10.2 DWV Piping Materials

10.2 DWV Piping Materials

Quick Answer: Install only 248 CMR 10.06 Table 1 storm, sanitary, and vent materials that are also Board Product-accepted under 248 CMR 3.04. Cast iron (extra-heavy, service weight, no-hub) is allowed above and below ground. PVC/ABS Schedule 40 is Table 1–listed, but 10.06(2)(g) limits it to residential-type occupancies not exceeding ten stories on the building permit, plus a narrow mixed-use employee-floor exception. Do not put commercial kitchen, laundry, or public-toilet waste on PVC in a hotel or assisted-living commercial area, and do not dump commercial waste into a PVC residential stack. Copper DWV (yellow) and Type M (red) are not underground DWV on Table 1; Type K and Type L are. Urinal branches outside residential-type buildings stay cast iron or iron-size copper/brass.

PSI groups DWV: Materials inside the larger drain-waste-vent written domain. Massachusetts is a UPC-derived state code, not IPC. Independent OpenExamPrep teaching uses the 12/8/2023 text of 248 CMR 10.06. It is not a Board publication and it does not claim official approval.

Product-acceptance is the gate; Table 1 is the map

248 CMR 10.06(1)(a) requires every product, system, and equipment used in plumbing or drainage to meet 10.06 and 248 CMR 3.04 Product, Design, and Testing Standards. A pipe that “is ASTM” on a truck sticker is still illegal if the Board has not Product-accepted that product for that use. 10.06(1)(c)–(d) let the Board accept a substantial equivalent, a Variance, or Test-site status — those are Board actions, not a journeyman field call.

248 CMR 10.06(1)(b) is the renovation relief: the Inspector may allow extension, addition, or relocation of existing water, soil, waste, and/or vent pipes with materials of like grade or quality where the original installation met the code then in effect. That is matching what is already in the wall. It is not a license to rough a new commercial kitchen in leftover residential PVC.

248 CMR 10.06(2)(c) and (d) send storm and sanitary above and below ground, and vent pipe and fittings above and below ground, to Table 1. The table’s legend is A = Allowed, X = Not Allowed. Follow manufacturer instructions wherever they are more stringent. Special waste materials live in 248 CMR 10.13(2), not on a guess from Table 1.

Verified Table 1 pattern from the 12/8/2023 listing:

Polypropylene and polyethylene drainage-pattern rows are marked allowed on Table 1, but 10.06(2)(h) and 3.04 still control other plastics. Do not treat those rows as a free substitute for commercial cast iron.

Floor flanges for toilets and similar fixtures shall be Product-accepted and made of copper, brass, cast iron, hubless cast iron, or plastic (10.06(2)(b)). Sheet copper for safe pans, shower pans, flush-tank linings, and vent-terminal flashing shall be not less than 12 ounces per square foot (10.06(2)(a)).

PVC and ABS: ten stories, the permit card, and mixed use

248 CMR 10.06(2)(g) is the overlay every Table 1 PVC/ABS “A” still has to survive.

Where Schedule 40 PVC/ABS DWV may be used

1. Drains, waste, or vents in residential dwellings, hotels, motels, inns, condominiums, and residential areas of assisted living facilities not exceeding ten stories; or
2. A predominantly residential building with a single non-residential use on a single floor that is categorized exclusively as employee (non-residential) under 248 CMR 10.10(15) Table 1, limited to a maximum of four plumbing fixtures, and limited to toilets, lavatory / residential / service sinks, and drinking water stations.

Ten stories are determined by the building permit. If no building permit is required, the authority having jurisdiction decides. The Mass.gov PVC for Mixed Use Installation Scenarios interpretation (enacted 05-29-2013) makes that permit-card rule concrete:

• Example 1. Nine levels above grade plus two parking levels below grade, and the building permit lists 11 stories → no PVC.
• Example 2. The same physical building, but the permit lists 9 stories → PVC is allowed (still subject to the commercial-waste isolation below).

Do not count stories with a tape and a parking-garage argument if the card already numbered the building.

Where PVC/ABS Schedule 40 shall not be used (10.06(2)(g)3.)

