3.2 Fixture Installation: Clearances, Compartments, Connections, Showers & Accessibility

Setting fixtures (IPC 405.1 to 405.3)

• 405.1: supply lines and fittings must prevent backflow.
• 405.2: fixtures must allow easy access for cleaning the fixture and the surrounding area.
• 405.3: fixtures must be set level and in proper alignment with adjacent walls.

Clearances (405.3.1)

The 15-inch side clearance on each side gives the familiar 30-inch minimum compartment width.

Other placement rules

• 405.3.2: in employee and public toilet rooms, the required lavatory must be in the same room as the required water closet. Virginia's exception allows educational occupancies to place it adjacent to the room, with no more than one operational door between the water closet and the lavatory.
• 405.3.3: piping, fixtures and equipment must not interfere with the normal operation of windows, doors or other egress openings.

Compartments and urinal partitions (Virginia 405.3.4 and 405.3.5)

Virginia rewrote both sections:

• Water closet compartments (405.3.4): every water closet used by the public or employees must comply with 405.3.4.1 or 405.3.4.2, and all fully enclosed compartments must have occupancy indicators. In separate facilities, each water closet is in its own compartment with walls or partitions and a door. In multi-user gender-neutral facilities, the partitions and doors run from floor to ceiling, with gaps of no more than 1/2 inch at the floor and ceiling and no more than 1/8 inch between doors and partitions. Exceptions: a single-occupant room with a lockable door; child day care rooms with two or more water closets may leave one without a compartment; and I-3 housing areas.
• Urinal partitions (405.3.5): each urinal used by the public or employees must be in a separate area with walls or partitions. The horizontal distance between walls or partitions at each urinal must be at least 30 inches. The partitions must begin no more than 12 inches above the floor and extend at least 60 inches above the floor. They must project from the wall at least 18 inches, or to at least 6 inches beyond the urinal's outermost front lip, whichever is greater. Exceptions: single-occupant or family/assisted-use rooms with a lockable door, and child day care rooms with two or more urinals, which may leave one without a partition. In multi-user gender-neutral rooms, urinals need floor-to-ceiling compartments or a separate room with a door (405.3.5.2).

Connections (IPC 405.4 to 405.10)

• 405.4: a floor-outlet fixture connects to the drain with a floor flange, or a waste connector and sealing gasket tested to ASME A112.4.3. The flange is attached to the drain and anchored to the structure. Wall-hung water closets connect with an approved extension nipple or horn adapter and are bolted to the hanger with corrosion-resistant bolts.
• 405.4.1 flange thickness: copper alloy at least 0.125 inch; plastic at least 0.25 inch; cast iron or galvanized malleable iron at least 0.25 inch with a 2-inch caulking depth. Hard-lead flanges must weigh at least 1 pound 9 ounces and contain at least 7.75% antimony. Closet screws and bolts must be copper alloy.
• 405.4.2: floor-outlet fixtures are secured with corrosion-resistant screws or bolts.
• 405.4.3: a wall-hung water closet bowl is supported by a concealed metal carrier attached to the structure, so that no strain reaches the fixture connector. The carrier must meet ASME A112.6.1M or A112.6.2.
• 425.4: a 4-by-3-inch closet bend is acceptable. Where a 3-inch bend is used, a 4-by-3-inch flange receives the fixture horn.
• 405.5: fixtures with pumped waste meet ASME A112.3.4/CSA B45.9.
• 405.6: joints where fixtures meet walls or floors must be sealed.
• 405.7: in mental health centers, pipes and traps must not be exposed and fixtures are bolted through walls.
• 405.8 and 405.8.1: standing water must not rise in an overflow when the stopper is closed. Overflows discharge on the inlet side of the trap. Exception: a flush tank overflow discharges into the fixture it serves.
• 405.9: slip joints need approved elastomeric gaskets and are allowed only on the trap inlet, the trap outlet and within the trap seal. A fixture with concealed slip joints needs an access panel or utility space at least 12 inches in its smallest dimension.
• 425.2 and 425.3: public and employee water closets need elongated bowls and hinged open-front seats.

Fixture outlet sizes

Showers (IPC 421)

• 421.2: the riser from the shower valve to the showerhead outlet must be attached to the structure.
• 421.4 compartment size: at least 900 square inches of interior cross-sectional area and at least 30 inches in least dimension, measured from the finished interior surfaces at the top of the threshold, and continued up to 70 inches above the drain. Exception: 25 inches in least dimension is allowed where the area is at least 1,300 square inches.
• 421.4.1: walls must be smooth, corrosion-resistant, nonabsorbent and waterproof to at least 6 feet above the floor and at least 70 inches above the drain.
• 421.4.2: the access opening must be at least 22 inches clear.
• 421.5.2 liners: turn up at least 2 inches above the finished threshold; no nails or holes less than 1 inch above the threshold; slope 1/4 inch per foot toward the drain. Liners are tested with water at least 2 inches deep at the threshold for 15 minutes (312.9).
• 421.6 and 407.3: glazing in shower and bathtub enclosures follows the IBC safety glazing rules.

Accessibility (IPC 404 and ICC A117.1)

Accessible fixtures are required by IBC Chapter 11 and installed to ICC A117.1 (404.1 and 404.2). The 2021 IBC references the 2017 edition of A117.1. IPC 404.3 requires water supply and drain pipes under accessible lavatories and sinks to be covered or otherwise configured to protect against contact, using covers that meet ASME A112.18.9 or ASTM C1822.

Common A117.1 dimensions for adult fixtures:

Note the difference: the IPC's general rule is a minimum 15-inch centerline clearance, while the accessible water closet uses a 16-to-18-inch range from the side wall.

Other fixture connections

• 406.1 and 406.2: an automatic clothes washer's water supply is protected by an integral air gap or a backflow preventer. It drains through an air break into a standpipe (802.4.3) or into a laundry sink. The standpipe trap and fixture drain must be at least 2 inches and connect to a 3-inch or larger branch or stack.
• 409.4: a residential dishwasher drains to a wye on the sink tailpiece, to the disposer's dishwasher inlet, or through an air break to a standpipe. Its waste line must rise and be fastened to the underside of the sink rim or countertop.
• 426.5: a whirlpool tub pump needs access. Without manufacturer guidance, provide an opening of at least 12 by 12 inches, or 18 by 18 inches where the pump is more than 2 feet from the opening.