Design Groundwater Basis {toc}
+
+## The Engineer of Record shall establish the design groundwater elevation and the seasonal high water table elevation from a site-specific geotechnical investigation.
+
+## The foundation drainage system shall be designed for the seasonal high water table elevation rather than the average groundwater elevation.
+
+## A system sized for the average elevation is at capacity during the spring thaw and extended rain events, which are the conditions that produce the loading the system exists to relieve. {note}
+
+## The design groundwater condition shall be as indicated in the datasheet and shall be the same condition used for the [[sync/below-grade-waterproofing]] scope.
+
+```datasheet
+label: Design Groundwater Condition
+type: radio
+options:
+ - "Non-hydrostatic"
+ - "Intermittently hydrostatic"
+ - "Continuously hydrostatic"
+drawing_ref: "geotechnical investigation report"
+default: deferred
+```
+
+## The three design groundwater conditions are distinguished by where the seasonal high water table stands relative to the below-grade assembly. {note}
+- Non-hydrostatic: the seasonal high water table remains below the underside of the lowest slab, and the drainage system handles perched water, infiltration through backfill, and roof and grade runoff
+- Intermittently hydrostatic: the seasonal high water table rises into the below-grade assembly for part of the year
+- Continuously hydrostatic: the water table stands at or above the lowest slab elevation for most of the year
+
+## Where the design groundwater condition is intermittently or continuously hydrostatic, a prefabricated wall drainage composite shall be provided over the waterproofed face of below-grade walls.
+
+## Where the design groundwater condition is continuously hydrostatic, a sub-slab drainage layer with collector piping shall be provided beneath slabs on grade.
+
+## Where the design groundwater condition is non-hydrostatic, the perimeter drain remains required by IBC Section 1805.4 and IRC Section R405 for foundations enclosing habitable or usable space below grade.
+
+# Discharge Conveyance and Outlet {toc}
+
+## Water collected by the foundation drainage system shall be conveyed to an approved outlet by the conveyance method indicated in the datasheet.
+
+```datasheet
+label: Discharge Conveyance Method
+type: radio
+options:
+ - "Gravity throughout"
+ - "Pumped from a sump pit"
+drawing_ref: "civil grading plan and foundation plan"
+default: deferred
+```
+
+## A gravity outlet has no moving parts, no dependence on electrical service, and no scheduled replacement interval, whereas a pumped outlet depends on a pump of finite service life, on continuous electrical service, and on an alarm that is maintained. {note}
+
+## The discharge destination shall be as indicated in the datasheet.
+
+```datasheet
+label: Discharge Destination
+type: radio
+options:
+ - "Daylight outlet"
+ - "Storm drainage system"
+ - "Dry well or other infiltration structure"
+drawing_ref: "civil grading plan"
+default: deferred
+```
+
+## Foundation drainage shall not be discharged to a sanitary sewer.
+
+## The Contractor shall confirm the permitted discharge destination with the Authority Having Jurisdiction before procuring sump, pump, or outlet materials.
+
+## Where the Authority Having Jurisdiction prohibits the discharge destination indicated in the datasheet, the Contractor shall notify the Engineer of Record before proceeding.
+
+## Daylight Outlet {toc}
+
+### The daylight outlet shall be located so that discharged water flows away from the foundation and does not return toward the building.
+
+### The daylight outlet shall be located not less than the horizontal distance indicated in the datasheet from the outside face of the foundation wall.
+
+```datasheet
+label: Daylight Outlet - Minimum Horizontal Distance from Foundation
+type: range
+unit: ft
+min: 5
+max: 50
+setpoints: [5, 10, 15, 20, 30, 50]
+drawing_ref: "civil grading plan"
+default: deferred
+```
+
+### The daylight outlet shall not discharge across an adjacent property without a recorded easement and shall not discharge onto a public right-of-way without a permit.
+
+### The daylight outlet shall be fitted with a rodent and debris screen that can be removed for cleaning without excavation.
+
+### The daylight outlet shall be located where it can be seen and reached for inspection after final grading and landscaping are complete.
+
+### Freeze protection of the daylight outlet shall be as indicated in the datasheet.
+
+```datasheet
+label: Daylight Outlet - Freeze Protection
+type: radio
+options:
+ - "Outlet invert located below the local frost depth"
+ - "Insulated and heat-traced outlet riser"
+ - "No freeze protection provided"
+ - "Not applicable - no daylight outlet"
+```
+
+### Where the site is subject to sustained sub-freezing conditions, the daylight outlet shall be freeze-protected by one of the methods indicated in the datasheet.
+
+### An outlet that freezes closed converts the perimeter drain into a closed pipe holding water against the foundation, which is the condition the drain exists to prevent. {note}
+
+## Storm Drainage Connection {toc}
+
+### The connection to a storm drainage system shall be made at an approved junction structure rather than by an open pipe end discharging into a storm pipe.
+
+### The invert of the connection shall be above the design hydraulic grade line of the storm drainage system at the point of connection.
+
+### A connection below the storm system's hydraulic grade line is backflooded during the storm events the foundation drain exists to survive. {note}
+
+### The connection detail and the receiving structure shall be coordinated with [[sync/storm-drainage]].
+
+## Dry Well and Infiltration Outlets {toc}
+
+### A dry well or other infiltration structure shall be permitted by the Authority Having Jurisdiction and shall be sized for the design flow of the foundation drainage system.
