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SynC · SynC Standards

Foundation Drainage

Rev5
IssuedAug 29, 2026
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1 Scope

NOTE This standard governs the design basis, materials, installation, and field verification of foundation drainage systems serving below-grade structures. (1.1)
NOTE The system covered by this standard comprises the components listed below. (1.2)
  • 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
NOTE Foundation drainage and below-grade waterproofing perform different functions within the same assembly. (1.3)
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. (1.4)
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. (1.5)
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. (1.6)
NOTE Requirements for the waterproofing membrane, its field testing, and its protection course are governed by Below Grade WaterproofingBelow-Grade WaterproofingResolves to the current adopted revision.sync/below-grade-waterproofing and are outside this scope. (1.7)
NOTE Excavation, backfill placement, and compaction are governed by EarthworkEarthworkResolves to the current adopted revision.sync/earthwork, and the storm drainage system downstream of the outlet connection is governed by Storm DrainageStorm DrainageResolves to the current adopted revision.sync/storm-drainage. (1.8)

2 Referenced Standards

2.1 Materials, testing, and installation shall comply with the latest adopted edition of each of the following unless a specific edition is cited.
2.2 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

3 Submittals

3.1 Action Submittals

3.1.1 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
Action Submittals Requiredcheckbox
☑ 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
3.1.2 The aggregate gradation report shall be dated not more than 6 months before the date of the delivery it represents.
3.1.3 No portion of the foundation drainage installation shall proceed until the action submittals covering that portion have been reviewed and returned.

3.2 Closeout Submittals

3.2.1 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
Closeout Submittals Requiredcheckbox
☑ 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

4 Quality Assurance

4.1 Installer Qualifications

4.1.1 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.
4.1.2 Sump pump piping and electrical connections shall be performed by subcontractors licensed for that work where the Authority Having Jurisdiction requires a license.

4.2 Pre-Installation Conference

4.2.1 A pre-installation conference shall be held at the site before foundation drainage installation begins.
4.2.2 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.
4.2.3 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.
4.2.4 Minutes shall be recorded by the General Contractor and distributed to all attendees within 5 working days.

4.3 Inspection Before Concealment

4.3.1 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.
4.3.2 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.
4.3.3 Work concealed before the required inspection shall be uncovered at the Contractor's cost and reinstated after inspection.

5 Design Groundwater Basis

5.1 The Engineer of Record shall establish the design groundwater elevation and the seasonal high water table elevation from a site-specific geotechnical investigation.
5.2 The foundation drainage system shall be designed for the seasonal high water table elevation rather than the average groundwater elevation.
NOTE 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. (5.3)
5.4 The design groundwater condition shall be as indicated in the datasheet and shall be the same condition used for the Below Grade WaterproofingBelow-Grade WaterproofingResolves to the current adopted revision.sync/below-grade-waterproofing scope.
Design Groundwater Conditionradio
○ Non-hydrostatic
○ Intermittently hydrostatic
○ Continuously hydrostatic
Per drawings — geotechnical investigation report (deferred by default)
NOTE The three design groundwater conditions are distinguished by where the seasonal high water table stands relative to the below-grade assembly. (5.5)
  • 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
5.6 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.
5.7 Where the design groundwater condition is continuously hydrostatic, a sub-slab drainage layer with collector piping shall be provided beneath slabs on grade.
5.8 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.

6 Discharge Conveyance and Outlet

6.1 Water collected by the foundation drainage system shall be conveyed to an approved outlet by the conveyance method indicated in the datasheet.
Discharge Conveyance Methodradio
○ Gravity throughout
○ Pumped from a sump pit
Per drawings — civil grading plan and foundation plan (deferred by default)
NOTE 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. (6.2)
6.3 The discharge destination shall be as indicated in the datasheet.
Discharge Destinationradio
○ Daylight outlet
○ Storm drainage system
○ Dry well or other infiltration structure
Per drawings — civil grading plan (deferred by default)
6.4 Foundation drainage shall not be discharged to a sanitary sewer.
6.5 The Contractor shall confirm the permitted discharge destination with the Authority Having Jurisdiction before procuring sump, pump, or outlet materials.
6.6 Where the Authority Having Jurisdiction prohibits the discharge destination indicated in the datasheet, the Contractor shall notify the Engineer of Record before proceeding.