Not for drains, waste, or vents in commercial kitchens, laundry rooms, public toilet facilities, or other commercial areas located in assisted living facilities, hotels, motels, inns, or similar establishments. See 10.06 Example 1 (PVC limited allowances in mixed-use buildings ten stories and under).

The mixed-use Board interpretation adds the stack rule examiners love: no commercial waste shall enter into PVC. A second-floor office branch is cast iron (or other commercially accepted Table 1 metal). Residential bathroom groups may stay on PVC. You may transition at the point the diagram allows — you may not comb a coffee-shop grease line into the residential PVC stack. 780 CMR firestopping of those plastic penetrations is a building official enforcement item; it does not convert a commercial waste into a PVC permission.

Limited commercial exceptions (10.06(2)(g) Exception). Schedule 40 PVC/ABS may serve fixtures used only for that business in:

• hair-wash / color sinks in barber shops and beauty salons;
• manicure and pedicure fixtures;
• photo-lab processing equipment; or
• alcohol, soda, or similar carbonated-beverage fixtures in commercial buildings (those fixtures may discharge indirectly; transition to commercially accepted materials immediately after the point of dilution; 248 CMR 10.12(1)(a)2.).

Those limited wastes must connect to a main or branch drain serving other fixtures so there is a dilution point. The vent from the discharging fixture extends to 6 inches above the flood rim, then re-transitions to cast iron or copper as used in the rest of the commercial building.

Further narrow permissions: Type 1 PVC as indirect waste for dialysis equipment in medical buildings; PVC Schedule 40 perforated pipe for sub-soil drainage in commercial buildings (storm/sub-soil, not a sanitary stack). Thermal expansion of PVC DWV still goes to 10.05(7)(e).

Urinal wastes, no-hub, and engineered systems

248 CMR 10.06(2)(i) is stricter than Table 1’s general PVC row. Urinal waste branches and urinal fixture wastes shall be:

1. Extra-heavy or service-weight cast iron with caulked joints; or
2. Extra-heavy, service-weight, or no-hub cast iron with resilient gaskets or no-hub clamps with elastomeric sleeves; or
3. Threaded cast iron with cast-iron drainage fittings; or
4. Iron-size copper or brass with cast-brass drainage fittings; or
5. PVC/ABS Schedule 40 only in residential-type buildings.

Schedule 80 PVC or CPVC threaded nipples may be the final connection of toilets and urinals to carriers and fittings. That nipple is not permission to run the urinal branch in Schedule 40 through a commercial toilet room.

Scenario. A ten-story Boston hotel on the permit: guest-room PVC is a 10.06(2)(g)1. conversation. The ground-floor public toilet and the commercial kitchen are not PVC. Urinal branches on that public toilet are cast iron or iron-size copper/brass. A nine-story mixed-use building with a 1,800-square-foot second-floor office and residential units above: keep the office on cast iron, keep residential DWV on PVC if the permit story count allows, and do not combine the office waste into the PVC stack.

So-vent (single-stack) and vacuum drainage are engineered systems. A Massachusetts professional engineer designs them; the plumbing Inspector inspects installation against 248 CMR but is not the designer; an affidavit goes to the Inspector before final inspection. Vacuum piping, when used, is Type K, L, M, or DWV hard-drawn copper or cast iron with DWV-pattern fittings (10.06(2)(k)–(l)). Those systems are not a shortcut around Table 1 for an ordinary soil stack.

Do not pick DWV pipe from an IPC materials chapter. Table 1 plus 10.06(2)(g) plus 3.04 is the Massachusetts answer.

Official resources

• 248 CMR 10.06 Materials (Cornell) — Table 1, 10.06(2)(g) PVC/ABS, urinal wastes
• 248 CMR 10.00 (Mass.gov, effective 12/8/2023) — official Table 1 PDF
• PVC for Mixed Use Installation Scenarios (Mass.gov) — permit stories; no commercial waste into PVC
• 248 CMR 10.00 Uniform State Plumbing Code (Mass.gov regulation page) — 12/8/2023 posting