+
+### Where the seasonal high water table stands at or above the bottom of a dry well, or where the measured infiltration rate of the receiving soil is below the rate required to accept the design flow, the Engineer of Record shall select an alternative discharge destination.
+
+### An infiltration structure that cannot drain becomes a standing reservoir near the foundation rather than an outlet. {note}
+
+# Perimeter Drain Pipe {toc}
+
+## The perimeter drain pipe shall be a perforated thermoplastic pipe of the type indicated in the datasheet.
+
+```datasheet
+label: Perimeter Drain Pipe Type
+type: radio
+options:
+ - "Perforated corrugated polyethylene pipe conforming to ASTM F405 or AASHTO M252"
+ - "Perforated corrugated polyethylene pipe conforming to ASTM F667 or AASHTO M294"
+ - "Perforated dual-wall corrugated polyethylene pipe with a smooth interior"
+ - "Perforated smooth-wall high-density polyethylene pipe"
+ - "Perforated smooth-wall PVC underdrain pipe conforming to ASTM F758"
+ - "Perforated PVC sewer pipe conforming to ASTM D3034"
+ - "Perforated PVC sewer and drain pipe conforming to ASTM D2729"
+ - "Perforated corrugated PVC pipe with a smooth interior conforming to ASTM F949"
+```
+
+## Corrugated pipe has a higher interior friction loss than smooth-wall pipe of the same nominal diameter, so a corrugated run carries less flow than a smooth-wall run at the same slope. {note}
+
+## The nominal pipe diameter shall be as indicated in the datasheet.
+
+```datasheet
+label: Perimeter Drain Pipe - Nominal Diameter
+type: range
+unit: in
+min: 4
+max: 12
+setpoints: [4, 6, 8, 10, 12]
+drawing_ref: "foundation plan and drainage profile"
+default: deferred
+```
+
+## The pipe diameter shall be sized by the Engineer of Record for the design flow, the total run length, and the available slope.
+
+## Adopting the smallest permitted diameter on a long run at minimum slope with several inlet points produces a system that meets the code minimum and not the design flow. {note}
+
+## The minimum pipe slope shall be as indicated in the datasheet and shall account for the interior friction loss of the pipe type selected.
+
+```datasheet
+label: Perimeter Drain Pipe - Minimum Slope
+type: range
+unit: '%'
+min: 0
+max: 5
+setpoints: [0, 0.5, 0.75, 1, 1.5, 2, 3, 5]
+```
+
+## A level perimeter drain is a permitted configuration: the building code does not require foundation drains to slope, because water surrounding the envelope rises into the pipe and flows toward the outlet under the hydraulic gradient rather than under gravity along the invert. A sloped invert drains the pipe itself between events and reduces sediment accumulation, at the cost of additional excavation depth at the downstream end of a long run. {note}
+
+## The minimum pipe stiffness at 5 percent deflection when tested in accordance with ASTM D2412 shall be as indicated in the datasheet.
+
+```datasheet
+label: Perimeter Drain Pipe - Minimum Pipe Stiffness at 5 Percent Deflection
+type: range
+unit: psi
+min: 28
+max: 115
+setpoints: [28, 35, 46, 115]
+```
+
+## Pipe stiffness shall be selected for the depth of cover and the construction loading the pipe will carry before and after backfill.
+
+## Perforations {toc}
+
+### The perforation pattern shall be as indicated in the datasheet.
+
+```datasheet
+label: Drain Pipe Perforation Pattern
+type: radio
+options:
+ - "Circular perforations arrayed in rows"
+ - "Longitudinal slots"
+default: manufacturer
+```
+
+### The perforation opening dimension shall be smaller than the smallest sieve size that retains 90 percent of the envelope aggregate, so that envelope aggregate cannot enter the pipe.
+
+### The manufacturer shall report the perforation pattern and the perforation opening dimension in the action submittals.
+
+### Slot perforations sized to the envelope gradation present a smaller opening for a given inflow area than circular perforations, which reduces the rate at which fines that reach the envelope enter the pipe. {note}
+
+### The perforation orientation shall be as indicated in the datasheet.
+
+```datasheet
+label: Drain Pipe Perforation Orientation
+type: radio
+options:
+ - "Perforations down"
+ - "Perforations up"
+default: "Perforations down"
+```
+
+### Perforations at the invert admit water from the full depth of the surrounding envelope and leave the upper pipe cross-section available as flow capacity during peak inflow. {note}
+
+### Where the pipe manufacturer's published installation instructions call for an orientation other than the one indicated in the datasheet, the Contractor shall notify the Engineer of Record before installation and the Engineer of Record shall direct the orientation to be used.
+
+## Pipe Wrap {toc}
+
+### The pipe wrap shall be as indicated in the datasheet.
+
+```datasheet
+label: Perimeter Drain Pipe - Pipe Wrap
+type: radio
+options:
+ - "Factory-applied circular-knit geotextile sock conforming to ASTM D6707"
+ - "Factory-applied nonwoven geotextile sock"
+ - "No pipe wrap"
+```
+
+### A pipe wrap shall not be substituted for the aggregate envelope or for the envelope geotextile.
+
+### A pipe wrap in fine-grained backfill blinds from the soil side, and the resulting loss of inflow capacity is not visible from the surface and does not trigger an alarm. {note}
+
+# Drainage Aggregate Envelope {toc}
+
+## The drainage aggregate envelope shall be a washed, open-graded crushed stone or gravel of the gradation indicated in the datasheet.
