1 Scope

NOTE This standard covers floor drains and trench drains as assembled systems — the drain body, frame, grate or strainer, outlet, trap and trap primer, sediment bucket, and any integral waterproofing flange — for non-residential interior floors and immediately adjacent exterior areas. (1.1)

NOTE A floor drain is a point drain: a round or square body set flush with the floor, fitted with a removable strainer or grate, that collects water at a single low point. A trench drain is a linear drain: a continuous channel, typically pre-sloped, fitted with a removable grate, that collects water along a line. (1.2)

NOTE Drain bodies, channels, grates, and traps to the drain outlet are within scope. (1.4)

NOTE Sanitary waste and vent piping downstream of the drain outlet is not covered here; see Sanitary Waste And Vent PipingSanitary Waste and Vent PipingResolves to the current edition.sync/sanitary-waste-and-vent-piping. (1.5)

NOTE Roof drains, scuppers, and overflow inlets are not covered here; see Roof DrainageRoof DrainageResolves to the current edition.sync/roof-drainage. (1.6)

NOTE Gravity and hydromechanical grease interceptors installed in the drainage line are not covered here; see Grease InterceptorsGrease InterceptorsResolves to the current edition.sync/grease-interceptors. (1.7)

NOTE Cleanouts, backwater valves, and floor sinks beyond basic drain bodies are not covered here; see Plumbing SpecialtiesPlumbing SpecialtiesResolves to the current edition.sync/plumbing-specialties. (1.8)

NOTE Below-grade exterior perimeter, footing, and foundation drainage (French drains, foundation drains) is civil and waterproofing scope and is not covered here. (1.9)

2 Referenced Standards

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

2.2 Where the adopted plumbing code and a referenced product standard conflict, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.

NOTE As of the 2022 edition, floor drains and trench drains are covered by two separate harmonized ASME/CSA standards; the older combined ASME A112.6.3-2019 edition is still widely cited in practice but should be superseded in new specifications. (2.3)

Standard	Title
ASME A112.6.3 / CSA B79.3	Floor Drains (2022; floor drains, adjustable floor drains, area drains)
ASME A112.6.8 / CSA B79.8	Trench Drains (2022; trench drains, utility channels, grate systems)
ASME A112.3.1	Stainless Steel Drainage Fittings for Above-Ground Sanitary Drainage and Vent Piping Systems
ASME A112.21.1M	Floor Drains (legacy edition; superseded by A112.6.3 / CSA B79.3)
NSF/ANSI 2	Food Equipment
ADA Standards for Accessible Design (2010)	Accessible Design — Section 302.3 Openings
IPC	International Plumbing Code (Sections 411, 413, and 1002)
UPC	Uniform Plumbing Code (Chapter 4, Fixtures and Fittings)
EN 1433 (informative)	Drainage Channels for Vehicular and Pedestrian Areas — Load Classification (Classes A–F)

NOTE The load-class letters (A through F) used throughout manufacturers' literature derive from the European EN 1433 framework and are not formally defined in the ASME/CSA standards; where a load class letter is specified, the corresponding wheel/axle load and test category shall be stated so the requirement is unambiguous to a domestic supplier. (2.4)

3 Submittals

3.1 Action Submittals

3.1.1 The Contractor shall submit the following action submittals for each floor drain and trench drain type before fabrication or ordering:

Product data for each drain type, including body material, outlet size and orientation, trap configuration, and grate or strainer
Manufacturer's load-class rating and the corresponding wheel or axle load for each trench drain and area drain
NSF/ANSI 2 listing documentation for every drain in a food-service splash or food-contact zone
Shop drawings showing channel runs, slope, invert elevations, outlet locations, and required slab depressions or blockouts
Grate selection showing slot width, bearing-bar orientation, and ADA compliance for drains in accessible routes
Trap primer type, connection point, and (for electronic primers) the required electrical circuit
Drain schedule keyed to the floor plans, listing tag, location, load class, body and grate material, and outlet size

Action submittals providedcheckbox

☐ Product data (body, outlet, trap, grate/strainer)