6.7 Daylight Outlet

6.7.1 The daylight outlet shall be located so that discharged water flows away from the foundation and does not return toward the building.
6.7.2 The daylight outlet shall be located not less than the horizontal distance indicated in the datasheet from the outside face of the foundation wall.
Daylight Outlet - Minimum Horizontal Distance from Foundationrange
ft
51015203050
Per drawings — civil grading plan (deferred by default)
6.7.3 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.
6.7.4 The daylight outlet shall be fitted with a rodent and debris screen that can be removed for cleaning without excavation.
6.7.5 The daylight outlet shall be located where it can be seen and reached for inspection after final grading and landscaping are complete.
6.7.6 Freeze protection of the daylight outlet shall be as indicated in the datasheet.
Daylight Outlet - Freeze Protectionradio
○ Outlet invert located below the local frost depth
○ Insulated and heat-traced outlet riser
○ No freeze protection provided
○ Not applicable - no daylight outlet
6.7.7 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.
NOTE 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. (6.7.8)

6.8 Storm Drainage Connection

6.8.1 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.
6.8.2 The invert of the connection shall be above the design hydraulic grade line of the storm drainage system at the point of connection.
NOTE A connection below the storm system's hydraulic grade line is backflooded during the storm events the foundation drain exists to survive. (6.8.3)
6.8.4 The connection detail and the receiving structure shall be coordinated with Storm DrainageStorm DrainageResolves to the current adopted revision.sync/storm-drainage.

6.9 Dry Well and Infiltration Outlets

6.9.1 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.
6.9.2 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.
NOTE An infiltration structure that cannot drain becomes a standing reservoir near the foundation rather than an outlet. (6.9.3)

7 Perimeter Drain Pipe

7.1 The perimeter drain pipe shall be a perforated thermoplastic pipe of the type indicated in the datasheet.
Perimeter Drain Pipe Typeradio
○ 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
NOTE 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. (7.2)
7.3 The nominal pipe diameter shall be as indicated in the datasheet.
Perimeter Drain Pipe - Nominal Diameterrange
in
4681012
Per drawings — foundation plan and drainage profile (deferred by default)
7.4 The pipe diameter shall be sized by the Engineer of Record for the design flow, the total run length, and the available slope.
NOTE 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. (7.5)
7.6 The minimum pipe slope shall be as indicated in the datasheet and shall account for the interior friction loss of the pipe type selected.
Perimeter Drain Pipe - Minimum Sloperange
%
0.50.7511.5235
NOTE 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. (7.7)
7.8 The minimum pipe stiffness at 5 percent deflection when tested in accordance with ASTM D2412 shall be as indicated in the datasheet.
Perimeter Drain Pipe - Minimum Pipe Stiffness at 5 Percent Deflectionrange
psi
283546115
7.9 Pipe stiffness shall be selected for the depth of cover and the construction loading the pipe will carry before and after backfill.

7.10 Perforations

7.10.1 The perforation pattern shall be as indicated in the datasheet.
Drain Pipe Perforation Patternradio
○ Circular perforations arrayed in rows
○ Longitudinal slots
Manufacturer's standard (by default)
7.10.2 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.
7.10.3 The manufacturer shall report the perforation pattern and the perforation opening dimension in the action submittals.
NOTE 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. (7.10.4)
7.10.5 The perforation orientation shall be as indicated in the datasheet.
Drain Pipe Perforation Orientationradio
● Perforations down
○ Perforations up
NOTE 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. (7.10.6)
7.10.7 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.

7.11 Pipe Wrap

7.11.1 The pipe wrap shall be as indicated in the datasheet.
Perimeter Drain Pipe - Pipe Wrapradio
○ Factory-applied circular-knit geotextile sock conforming to ASTM D6707
○ Factory-applied nonwoven geotextile sock
○ No pipe wrap
7.11.2 A pipe wrap shall not be substituted for the aggregate envelope or for the envelope geotextile.
NOTE 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. (7.11.3)

8 Drainage Aggregate Envelope

8.1 The drainage aggregate envelope shall be a washed, open-graded crushed stone or gravel of the gradation indicated in the datasheet.
Drainage Envelope Aggregate Gradationradio
○ ASTM D448 No. 4
● ASTM D448 No. 57
○ ASTM D448 No. 6
○ ASTM D448 No. 67
○ ASTM D448 No. 8
8.2 The envelope aggregate shall contain not more than 10 percent material passing the No. 4 sieve, as required by IBC Section 1805.4.1.
8.3 The envelope aggregate shall be washed at the source.
8.4 The percent of envelope aggregate passing the No. 200 sieve shall not exceed the value indicated in the datasheet.
Envelope Aggregate - Maximum Material Passing the No. 200 Sieverange
%
0.51235
8.5 Unwashed pit-run stone shall not be placed in the drainage envelope even where its size gradation falls within the specified envelope.
NOTE 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. (8.6)