+
+```datasheet
+label: Drainage Envelope Aggregate Gradation
+type: radio
+options:
+ - "ASTM D448 No. 4"
+ - "ASTM D448 No. 57"
+ - "ASTM D448 No. 6"
+ - "ASTM D448 No. 67"
+ - "ASTM D448 No. 8"
+default: "ASTM D448 No. 57"
+```
+
+## The envelope aggregate shall contain not more than 10 percent material passing the No. 4 sieve, as required by IBC Section 1805.4.1.
+
+## The envelope aggregate shall be washed at the source.
+
+## The percent of envelope aggregate passing the No. 200 sieve shall not exceed the value indicated in the datasheet.
+
+```datasheet
+label: Envelope Aggregate - Maximum Material Passing the No. 200 Sieve
+type: range
+unit: '%'
+min: 0.5
+max: 5
+setpoints: [0.5, 1, 2, 3, 5]
+default: 2
+```
+
+## Unwashed pit-run stone shall not be placed in the drainage envelope even where its size gradation falls within the specified envelope.
+
+## Fines delivered with the aggregate are already inside the envelope when it is placed, so no geotextile on the outside of the envelope can exclude them. {note}
+
+## Envelope Dimensions {toc}
+
+### The aggregate bedding beneath the perimeter drain pipe shall be not less than 2 in. thick, as required by IBC Section 1805.4.2 and IRC Section R405.1, and shall be not less than the thickness indicated in the datasheet.
+
+```datasheet
+label: Drainage Envelope - Aggregate Bedding Below Pipe
+type: range
+unit: in
+min: 2
+max: 12
+setpoints: [2, 4, 6, 8, 12]
+drawing_ref: "foundation sections and drainage details"
+default: deferred
+```
+
+### The aggregate cover over the perimeter drain pipe shall be not less than 6 in., as required by IBC Section 1805.4.2 and IRC Section R405.1, and shall be not less than the thickness indicated in the datasheet.
+
+```datasheet
+label: Drainage Envelope - Aggregate Cover Over Pipe
+type: range
+unit: in
+min: 6
+max: 24
+setpoints: [6, 8, 12, 18, 24]
+drawing_ref: "foundation sections and drainage details"
+default: deferred
+```
+
+### The aggregate envelope shall extend not less than 12 in. beyond the outside edge of the footing, as required by IBC Section 1805.4.2 and IRC Section R405.1, and shall extend not less than the distance indicated in the datasheet.
+
+```datasheet
+label: Drainage Envelope - Extension Beyond Outside Edge of Footing
+type: range
+unit: in
+min: 12
+max: 36
+setpoints: [12, 18, 24, 36]
+drawing_ref: "foundation sections and drainage details"
+default: deferred
+```
+
+### The bottom of the perimeter drain pipe shall be no higher than the bottom of the base course beneath the lowest slab, as required by IBC Section 1805.4.2.
+
+### Setting the pipe invert at or below the bottom of the footing draws the water table down below the slab elevation rather than holding it at the slab elevation. {note}
+
+# Envelope Geotextile {toc}
+
+## A geotextile shall be installed between the drainage aggregate envelope and the adjacent soil or backfill on all sides of the envelope.
+
+## The geotextile shall pass water from the soil into the envelope while retaining the soil fines that would otherwise migrate into the envelope and occupy its void space.
+
+## The envelope geotextile determines whether the envelope still has its design void space in year twenty; the aggregate itself does not degrade, but an envelope that has taken in soil fines has no remaining conveyance. {note}
+
+## The geotextile type shall be as indicated in the datasheet.
+
+```datasheet
+label: Envelope Geotextile Type
+type: radio
+options:
+ - "Nonwoven needle-punched geotextile"
+ - "Woven monofilament geotextile"
+default: "Nonwoven needle-punched geotextile"
+```
+
+## Woven slit-film geotextiles shall not be used in subsurface drainage applications, in accordance with AASHTO M288.
+
+## The geotextile strength class per AASHTO M288 shall be as indicated in the datasheet.
+
+```datasheet
+label: Envelope Geotextile - Strength Class per AASHTO M288
+type: select
+options:
+ - "Class 1"
+ - "Class 2"
+ - "Class 3"
+default: "Class 2"
+```
+
+## AASHTO M288 selects the strength class from the severity of installation stress, and Class 2 is its default class for subsurface drainage. {note}
+
+## Filtration Properties {toc}
+
+### The maximum apparent opening size and the minimum permittivity of the envelope geotextile shall be as indicated in the datasheets, and neither shall be less restrictive than the AASHTO M288 subsurface drainage value for the percent of in-situ soil passing the No. 200 sieve reported in the geotechnical investigation.
+
+```datasheet
+label: Envelope Geotextile - Maximum Apparent Opening Size per ASTM D4751
+type: range
+unit: mm
+min: 0.15
+max: 0.6
+setpoints: [0.15, 0.18, 0.22, 0.25, 0.3, 0.43, 0.6]
+```
+
+```datasheet
+label: Envelope Geotextile - Minimum Permittivity per ASTM D4491
+type: range
+unit: 1/s
+min: 0.1
+max: 2
+setpoints: [0.1, 0.2, 0.5, 1, 1.5, 2]
+```
+
+### Apparent opening size and permittivity move against each other: a smaller opening retains finer soil and passes less water, so the pair is selected together for the reported soil rather than each to its own extreme. {note}
+
+### The geotextile shall meet the grab tensile and puncture resistance values of its selected AASHTO M288 strength class, verified by the test reports submitted in the action submittals.