☐ Load-class rating with wheel/axle load

☐ NSF/ANSI 2 listing for food-zone drains

☐ Shop drawings (runs, slope, inverts, outlets, depressions)

☐ Grate slot width and ADA-compliance documentation

☐ Trap primer type, connection, and electrical circuit

☐ Drain schedule keyed to floor plans

3.2 Informational Submittals

3.2.1 The Contractor shall submit the following informational submittals:

Manufacturer's installation instructions, including formwork, encasement, and grate-protection requirements
Material compatibility statement for the channel body and grate against the expected drainage fluid chemistry and temperature
Manufacturer's certification that grates in vehicular areas meet the specified load class per the cited test method

Informational submittals providedcheckbox

☐ Installation instructions (formwork, encasement, protection)

☐ Material/fluid compatibility statement

☐ Grate load-class certification

3.3 Closeout Submittals

3.3.1 The Contractor shall submit the following closeout submittals:

Operation and maintenance data, including sediment-bucket cleaning intervals and grate-removal instructions
Warranty documentation for the drain assemblies
Record drawings showing as-installed invert elevations and outlet connections

Closeout submittals providedcheckbox

☐ O&M data (sediment-bucket cleaning, grate removal)

☐ Warranty documentation

☐ Record drawings (as-installed inverts and outlets)

4 Quality Assurance

4.1 Floor drains shall be listed to ASME A112.6.3 / CSA B79.3.

4.2 Trench drains shall be listed to ASME A112.6.8 / CSA B79.8.

4.3 Stainless steel drain bodies used in above-ground sanitary drainage shall comply with ASME A112.3.1.

4.4 Drains in food-service splash and food-contact zones shall be NSF/ANSI 2 listed as complete assemblies, including body, strainer, and grate.

NOTE NSF/ANSI 2 listing governs the entire drain assembly, not just the body material; a generic stainless body without an assembly listing will satisfy the plumbing code but fail a health-department inspection. (4.4.1)

4.5 Grates installed within an accessible route shall comply with ADA Standards Section 302.3.

4.6 The manufacturer shall be a single source for the channel, frame, grate, and outlet of each trench drain system so that load rating and fit are warranted as an assembly.

NOTE A common specification error on post-2022 projects is to cite ASME A112.6.3-2019 by edition year for both device families; that combined edition was split, so the old number is ambiguous for a trench drain. Cite A112.6.3 / CSA B79.3 for floor drains and A112.6.8 / CSA B79.8 for trench drains. (4.6.1)

NOTE Mixing a channel from one system with a grate and frame from another voids the assembly's load certification and frequently produces a rocking or proud grate; single-source the load-bearing components. (4.6.2)

5 Environmental and Service Conditions

5.1 The drainage fluid chemistry, temperature, and solids content shall be identified for each area before the channel body and grate materials are selected.

NOTE Polymer concrete degrades in sustained high-pH or high-solvent exposure; auto shops, laboratories, and process floors with solvent or acid discharge require chemical-resistant HDPE or stainless steel rather than polymer concrete. (5.1.1)

NOTE Continuous hot discharge (commercial dishwashing, sterilizers, process blowdown) can soften some polymer bodies and grate coatings; confirm the body and grate are rated for the peak fluid temperature. (5.1.2)

5.2 The peak discharge temperature for each drain area shall be identified.

Peak drainage fluid temperaturerange

°C

1095

Default: 40 °C

5.3 The drainage fluid chemistry classification shall be selected for each area.

Drainage fluid chemistryselect

Clear water / stormwater

Domestic wastewater (kitchen, washdown)

Solvent or hydrocarbon exposure

Acid or alkaline (low/high pH) process discharge

Saltwater / brine / de-icing runoff

6 Load Classification

6.1 The load class shall be specified for every trench drain and area drain on the drain schedule; a drain schedule that omits load class shall be considered incomplete.