8.7 Envelope Dimensions

8.7.1 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.
Drainage Envelope - Aggregate Bedding Below Piperange
in
246812
Per drawings — foundation sections and drainage details (deferred by default)
8.7.2 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.
Drainage Envelope - Aggregate Cover Over Piperange
in
68121824
Per drawings — foundation sections and drainage details (deferred by default)
8.7.3 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.
Drainage Envelope - Extension Beyond Outside Edge of Footingrange
in
12182436
Per drawings — foundation sections and drainage details (deferred by default)
8.7.4 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.
NOTE 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. (8.7.5)

9 Envelope Geotextile

9.1 A geotextile shall be installed between the drainage aggregate envelope and the adjacent soil or backfill on all sides of the envelope.
9.2 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.
NOTE 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. (9.3)
9.4 The geotextile type shall be as indicated in the datasheet.
Envelope Geotextile Typeradio
● Nonwoven needle-punched geotextile
○ Woven monofilament geotextile
9.5 Woven slit-film geotextiles shall not be used in subsurface drainage applications, in accordance with AASHTO M288.
9.6 The geotextile strength class per AASHTO M288 shall be as indicated in the datasheet.
Envelope Geotextile - Strength Class per AASHTO M288select
Class 1
Class 2
Class 3
NOTE AASHTO M288 selects the strength class from the severity of installation stress, and Class 2 is its default class for subsurface drainage. (9.7)

9.8 Filtration Properties

9.8.1 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.
Envelope Geotextile - Maximum Apparent Opening Size per ASTM D4751range
mm
0.150.180.220.250.30.430.6
Envelope Geotextile - Minimum Permittivity per ASTM D4491range
1/s
0.10.20.511.52
NOTE 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. (9.8.2)
9.8.3 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.

9.9 Filtration Compatibility Evaluation

9.9.1 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.
Soil-Geotextile Filtration Compatibility Evaluation per ASTM D5101radio
○ Required
○ Not required
NOTE 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. (9.9.2)
9.9.3 Where the evaluation is required, the measured gradient ratio shall not exceed the value indicated in the datasheet.
Soil-Geotextile - Maximum Gradient Ratio per ASTM D5101range
11.522.53
9.9.4 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.

10 Below-Grade Wall Drainage

10.1 Provision of a prefabricated drainage composite over below-grade walls shall be as indicated in the datasheet.
Wall Drainage Compositeradio
○ Provided over the waterproofed wall face
○ Not provided
NOTE 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. (10.2)
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. (10.3)
10.4 Backfill against below-grade walls shall be as indicated in the datasheet.
Backfill Against Below-Grade Wallsradio
○ Free-draining granular backfill
○ Site-excavated backfill placed per the earthwork requirements
Per drawings — foundation sections (deferred by default)
NOTE 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. (10.5)
NOTE Backfill material, lift thickness, and compaction are governed by EarthworkEarthworkResolves to the current adopted revision.sync/earthwork. (10.6)

10.7 Composite Core and Flow Capacity

10.7.1 The minimum core thickness of the wall drainage composite shall be as indicated in the datasheet.
Wall Drainage Composite - Minimum Core Thicknessrange
in
0.250.3750.50.6251
10.7.2 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.
Wall Drainage Composite - Minimum In-Plane Flow Rate per ASTM D4716range
gpm/ft
125101525
10.7.3 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.
NOTE 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. (10.7.4)
10.7.5 Whether compressive creep testing per ASTM D7140 is required shall be as indicated in the datasheet.
Wall Drainage Composite - Compressive Creep Testing per ASTM D7140radio
○ Required
○ Not required
NOTE 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. (10.7.6)

10.8 Composite Geotextile Face

10.8.1 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.
10.8.2 The Contractor shall confirm the compatibility of the composite manufacturer's laminated geotextile with the backfill soil before the composite is ordered.
NOTE The laminated geotextile is fixed when the composite is manufactured and cannot be exchanged in the field. (10.8.3)