+
+## Filtration Compatibility Evaluation {toc}
+
+### The geotechnical engineer shall determine whether a soil-geotextile filtration compatibility evaluation per ASTM D5101 is required for the in-situ soil, and the determination shall be recorded in the datasheet.
+
+```datasheet
+label: Soil-Geotextile Filtration Compatibility Evaluation per ASTM D5101
+type: radio
+options:
+ - "Required"
+ - "Not required"
+```
+
+### Fine-grained soils, dispersive soils, and internally unstable gap-graded soils carry clogging and piping behavior that apparent opening size and permittivity alone do not predict, which is what the gradient ratio measures. {note}
+
+### Where the evaluation is required, the measured gradient ratio shall not exceed the value indicated in the datasheet.
+
+```datasheet
+label: Soil-Geotextile - Maximum Gradient Ratio per ASTM D5101
+type: range
+min: 1
+max: 3
+setpoints: [1, 1.5, 2, 2.5, 3]
+default: 3
+```
+
+### Where the measured gradient ratio exceeds the specified maximum, the Contractor shall submit a revised geotextile for the Engineer of Record's review before any geotextile is installed.
+
+# Below-Grade Wall Drainage {toc}
+
+## Provision of a prefabricated drainage composite over below-grade walls shall be as indicated in the datasheet.
+
+```datasheet
+label: Wall Drainage Composite
+type: radio
+options:
+ - "Provided over the waterproofed wall face"
+ - "Not provided"
+```
+
+## The composite consists of a dimpled or molded polymer core that holds an open flow channel against the wall, faced on the soil side by a geotextile that retains backfill fines. {note}
+
+## The composite performs three functions in the assembly: it carries water down the wall face to the perimeter drain, it prevents head from developing against the waterproofing membrane, and it shields the membrane from mechanical damage during backfill. {note}
+
+## Backfill against below-grade walls shall be as indicated in the datasheet.
+
+```datasheet
+label: Backfill Against Below-Grade Walls
+type: radio
+options:
+ - "Free-draining granular backfill"
+ - "Site-excavated backfill placed per the earthwork requirements"
+drawing_ref: "foundation sections"
+default: deferred
+```
+
+## Free-draining granular backfill conveys water down the wall face by its own permeability, so a wall backfilled with granular material and a wall protected by a composite address the same load path by different means, and a wall may use either or both. {note}
+
+## Backfill material, lift thickness, and compaction are governed by [[sync/earthwork]]. {note}
+
+## Composite Core and Flow Capacity {toc}
+
+### The minimum core thickness of the wall drainage composite shall be as indicated in the datasheet.
+
+```datasheet
+label: Wall Drainage Composite - Minimum Core Thickness
+type: range
+unit: in
+min: 0.25
+max: 1
+setpoints: [0.25, 0.375, 0.5, 0.625, 1]
+```
+
+### The minimum in-plane flow rate per unit width of the wall drainage composite, tested in accordance with ASTM D4716, shall be as indicated in the datasheet.
+
+```datasheet
+label: Wall Drainage Composite - Minimum In-Plane Flow Rate per ASTM D4716
+type: range
+unit: gpm/ft
+min: 1
+max: 25
+setpoints: [1, 2, 5, 10, 15, 25]
+```
+
+### The in-plane flow rate shall be reported at the normal stress and hydraulic gradient that the composite will see at the deepest point of its installation.
+
+### Core thickness and flow capacity are not interchangeable: a thicker core loaded to collapse conveys less than a thinner core that holds its geometry, which is why the reported test condition governs rather than the nominal thickness. {note}
+
+### Whether compressive creep testing per ASTM D7140 is required shall be as indicated in the datasheet.
+
+```datasheet
+label: Wall Drainage Composite - Compressive Creep Testing per ASTM D7140
+type: radio
+options:
+ - "Required"
+ - "Not required"
+```
+
+### A single flow rate report taken at low normal stress does not describe the composite's behavior after years under the sustained overburden of a deep wall, which is the condition ASTM D7140 measures. {note}
+
+## Composite Geotextile Face {toc}
+
+### The geotextile laminated to the soil side of the wall drainage composite shall meet the apparent opening size and permittivity values specified for the envelope geotextile.
+
+### The Contractor shall confirm the compatibility of the composite manufacturer's laminated geotextile with the backfill soil before the composite is ordered.
+
+### The laminated geotextile is fixed when the composite is manufactured and cannot be exchanged in the field. {note}
+
+## Composite Attachment and Terminations {toc}
+
+### The attachment method for the wall drainage composite shall be as indicated in the datasheet.
+
+```datasheet
+label: Wall Drainage Composite - Attachment Method
+type: radio
+options:
+ - "Adhesive applied to the wall face"
+ - "Mastic tabs"
+ - "Termination bar at the top edge with the panel hanging free below"
+default: manufacturer
+```
+
+### Fasteners that penetrate the waterproofing membrane shall not be used to attach the wall drainage composite.
+
+### The attachment method shall be one that both the waterproofing manufacturer and the composite manufacturer accept for use with each other's product.
+
+### The bottom termination of the wall drainage composite shall be as indicated in the datasheet.
