Fixtures, Fixture Fittings, and Appliances
What the exam tests
This domain covers fixture selection, clearances, supports, traps, water efficiency, and appliance connections. The exam tests whether a fixture can be used, cleaned, and connected without cross-connection or structural problems.
Core rules
- Fixtures must be approved, installed per the manufacturer, and accessible for cleaning and repair.
- Water closets need at least 15 in from centerline to a side wall and adequate compartment depth; lavatories need usable clearance.
- Floor drains, shower drains, and appliances need traps and venting; appliance connectors must be listed and accessible.
- Provide backflow protection for hose bibbs, dishwashers, beverage equipment, and other connections.
- Support fixtures securely; do not rely on piping for support.
Worked example
A bathroom is 60 in wide and the water closet is centered on the end wall. Centerline to each side wall = 30 in. The 15-in side-clearance rule is met with room to spare. If the room were 28 in wide and the closet centered, centerline to side wall would be 14 in, which fails; widen the space or shift the fixture so one side meets 15 in.
Traps that cost marks
Ignoring side clearance; installing a fixture trap above the fixture outlet; connecting a dishwasher without an air gap or approved backflow device; blocking access to a cleanout; using an unlisted appliance connector.