10.9 Composite Attachment and Terminations

10.9.1 The attachment method for the wall drainage composite shall be as indicated in the datasheet.
Wall Drainage Composite - Attachment Methodradio
○ Adhesive applied to the wall face
○ Mastic tabs
○ Termination bar at the top edge with the panel hanging free below
Manufacturer's standard (by default)
10.9.2 Fasteners that penetrate the waterproofing membrane shall not be used to attach the wall drainage composite.
10.9.3 The attachment method shall be one that both the waterproofing manufacturer and the composite manufacturer accept for use with each other's product.
10.9.4 The bottom termination of the wall drainage composite shall be as indicated in the datasheet.
Wall Drainage Composite - Bottom Terminationradio
● Terminated within the perimeter drain aggregate envelope beneath the envelope geotextile
○ Terminated at the top of the perimeter drain aggregate envelope
NOTE 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. (10.9.5)
10.9.6 The top termination of the wall drainage composite shall be as indicated in the datasheet.
Wall Drainage Composite - Top Terminationradio
○ 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
Manufacturer's standard (by default)
10.9.7 The top termination shall close the top of the core against the entry of soil, root material, and debris.

11 Sub-Slab Drainage

11.1 Provision of a sub-slab drainage layer beneath slabs on grade shall be as indicated in the datasheet.
Sub-Slab Drainage Layerradio
○ Provided beneath slabs on grade
○ Not provided
NOTE 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. (11.2)
11.3 The thickness of the sub-slab drainage layer shall be as indicated in the datasheet.
Sub-Slab Drainage Layer - Thicknessrange
in
4681012
Per drawings — foundation plan and slab sections (deferred by default)
11.4 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.
11.5 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.
NOTE 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. (11.6)
11.7 The sub-slab drainage layer shall be connected to the perimeter drain or to the sump pit at the slab edge.
11.8 Provision of collector piping within the sub-slab drainage layer shall be as indicated in the datasheet.
Sub-Slab Collector Pipingradio
○ Provided within the sub-slab drainage layer
○ Not provided
11.9 The maximum spacing of sub-slab collector piping shall be as indicated in the datasheet.
Sub-Slab Collector Piping - Maximum Spacingrange
ft
10152025304050100
Per drawings — foundation plan (deferred by default)
NOTE 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. (11.10)
11.11 Where an underslab waterproofing membrane is specified, the sub-slab drainage layer shall be placed beneath that membrane.
11.12 The interface between the sub-slab drainage scope and the underslab waterproofing scope shall be reviewed at the pre-installation conference and coordinated with Below Grade WaterproofingBelow-Grade WaterproofingResolves to the current adopted revision.sync/below-grade-waterproofing.

12 Crawl Space Drainage

12.1 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.
12.2 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.
12.3 The crawl space ground surface shall be graded to fall toward the sump pit or the interior drain inlet.
12.4 Access shall be provided to the crawl space sump, its controls, and the perimeter drain cleanouts for periodic inspection.
NOTE The crawl space vapor retarder is governed by the project's vapor retarder scope and is not part of the drainage scope. (12.5)

13 Sump Pit and Pump Assembly

13.1 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.
13.2 The minimum interior diameter of the sump pit shall be as indicated in the datasheet.
Sump Pit - Minimum Interior Diameterrange
in
182430364860
Per drawings — foundation plan and sump pit detail (deferred by default)
NOTE 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. (13.3)
13.4 The sump pit material shall be as indicated in the datasheet.
Sump Pit Materialselect
Structural thermoplastic
Fiberglass-reinforced polyester
Precast concrete
13.5 The sump pit cover shall be as indicated in the datasheet.
Sump Pit Coverselect
Gasketed and mechanically fastened cover sealed for soil-gas control
Solid unsealed cover
Slotted or grated cover
NOTE An open or slotted pit within a conditioned or occupied below-grade space is a continuous path between the soil and the interior air. (13.6)

13.7 Pump Configuration and Standby Power

13.7.1 The sump pump configuration shall be as indicated in the datasheet.
Sump Pump Configurationradio
○ Simplex
○ Duplex with alternating duty
○ Simplex with a battery-backed secondary pump
13.7.2 The design discharge capacity of the sump pump shall be as indicated in the datasheet.
Sump Pump - Design Discharge Capacityrange
gpm
10500
Per drawings — pump schedule (deferred by default)
13.7.3 Sump pumps shall be listed to UL 778.
13.7.4 The standby power arrangement for the sump pump shall be as indicated in the datasheet.
Sump Pump - Standby Power Arrangementradio
○ Battery-backed inverter dedicated to the sump
○ Building standby generator branch circuit
○ No standby power provided
NOTE 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. (13.7.5)
13.7.6 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.
13.7.7 Sump pump branch circuits, disconnects, and receptacles shall comply with NFPA 70.