+
+```datasheet
+label: Wall Drainage Composite - Bottom Termination
+type: radio
+options:
+ - "Terminated within the perimeter drain aggregate envelope beneath the envelope geotextile"
+ - "Terminated at the top of the perimeter drain aggregate envelope"
+default: "Terminated within the perimeter drain aggregate envelope beneath the envelope geotextile"
+```
+
+### A composite that stops above the envelope discharges its collected flow onto the outside face of the envelope geotextile at one concentrated line, which is the highest-flux point on the whole geotextile. {note}
+
+### The top termination of the wall drainage composite shall be as indicated in the datasheet.
+
+```datasheet
+label: Wall Drainage Composite - Top Termination
+type: radio
+options:
+ - "Prefabricated termination strip sealed to the wall"
+ - "Geotextile face wrapped over the top edge of the core and adhered to the wall"
+ - "Metal termination bar bedded in sealant"
+default: manufacturer
+```
+
+### The top termination shall close the top of the core against the entry of soil, root material, and debris.
+
+# Sub-Slab Drainage {toc}
+
+## Provision of a sub-slab drainage layer beneath slabs on grade shall be as indicated in the datasheet.
+
+```datasheet
+label: Sub-Slab Drainage Layer
+type: radio
+options:
+ - "Provided beneath slabs on grade"
+ - "Not provided"
+```
+
+## A sub-slab drainage layer relieves uplift pressure beneath the slab, provides a capillary break between the subgrade and the slab, and carries sub-slab water laterally to the perimeter drain. {note}
+
+## The thickness of the sub-slab drainage layer shall be as indicated in the datasheet.
+
+```datasheet
+label: Sub-Slab Drainage Layer - Thickness
+type: range
+unit: in
+min: 4
+max: 12
+setpoints: [4, 6, 8, 10, 12]
+drawing_ref: "foundation plan and slab sections"
+default: deferred
+```
+
+## The sub-slab drainage layer shall be a washed open-graded aggregate of the gradation specified for the perimeter drainage envelope, or another open-graded gradation accepted by the Engineer of Record.
+
+## Pit-run sand, crusher fines, recycled concrete fines, and dense-graded structural sub-base shall not be substituted for the sub-slab drainage layer aggregate.
+
+## Dense-graded material is engineered to minimize void space so that it compacts to a stable bearing surface, which is the opposite of what a drainage layer is asked to do. {note}
+
+## The sub-slab drainage layer shall be connected to the perimeter drain or to the sump pit at the slab edge.
+
+## Provision of collector piping within the sub-slab drainage layer shall be as indicated in the datasheet.
+
+```datasheet
+label: Sub-Slab Collector Piping
+type: radio
+options:
+ - "Provided within the sub-slab drainage layer"
+ - "Not provided"
+```
+
+## The maximum spacing of sub-slab collector piping shall be as indicated in the datasheet.
+
+```datasheet
+label: Sub-Slab Collector Piping - Maximum Spacing
+type: range
+unit: ft
+min: 10
+max: 100
+setpoints: [10, 15, 20, 25, 30, 40, 50, 100]
+drawing_ref: "foundation plan"
+default: deferred
+```
+
+## Lateral flow through a granular layer is driven by the head available across the slab footprint, so on a large footprint the water at the center reaches the perimeter drain slowly or not at all without collectors. {note}
+
+## Where an underslab waterproofing membrane is specified, the sub-slab drainage layer shall be placed beneath that membrane.
+
+## The interface between the sub-slab drainage scope and the underslab waterproofing scope shall be reviewed at the pre-installation conference and coordinated with [[sync/below-grade-waterproofing]].
+
+# Crawl Space Drainage {toc}
+
+## Where a crawl space floor is below the elevation at which adjacent grade drains to daylight, a perimeter drain conforming to this standard shall be installed at the crawl space wall.
+
+## Where the crawl space floor is below the elevation of any available gravity outlet, an interior sump pit and pump conforming to this standard shall be provided.
+
+## The crawl space ground surface shall be graded to fall toward the sump pit or the interior drain inlet.
+
+## Access shall be provided to the crawl space sump, its controls, and the perimeter drain cleanouts for periodic inspection.
+
+## The crawl space vapor retarder is governed by the project's vapor retarder scope and is not part of the drainage scope. {note}
+
+# Sump Pit and Pump Assembly {toc}
+
+## The sump pit shall be sized to receive the design flow at peak inflow and to provide working volume between the pump-on and pump-off setpoints sufficient to hold pump starts within the pump manufacturer's published maximum starts per hour.
+
+## The minimum interior diameter of the sump pit shall be as indicated in the datasheet.
+
+```datasheet
+label: Sump Pit - Minimum Interior Diameter
+type: range
+unit: in
+min: 18
+max: 60
+setpoints: [18, 24, 30, 36, 48, 60]
+drawing_ref: "foundation plan and sump pit detail"
+default: deferred
+```
+
+## A pit that is too small for the inflow shortens the interval between starts, and motor starts rather than running hours are what consume the life of a sump pump. {note}
+
+## The sump pit material shall be as indicated in the datasheet.
+
+```datasheet
+label: Sump Pit Material
+type: select
+options:
+ - "Structural thermoplastic"
+ - "Fiberglass-reinforced polyester"
+ - "Precast concrete"
+```
+
+## The sump pit cover shall be as indicated in the datasheet.
+
+```datasheet
+label: Sump Pit Cover
+type: select
+options:
+ - "Gasketed and mechanically fastened cover sealed for soil-gas control"
+ - "Solid unsealed cover"
+ - "Slotted or grated cover"
+```
+
+## An open or slotted pit within a conditioned or occupied below-grade space is a continuous path between the soil and the interior air. {note}
+
+## Pump Configuration and Standby Power {toc}
+
+### The sump pump configuration shall be as indicated in the datasheet.