NOTE Contractors default to the lightest available grate when load class is absent; in a parking garage or loading dock that omission leads to grate failure under forklift or fire-apparatus loads. State the load class explicitly. (6.1.1)

NOTE The EN 1433 load classes provide a common vocabulary used in US manufacturers' literature: Class A (pedestrian/cycle), Class B (light vehicular, passenger cars), Class C (slow-moving light commercial), Class D (delivery trucks and most roadways), Class E (heavy industrial), and Class F (airport/extreme axle loads). Because these classes are not defined in the ASME standards, the corresponding wheel or axle load is stated alongside the letter on this schedule. (6.1.2)

6.2 The load class for each drain area shall be selected.

Grate / drain load classselect

Class A — pedestrian only (≤ 1.5 tonne test load)

Class B — light vehicular, passenger car (≤ 12.5 tonne)

Class C — light commercial / slow traffic (≤ 25 tonne)

Class D — delivery truck / roadway (≤ 40 tonne)

Class E — heavy industrial / forklift (≤ 60 tonne)

Class F — extreme axle load (≤ 90 tonne)

6.3 Trench drains subject to vehicular traffic shall use frames anchored to the surrounding slab to resist horizontal grate creep and rocking under load.

6.4 Grates in vehicular areas shall be locked or bolted to the frame to prevent dislodging under wheel impact.

NOTE An unlocked grate in a traffic lane becomes a projectile under a tire and a fall hazard once displaced; vehicular grates are mechanically secured, not gravity-set. (6.4.1)

7 Floor Drain Construction

7.1 Body Material

7.1.1 The floor drain body material shall be selected to match the load environment, corrosion exposure, and any food-code requirement.

NOTE Cast iron is the default body for general-purpose interior floor drains in mechanical rooms, toilet rooms, and similar areas where neither food service nor aggressive chemistry applies. (7.1.2)

NOTE Stainless steel (Type 304, or Type 316 in chloride or aggressive-chemistry environments) is required where an NSF/ANSI 2 listing, frequent washdown, or corrosion resistance governs. (7.1.3)

Floor drain body materialselect

Cast iron, coated

Stainless steel Type 304

Stainless steel Type 316

PVC / ABS (limited, non-traffic service only)

7.2 Strainer / Grate

7.2.1 Each floor drain shall be furnished with a removable strainer or grate sized for the drain throat.

7.2.2 The strainer or grate material shall match the body material in food-service and corrosive environments to avoid galvanic incompatibility and to maintain the NSF listing.

Floor drain top / strainer materialselect

Nickel-bronze

Cast iron

Stainless steel Type 304

Stainless steel Type 316

Ductile iron

7.2.3 Floor drains within an accessible route shall be furnished with a grate whose openings are no wider than 13 mm (1/2 in) in the predominant direction of travel, per ADA Section 302.3.

7.2.4 Floor drains at exterior building entrances shall be furnished with a heel-proof grate whose openings are no wider than 6 mm (1/4 in).

NOTE Heel-proof grates (≤ 6 mm slot) always satisfy ADA, but not every ADA-compliant grate is heel-proof; where heels, canes, or small wheels are present, specify heel-proof explicitly rather than relying on the ADA dimension alone. (7.2.5)

7.3 Adjustable Top

7.3.1 Floor drains set in cast-in-place slabs shall be furnished with an adjustable top to accommodate construction tolerance and allow the grate to be set flush with the finished floor.

NOTE An adjustable (screw or telescoping) top lets the grate be brought to the finished-floor elevation after the slab is poured, absorbing the inevitable difference between the rough-in elevation and the final finish; a fixed top set proud or low is a trip hazard and a ponding point. (7.3.2)

Top adjustabilityselect

Adjustable (screw / telescoping)

Fixed height

7.4 Sediment Bucket

7.4.1 Floor drains in commercial kitchens, wash bays, and process areas shall be furnished with a removable sediment bucket to intercept solids before the sanitary system.

NOTE Sediment buckets are frequently dropped by value engineering because the plumbing code does not always mandate them; without a bucket, solids accumulate at the outlet and cause recurring blockages downstream. Specify the bucket explicitly where solids are expected. (7.4.2)

Sediment bucket requiredselect

Yes — removable sediment bucket

No

8 Trench Drain Construction

8.1 Channel Body Material

8.1.1 The trench drain channel body material shall be selected for the load class, fluid chemistry, and temperature of the area it serves.