13.8 High-Water Alarm

13.8.1 A high-water alarm float independent of the pump control floats shall be provided in every sump pit.
13.8.2 The alarm annunciation shall be as indicated in the datasheet.
High-Water Alarm Annunciationradio
● 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
13.8.3 The high-water alarm shall remain powered when the pump branch circuit is de-energized.
NOTE An alarm that shares the circuit it is watching goes silent for the failure it exists to report. (13.8.4)

13.9 Sump Discharge Piping

13.9.1 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.
13.9.2 The check valve type shall be as indicated in the datasheet.
Sump Discharge Check Valveradio
○ Swing check valve
○ Spring-loaded silent check valve
○ Ball check valve
NOTE 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. (13.9.3)
13.9.4 The check valve shall be installed in the orientation the valve manufacturer publishes for the pipe configuration in which it is used.
13.9.5 The check valve shall be reachable for service without cutting the discharge piping.
13.9.6 The sump discharge piping shall include a union or other dismantling connection to permit removal of the pump without cutting the discharge piping.
13.9.7 Where the discharge piping passes through a zone subject to freezing, it shall be insulated, heat-traced, or routed below the local frost depth.

14 Delivery, Storage, and Handling

14.1 Pipe, fittings, geotextiles, and drainage composites shall be delivered in the manufacturer's original packaging with labels intact.
14.2 Geotextiles and drainage composites shall be stored off the ground and under an opaque cover until installation.
14.3 The exposure of geotextiles and drainage composites to sunlight between removal from packaging and covering shall not exceed the period indicated in the datasheet.
Geotextile and Composite - Maximum Exposure Before Coveringrange
days
371430
NOTE Ultraviolet exposure reduces the tensile and puncture strength of polymer geotextiles, and the loss is not visible on inspection. (14.4)
14.5 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.
14.6 Aggregate that has been contaminated after delivery shall be rejected or rewashed and retested before placement.
14.7 Thermoplastic pipe shall be supported over its full length during storage and shall not be stored in a manner that produces sustained deflection.

15 Trench Excavation and Pipe Installation

15.1 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.
15.2 The trench bottom shall be free of rock, debris, and protrusions that would create high points in the pipe alignment.
15.3 Soft, organic, or saturated trench bottom material shall be over-excavated and replaced with compacted granular fill before the drainage envelope is placed.
15.4 The perimeter drain pipe shall be installed to the alignment and invert elevations shown, perimeter drain alignment and inverts.
15.5 Pipe joints shall be made with the pipe manufacturer's couplings or fittings.
15.6 Field-cut pipe ends shall be deburred and cleaned before assembly.
15.7 Tape, plastic sheeting, and other field-improvised joint wraps shall not be used at pipe joints.
15.8 Pipe slope shall be continuous from the high point to the outlet, without sag or reverse fall.
15.9 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.
NOTE 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. (15.10)
15.11 Changes in direction shall be made with manufactured fittings.
15.12 Field-cut miters and notched pipe shall not be used to make a change in direction.
15.13 Changes in direction of 90 degrees shall be made with two 45-degree fittings separated by a straight pipe section.
NOTE 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. (15.14)

15.15 Cleanouts

15.15.1 A cleanout shall be provided at each of the locations indicated in the datasheet.
Cleanout Locations Requiredcheckbox
☑ 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
15.15.2 The maximum cleanout spacing along straight runs shall be as indicated in the datasheet.
Cleanout - Maximum Spacing Along Straight Runsrange
ft
5075100150200
15.15.3 Each cleanout shall extend to finished grade or to an accessible interior location and shall be fitted with a removable cover.
15.15.4 Cleanout covers shall be set flush with finished grade and shall not be buried by landscaping, paving, or final grading.
NOTE A drain with no reachable cleanout cannot be flushed or camera-inspected, so the sediment it accumulates is permanent. (15.15.5)