+
+```datasheet
+label: Sump Pump Configuration
+type: radio
+options:
+ - "Simplex"
+ - "Duplex with alternating duty"
+ - "Simplex with a battery-backed secondary pump"
+```
+
+### The design discharge capacity of the sump pump shall be as indicated in the datasheet.
+
+```datasheet
+label: Sump Pump - Design Discharge Capacity
+type: range
+unit: gpm
+min: 10
+max: 500
+step: 5
+drawing_ref: "pump schedule"
+default: deferred
+```
+
+### Sump pumps shall be listed to UL 778.
+
+### The standby power arrangement for the sump pump shall be as indicated in the datasheet.
+
+```datasheet
+label: Sump Pump - Standby Power Arrangement
+type: radio
+options:
+ - "Battery-backed inverter dedicated to the sump"
+ - "Building standby generator branch circuit"
+ - "No standby power provided"
+```
+
+### The two failure modes that most often put water on a below-grade floor are failure of the pump itself and loss of utility power, and the second of those arrives with the storm that produces the peak inflow. {note}
+
+### Where the sump serves a finished or occupied below-grade space, the pump configuration shall provide redundancy against pump failure and the standby power arrangement shall provide operation during loss of utility power.
+
+### Sump pump branch circuits, disconnects, and receptacles shall comply with NFPA 70.
+
+## High-Water Alarm {toc}
+
+### A high-water alarm float independent of the pump control floats shall be provided in every sump pit.
+
+### The alarm annunciation shall be as indicated in the datasheet.
+
+```datasheet
+label: High-Water Alarm Annunciation
+type: radio
+options:
+ - "Local audible and visual alarm at the sump"
+ - "Local alarm with remote annunciation to the building automation system"
+ - "Local alarm with remote annunciation to a monitored alarm service"
+default: "Local audible and visual alarm at the sump"
+```
+
+### The high-water alarm shall remain powered when the pump branch circuit is de-energized.
+
+### An alarm that shares the circuit it is watching goes silent for the failure it exists to report. {note}
+
+## Sump Discharge Piping {toc}
+
+### The sump discharge piping shall include a check valve to prevent the discharged column of water from returning to the pit when the pump stops.
+
+### The check valve type shall be as indicated in the datasheet.
+
+```datasheet
+label: Sump Discharge Check Valve
+type: radio
+options:
+ - "Swing check valve"
+ - "Spring-loaded silent check valve"
+ - "Ball check valve"
+```
+
+### A swing check closes on reverse flow, so the returning column has already accelerated when the disc seats, which is the source of the pipe shock heard on pump shutdown. {note}
+
+### The check valve shall be installed in the orientation the valve manufacturer publishes for the pipe configuration in which it is used.
+
+### The check valve shall be reachable for service without cutting the discharge piping.
+
+### The sump discharge piping shall include a union or other dismantling connection to permit removal of the pump without cutting the discharge piping.
+
+### Where the discharge piping passes through a zone subject to freezing, it shall be insulated, heat-traced, or routed below the local frost depth.
+
+# Delivery, Storage, and Handling {toc}
+
+## Pipe, fittings, geotextiles, and drainage composites shall be delivered in the manufacturer's original packaging with labels intact.
+
+## Geotextiles and drainage composites shall be stored off the ground and under an opaque cover until installation.
+
+## The exposure of geotextiles and drainage composites to sunlight between removal from packaging and covering shall not exceed the period indicated in the datasheet.
+
+```datasheet
+label: Geotextile and Composite - Maximum Exposure Before Covering
+type: range
+unit: days
+min: 3
+max: 30
+setpoints: [3, 7, 14, 30]
+default: 14
+```
+
+## Ultraviolet exposure reduces the tensile and puncture strength of polymer geotextiles, and the loss is not visible on inspection. {note}
+
+## Drainage aggregate shall be stockpiled on a clean surface and shall be protected from contamination by soil, mud tracked from haul routes, and site runoff.
+
+## Aggregate that has been contaminated after delivery shall be rejected or rewashed and retested before placement.
+
+## Thermoplastic pipe shall be supported over its full length during storage and shall not be stored in a manner that produces sustained deflection.
+
+# Trench Excavation and Pipe Installation {toc}
+
+## The perimeter drain trench shall be excavated to a continuous fall from the high point of the run to the outlet or the sump pit.
+
+## The trench bottom shall be free of rock, debris, and protrusions that would create high points in the pipe alignment.
+
+## Soft, organic, or saturated trench bottom material shall be over-excavated and replaced with compacted granular fill before the drainage envelope is placed.
+
+## The perimeter drain pipe shall be installed to the alignment and invert elevations shown, [[drawing: perimeter drain alignment and inverts]].
+
+## Pipe joints shall be made with the pipe manufacturer's couplings or fittings.
+
+## Field-cut pipe ends shall be deburred and cleaned before assembly.
+
+## Tape, plastic sheeting, and other field-improvised joint wraps shall not be used at pipe joints.
+
+## Pipe slope shall be continuous from the high point to the outlet, without sag or reverse fall.
+
+## The installer shall verify slope with a level or laser at intervals not exceeding 10 ft and shall correct any sag before the aggregate envelope is placed.