NOTE Polymer concrete is the general-purpose channel for light-to-medium-duty interior and exterior runs with neutral-pH discharge; it offers a smooth bore and good abrasion resistance but degrades under sustained high pH or solvent exposure. (8.1.2)

NOTE Fiber-reinforced and heavy-duty polymer concrete channels carry Class D and Class E loads at loading docks and vehicle wash bays. (8.1.3)

NOTE HDPE channels resist a broad range of chemicals and are favored in corrosive environments and parking structures; they are typically supplied as pre-sloped modular sections. (8.1.4)

NOTE Stainless steel channels (Type 304, or Type 316 for chloride exposure) are required for commercial kitchen, food-processing, and process floors where an NSF/ANSI 2 listing and full washdown cleanability govern. (8.1.5)

NOTE Cast iron channels with integral traps suit mechanical and boiler rooms where high temperature and point-source discharge are present. (8.1.6)

Trench channel body materialselect

Polymer concrete

Fiber-reinforced / heavy-duty polymer concrete

HDPE

Stainless steel Type 304

Stainless steel Type 316

Cast iron

8.2 Channel Width and Depth

8.2.1 The channel width shall be sized from the peak flow rate the run must convey, not chosen by default.

NOTE The peak flow a trench run must carry is a function of the catchment area it drains, the surface slope feeding it, and the discharge source (washdown hoses, process equipment, vehicle drip, or rainfall on an adjacent exterior apron). Width is selected so the channel conveys that peak flow at the design slope without surcharging over the grate; an undersized channel overtops and floods the floor regardless of how many outlets it has. (8.2.2)

NOTE Channel width and grate width are not the same selection — a wide architectural grate can sit over a narrower hydraulic channel. Size the channel bore to the flow and select the grate width for the load class and the opening the floor finish requires. (8.2.3)

8.2.4 The clear channel width shall be specified for each run.

Trench channel clear widthselect

100 mm (4 in)

150 mm (6 in)

200 mm (8 in)

300 mm (12 in)

8.2.5 The channel depth and any required slab depression shall be coordinated with the structural slab; the slab blockout or depression dimension shall appear on the structural drawings. The depression extent and depth are shown at channel slab depression.

NOTE The slab depression depth needed to receive a trench drain is frequently absent from the structural documents and surfaces as an RFI during formwork; carry the channel depth and required depression onto the structural drawings before the slab is formed. (8.2.6)

8.3 Slope Method

8.3.1 The channel slope method (factory pre-sloped modular or field-sloped continuous) shall be specified.

NOTE Pre-sloped modular channels arrive with the invert slope built in, which improves accuracy and reduces field labor, but they come in fixed length increments; a run that does not fit standard module lengths needs a custom end piece or a site-sloped continuous channel. Confirm the run length against the module catalog before specifying pre-sloped. (8.3.2)

Channel slope methodselect

Factory pre-sloped (modular)

Field-sloped (continuous, neutral channel)

8.3.3 A minimum built-in or field-set slope shall be maintained toward the outlet so the channel self-drains.

Minimum channel slope to outletrange

%

0.51.5

Default: 0.6 %

8.4 Trench Grate

8.4.1 Each trench drain shall be furnished with a removable grate rated for the specified load class and secured to the frame as required for the traffic category.

8.4.2 The grate material shall be selected for the load class, corrosion environment, and any NSF requirement.

NOTE Ductile iron grates carry the highest vehicular loads and are the default for Class D and above. Stainless steel grates are required in food-service and corrosive areas. Galvanized steel and polymer grates suit lighter-duty and non-traffic runs. (8.4.3)

Trench grate materialselect

Ductile iron

Cast iron

Galvanized steel

Stainless steel Type 304

Stainless steel Type 316

Polymer / composite

8.4.4 Trench grates within an accessible route shall present openings no wider than 13 mm (1/2 in) measured perpendicular to the dominant direction of travel, per ADA Section 302.3.