16 Aggregate Envelope and Geotextile Placement

16.1 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.
16.2 The aggregate bedding shall be placed and shaped to the specified thickness before the pipe is set.
16.3 Envelope aggregate shall be placed evenly around and over the pipe to the specified cover thickness.
16.4 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.
NOTE Aggregate discharged directly from a loader bucket onto unsupported pipe moves the pipe off line, opens joints, and can split the pipe wall. (16.5)
16.6 The installer shall re-verify pipe alignment and slope after envelope placement and before the geotextile is closed over the envelope.
16.7 Geotextile seams shall be overlapped not less than the dimension indicated in the datasheet.
Envelope Geotextile - Minimum Seam Overlaprange
in
12182436
16.8 Geotextile seams shall be lapped so that the upper sheet sheds water away from the building face.
16.9 The geotextile shall be continuous over the full length of the perimeter drain.
16.10 The geotextile shall be lapped closed over the top of the completed envelope before backfill is placed.
16.11 The top lap shall be held in position until the first backfill lift is placed against it.
16.12 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.

17 Wall Drainage Composite Installation

17.1 The wall drainage composite shall be installed after the waterproofing membrane has cured, after the membrane has passed the field testing required by Below Grade WaterproofingBelow-Grade WaterproofingResolves to the current adopted revision.sync/below-grade-waterproofing, and after the protection course required by the waterproofing manufacturer has been installed.
NOTE 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. (17.2)
17.3 The wall drainage composite shall be installed before backfill is placed against the wall.
17.4 The composite shall be installed with the core against the wall or the protection course and the geotextile face toward the soil.
17.5 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.
17.6 The bottom edge of the composite shall be terminated as specified before the envelope geotextile is lapped closed over the aggregate envelope.
17.7 The envelope geotextile shall then be closed over the intersection of the composite and the envelope.
17.8 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.
17.9 Backfill shall not be placed against the composite by dropping material directly onto the panel from height.

18 Testing and Verification

18.1 Perimeter Drain Verification

18.1.1 The perimeter drain shall be verified by the method or methods indicated in the datasheet after pipe and envelope placement and before final backfill.
Perimeter Drain Verification Methodcheckbox
☑ Water introduction at the high-point cleanout with observation at the outlet
☐ Closed-circuit camera inspection of the full pipe length
18.1.2 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.
Perimeter Drain Verification - Minimum Water Introduction Raterange
gpm
510152550100
18.1.3 Continuous discharge shall appear at the outlet within the elapsed time indicated in the datasheet, measured from the start of water introduction.
Perimeter Drain Verification - Maximum Time to Continuous Dischargerange
min
25101530
18.1.4 The Contractor shall record the elapsed time to first discharge, the observed discharge rate, and any surface ponding along the pipe alignment.
18.1.5 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.
18.1.6 The cost of correcting a failed verification and of every repeat verification following a failure shall be borne by the Contractor.
18.1.7 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.

18.2 Sump Pump Verification

18.2.1 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.
Sump Pump Verification - Minimum On-Off Cyclesrange
cycles
3510
18.2.2 The Contractor shall verify each item indicated in the datasheet during the sump pump verification.
Sump Pump Verification - Items Requiredcheckbox
☑ 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
18.2.3 Float setpoints as left at the end of the verification shall be recorded in the start-up report.

18.3 Visual Inspection Before Backfill

18.3.1 The perimeter drain, aggregate envelope, and geotextile shall be visually inspected before backfill begins.
18.3.2 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.
18.3.3 Deficiencies found at the inspection shall be corrected and re-inspected before backfill is placed.

19 Cleaning and Final Acceptance

19.1 After the perimeter drain verification is complete, the Contractor shall flush the drain with clean water at each cleanout to remove construction sediment.
19.2 The Contractor shall confirm that the outlet is clear of debris and that the outlet screen is in place and secured.
19.3 The Contractor shall confirm that every cleanout cover is exposed and operable at finished grade after final grading and landscaping are complete.
19.4 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.

20 Warranty

20.1 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.
Foundation Drainage Installation Warranty Periodrange
yr
1235
20.2 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.
Sump Pump and Controls Warranty Periodrange
yr
1235
20.3 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.
20.4 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.
20.5 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.

21 Spare Parts and Maintenance Materials

21.1 The Contractor shall deliver to the Owner the spare parts indicated in the datasheet before the date of Substantial Completion.
Spare Parts and Maintenance Materialscheckbox
☐ 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
21.2 Spare parts shall be delivered in the manufacturer's original packaging and shall be stored where the Owner directs.
21.3 The Contractor shall record the delivered spare parts, with manufacturer and model designation, in the operation and maintenance manual.

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