+
+## A sag deep enough to hold standing water is a settling basin, and once it has accumulated sediment through the first few inflow events it does not clear itself. {note}
+
+## Changes in direction shall be made with manufactured fittings.
+
+## Field-cut miters and notched pipe shall not be used to make a change in direction.
+
+## Changes in direction of 90 degrees shall be made with two 45-degree fittings separated by a straight pipe section.
+
+## Two 45-degree fittings hold more flow capacity through the turn than a single 90-degree elbow and leave a rodding path a cleanout cable can follow. {note}
+
+## Cleanouts {toc}
+
+### A cleanout shall be provided at each of the locations indicated in the datasheet.
+
+```datasheet
+label: Cleanout Locations Required
+type: checkbox
+options:
+ - "High point of every drain run"
+ - "Every change of direction greater than 45 degrees"
+ - "Each building corner"
+ - "At the maximum spacing along straight runs"
+ - "At the sump pit connection"
+default:
+ - "High point of every drain run"
+ - "Every change of direction greater than 45 degrees"
+ - "At the maximum spacing along straight runs"
+ - "At the sump pit connection"
+```
+
+### The maximum cleanout spacing along straight runs shall be as indicated in the datasheet.
+
+```datasheet
+label: Cleanout - Maximum Spacing Along Straight Runs
+type: range
+unit: ft
+min: 50
+max: 200
+setpoints: [50, 75, 100, 150, 200]
+default: 100
+```
+
+### Each cleanout shall extend to finished grade or to an accessible interior location and shall be fitted with a removable cover.
+
+### Cleanout covers shall be set flush with finished grade and shall not be buried by landscaping, paving, or final grading.
+
+### A drain with no reachable cleanout cannot be flushed or camera-inspected, so the sediment it accumulates is permanent. {note}
+
+# Aggregate Envelope and Geotextile Placement {toc}
+
+## The geotextile shall be placed against the trench wall and the trench bottom before any envelope aggregate is placed, so that the completed envelope is fully enclosed and no soil contacts the envelope aggregate at any point.
+
+## The aggregate bedding shall be placed and shaped to the specified thickness before the pipe is set.
+
+## Envelope aggregate shall be placed evenly around and over the pipe to the specified cover thickness.
+
+## Envelope aggregate shall be placed by hand or by light equipment in a manner that does not displace the pipe from its set alignment and slope.
+
+## Aggregate discharged directly from a loader bucket onto unsupported pipe moves the pipe off line, opens joints, and can split the pipe wall. {note}
+
+## The installer shall re-verify pipe alignment and slope after envelope placement and before the geotextile is closed over the envelope.
+
+## Geotextile seams shall be overlapped not less than the dimension indicated in the datasheet.
+
+```datasheet
+label: Envelope Geotextile - Minimum Seam Overlap
+type: range
+unit: in
+min: 12
+max: 36
+setpoints: [12, 18, 24, 36]
+default: 12
+```
+
+## Geotextile seams shall be lapped so that the upper sheet sheds water away from the building face.
+
+## The geotextile shall be continuous over the full length of the perimeter drain.
+
+## The geotextile shall be lapped closed over the top of the completed envelope before backfill is placed.
+
+## The top lap shall be held in position until the first backfill lift is placed against it.
+
+## Torn or punctured geotextile shall be repaired with a patch of the same material lapped not less than the specified seam overlap on all sides, or the affected sheet shall be replaced.
+
+# Wall Drainage Composite Installation {toc}
+
+## The wall drainage composite shall be installed after the waterproofing membrane has cured, after the membrane has passed the field testing required by [[sync/below-grade-waterproofing]], and after the protection course required by the waterproofing manufacturer has been installed.
+
+## Composite installed over an untested membrane conceals any membrane defect beneath it, and neither the defect nor its location can be found afterward without removing the composite. {note}
+
+## The wall drainage composite shall be installed before backfill is placed against the wall.
+
+## The composite shall be installed with the core against the wall or the protection course and the geotextile face toward the soil.
+
+## Adjacent composite panels shall be lapped so that the geotextile of one panel covers the core of the adjacent panel across the full height of the seam.
+
+## The bottom edge of the composite shall be terminated as specified before the envelope geotextile is lapped closed over the aggregate envelope.
+
+## The envelope geotextile shall then be closed over the intersection of the composite and the envelope.
+
+## The geotextile face of the composite shall extend above the top edge of the core at the top termination and shall be sealed to the wall.
+
+## Backfill shall not be placed against the composite by dropping material directly onto the panel from height.
+
+# Testing and Verification {toc}
+
+## Perimeter Drain Verification {toc}
+
+### The perimeter drain shall be verified by the method or methods indicated in the datasheet after pipe and envelope placement and before final backfill.
+
+```datasheet
+label: Perimeter Drain Verification Method
+type: checkbox
+options:
+ - "Water introduction at the high-point cleanout with observation at the outlet"
+ - "Closed-circuit camera inspection of the full pipe length"
+default: "Water introduction at the high-point cleanout with observation at the outlet"
+```
+
+### Where water introduction is used, the Contractor shall introduce clean water at the high-point cleanout at not less than the rate indicated in the datasheet.
+
+```datasheet
+label: Perimeter Drain Verification - Minimum Water Introduction Rate
+type: range
+unit: gpm
+min: 5
+max: 100
+setpoints: [5, 10, 15, 25, 50, 100]
+```
+
+### Continuous discharge shall appear at the outlet within the elapsed time indicated in the datasheet, measured from the start of water introduction.