NOTE A parallel-bar grate satisfies ADA only when the bars run perpendicular to travel; installed with the slots running along the path of travel, the same grate fails ADA. Specify the bearing-bar orientation relative to travel, not just the slot width. (8.4.5)

Trench grate pattern / ADA complianceselect

Heel-proof slot (≤ 6 mm, ADA-compliant)

ADA-compliant slot (≤ 13 mm perpendicular to travel)

Slotted (non-accessible area)

Open bar / mesh (non-accessible area)

8.5 Trench Sediment Bucket

8.5.1 Trench drains serving wash bays, commercial kitchens, and process floors shall be furnished with a sediment bucket or sump at the outlet to intercept solids.

Trench sediment bucket / sump requiredselect

Yes — sediment bucket at outlet

No

9 Outlets

9.1 The outlet size, orientation, and invert elevation of each drain shall be coordinated with the sanitary piping system and shown on the plumbing drawings.

NOTE A mismatch between the factory-set outlet elevation and the field-installed sanitary invert is a leading RFI source; confirm the outlet invert on the plumbing plan against the structural slab depression before the drain is set. (9.1.1)

9.2 The outlet orientation shall be selected for each drain.

Outlet orientationselect

Bottom outlet

End outlet

Side outlet

9.3 The outlet diameter shall be selected to match the connecting sanitary branch.

Outlet nominal diameterselect

75 mm (3 in)

100 mm (4 in)

150 mm (6 in)

9.4 Long trench runs with high peak flow shall be provided with multiple outlets where a single outlet cannot convey the design flow; the number and location of outlets are shown at trench outlet locations.

10 Traps and Trap Primers

10.1 Every floor drain and trench drain connected to the sanitary system shall be trap-protected, either by an integral trap or by a remote trap in the branch.

10.2 The trap type for each drain shall be selected.

Trap configurationselect

Integral P-trap (cast into drain body)

Remote P-trap in branch

10.3 Floor drains and trench drains that are used infrequently shall be furnished with a trap primer to maintain the trap seal, per IPC Section 1002.

NOTE An infrequently used drain loses its trap seal to evaporation, opening a path for sewer gas into the occupied space; the trap primer replenishes the seal automatically. This requirement is commonly omitted where the plumbing and mechanical drawings are not cross-coordinated. (10.3.1)

10.4 The trap primer type shall be selected.

Trap primer typeselect

Automatic pressure-differential (plumbing-fed)

Electronic / timed (requires 120 V circuit)

Manual

10.4.1 Where an electronic trap primer is specified, the required 120 V circuit shall be coordinated with the electrical drawings.

NOTE Electronic primers need a dedicated circuit that is routinely forgotten on the electrical documents; coordinate the primer power with the plumbing engineer and confirm it appears on the electrical drawings before rough-in. (10.4.2)

11 Waterproofing Integration

11.1 Floor drains and trench drains that penetrate a waterproofed slab shall be furnished with a clamping-ring (membrane-clamp) assembly that seals the waterproofing membrane to the drain body.

NOTE A drain through a waterproofed parking deck, plaza, or kitchen slab over occupied space is a deliberate hole in the waterproofing; the clamping ring captures and seals the membrane to the drain so water cannot bypass the drain at the penetration. Omitting it creates a major leak path discovered only after the floor finish is in place. (11.1.1)

11.2 The clamping-ring assembly shall be compatible with the specified waterproofing membrane type; coordinate with Fluid Applied WaterproofingFluid-Applied WaterproofingResolves to the current edition.sync/fluid-applied-waterproofing and Below Grade WaterproofingBelow-Grade WaterproofingResolves to the current edition.sync/below-grade-waterproofing for membrane termination at the drain.

11.3 A clamping-ring (membrane-clamp) drain shall be specified for each drain that penetrates a waterproofed slab.

Waterproofing clamping ring requiredselect

Yes — membrane clamp / flashing flange

No — non-waterproofed slab

11.4 Drains set in resinous or seamless floors shall be detailed so the floor finish terminates into the drain flange; coordinate the drain top and flange with Resinous FlooringResinous FlooringResolves to the current edition.sync/resinous-flooring.

NOTE A resinous floor needs a positive edge to key into at the drain — typically a recessed flange or a flashing clamp that the coating wraps into and that is then keyed back. Without that detail the coating feathers to a thin, unsupported edge at the grate and chips away, opening a path for water under the floor. (11.4.1)

11.4.2 Food-service drains in splash and food-contact zones shall present radius-coved interior corners and no exposed threads in the food zone, consistent with the NSF/ANSI 2 listing.

NOTE Square interior corners and exposed threads trap food soil and resist cleaning, which is why the NSF listing calls for coved radii and concealed fasteners in the food zone; verify the listed assembly provides them rather than assuming a stainless body alone qualifies. (11.4.3)

12 Testing

12.1 Each drain assembly and its branch shall be tested for leaks as part of the sanitary system test before the floor finish is placed.

12.2 Each trench run shall be water-tested for slope by flooding the channel and confirming it self-drains to the outlet with no standing water.

NOTE A flood test on the bare channel before the finished floor goes down catches a flat or reverse-sloped section while it can still be corrected; once the surrounding floor is poured, a low spot is permanent. (12.2.1)

12.3 Grate fit shall be verified so each grate seats flush with the finished floor and does not rock under load.

Field tests performedcheckbox

☐ Drain and branch leak test

☐ Trench slope flood test (self-drains, no ponding)

☐ Grate flush-seat and rock check

13 Installation

13.1 Drains and channels shall be installed per the manufacturer's instructions and at the inverts shown on the coordinated plumbing and structural drawings.

13.2 Trench channels shall be fully encased and supported per the manufacturer's instructions during the concrete pour so the channel does not float, deflect, or shift out of line.

NOTE A trench channel that floats or twists during the pour locks in a misaligned grate line and a compromised slope; channels are staked, braced, and often filled or strapped before concrete placement. (13.2.1)

13.3 Grates shall be installed or covered to protect them from the concrete pour and subsequent trade damage, and the channel bore shall be kept clear of concrete and debris.

13.4 Floor drain bodies shall be set so the adjustable top can bring the grate flush to the finished-floor elevation after the slab is poured.

13.5 Drains shall be set at the low point of the floor's drainage slope so the surrounding floor pitches toward the drain.

NOTE A drain set above the local low point leaves a ring of standing water around it; the floor finish must pitch to the drain, and the drain must sit at the true low point of that pitch. (13.5.1)

14 Delivery, Storage, and Handling

14.1 Drains, channels, and grates shall be delivered in the manufacturer's packaging and stored off the ground and protected from damage until installation.

14.2 Grates and strainers shall be kept with their matching bodies and channels so load-rated and NSF-listed assemblies are not mixed during installation.

14.3 Stainless steel components shall be protected from contact with carbon steel and from chloride-bearing dust to prevent surface rusting and pitting before the floor is closed in.

15 Warranty

15.1 The manufacturer shall warrant the drain and channel assemblies against defects in materials and workmanship for the period specified below.

Manufacturer warranty periodrange

years

15

Default: 1 years

16 Spare Parts

16.1 The Contractor shall furnish spare grates, strainers, and sediment buckets as specified below for maintenance replacement.

NOTE Spare grates matter most where the installed grate is a long-lead or custom item (heavy load class, stainless food-service, or a non-standard width); a damaged grate in a traffic lane is a hazard that should be replaceable from stock rather than re-ordered. (16.1.1)

Spare grates / strainers furnished (% of installed quantity)range

%

010

Default: 2 %

Spare sediment buckets furnishedcheckbox

☐ One spare sediment bucket per drain type with a bucket

NOTE --- (16.1.2)

NOTE Copyright SynC. Licensed CC BY-SA 4.0. Independently authored from public consensus standards, model plumbing codes, and manufacturers' published technical data; contains no proprietary guide-specification text. (16.1.3)