+
+```datasheet
+label: Perimeter Drain Verification - Maximum Time to Continuous Discharge
+type: range
+unit: min
+min: 2
+max: 30
+setpoints: [2, 5, 10, 15, 30]
+```
+
+### The Contractor shall record the elapsed time to first discharge, the observed discharge rate, and any surface ponding along the pipe alignment.
+
+### Where continuous discharge does not appear within the specified time, or where the observed discharge rate is materially below the introduction rate, the Contractor shall camera-inspect the run, correct the obstruction, and repeat the verification.
+
+### The cost of correcting a failed verification and of every repeat verification following a failure shall be borne by the Contractor.
+
+### Where the Contractor and the Engineer of Record disagree whether an observed discharge rate is materially below the introduction rate, the Engineer of Record shall make the initial determination.
+
+## Sump Pump Verification {toc}
+
+### The sump pump shall be exercised through not less than the number of on-off cycles indicated in the datasheet, using clean water introduced to the pit.
+
+```datasheet
+label: Sump Pump Verification - Minimum On-Off Cycles
+type: range
+unit: cycles
+min: 3
+max: 10
+setpoints: [3, 5, 10]
+default: 3
+```
+
+### The Contractor shall verify each item indicated in the datasheet during the sump pump verification.
+
+```datasheet
+label: Sump Pump Verification - Items Required
+type: checkbox
+options:
+ - "Pump-on float setpoint"
+ - "Pump-off float setpoint"
+ - "High-water alarm float setpoint"
+ - "Local audible and visual alarm"
+ - "Remote alarm annunciation"
+ - "Check valve holds against backflow into the pit"
+ - "Discharge piping watertight at all joints"
+ - "Operation on standby power"
+default:
+ - "Pump-on float setpoint"
+ - "Pump-off float setpoint"
+ - "High-water alarm float setpoint"
+ - "Local audible and visual alarm"
+ - "Check valve holds against backflow into the pit"
+ - "Discharge piping watertight at all joints"
+```
+
+### Float setpoints as left at the end of the verification shall be recorded in the start-up report.
+
+## Visual Inspection Before Backfill {toc}
+
+### The perimeter drain, aggregate envelope, and geotextile shall be visually inspected before backfill begins.
+
+### The inspection shall confirm pipe alignment and slope, envelope bedding and cover thickness, envelope extension beyond the footing, continuous geotextile coverage with the specified seam overlap, cleanout locations, and the bottom termination of the wall drainage composite where one is provided.
+
+### Deficiencies found at the inspection shall be corrected and re-inspected before backfill is placed.
+
+# Cleaning and Final Acceptance {toc}
+
+## After the perimeter drain verification is complete, the Contractor shall flush the drain with clean water at each cleanout to remove construction sediment.
+
+## The Contractor shall confirm that the outlet is clear of debris and that the outlet screen is in place and secured.
+
+## The Contractor shall confirm that every cleanout cover is exposed and operable at finished grade after final grading and landscaping are complete.
+
+## Final acceptance of the foundation drainage system shall be contingent on a passing perimeter drain verification, a passing sump pump verification where a sump is provided, and receipt of the closeout submittals listed in this standard.
+
+# Warranty {toc}
+
+## The Contractor shall warrant the foundation drainage installation against defective materials and workmanship for the period indicated in the datasheet, measured from the date of Substantial Completion.
+
+```datasheet
+label: Foundation Drainage Installation Warranty Period
+type: range
+unit: yr
+min: 1
+max: 5
+setpoints: [1, 2, 3, 5]
+default: 1
+```
+
+## The Contractor shall provide the sump pump, control, and check valve manufacturers' written warranties, made out to the Owner, for the period indicated in the datasheet, measured from the date of Substantial Completion.
+
+```datasheet
+label: Sump Pump and Controls Warranty Period
+type: range
+unit: yr
+min: 1
+max: 5
+setpoints: [1, 2, 3, 5]
+default: 1
+```
+
+## A repair made under warranty shall itself be warranted for a fresh full warranty term from the date the repair is completed, or for the remainder of the original term, whichever ends later.
+
+## The Contractor shall bear the cost of excavation, removal and replacement of backfill, paving, and landscaping required to reach and repair warranted work, and shall restore the disturbed area to the condition documented in the pre-existing condition survey.
+
+## The Contractor shall document the pre-existing condition of any area that would have to be disturbed to reach the foundation drainage system, before that area is covered.
+
+## Restoration obligations that reference an existing condition are unenforceable without a documented baseline recorded before the work was covered, which is why the survey is required rather than recommended. {note}
+
+# Spare Parts and Maintenance Materials {toc}
+
+## The Contractor shall deliver to the Owner the spare parts indicated in the datasheet before the date of Substantial Completion.
+
+```datasheet
+label: Spare Parts and Maintenance Materials
+type: checkbox
+options:
+ - "One spare sump pump of each type and capacity installed"
+ - "One spare float switch set for each pump control arrangement"
+ - "One spare check valve of each type and size installed"
+ - "Two spare cleanout covers of each type and size installed"
+ - "One spare battery for each battery-backed pump"
+default:
+ - "One spare float switch set for each pump control arrangement"
+ - "Two spare cleanout covers of each type and size installed"
+```
+
+## Spare parts shall be delivered in the manufacturer's original packaging and shall be stored where the Owner directs.
+
+## The Contractor shall record the delivered spare parts, with manufacturer and model designation, in the operation and maintenance manual.