Fixtures and Fixture Fittings Both Codes Agree On — Setting, Flanges, Overflows, Flow Rates, Temperature Limits, Showers, Flushing Devices, Minimum Facilities (UPC ch. 4 / IPC ch. 4)
Fixture questions are the bread and butter of the tradesman and journeyman exams: how far a water closet sits from the wall, how big a lavatory outlet is, how hot a tub filler may run, what a shower pan is made of, how many toilets a building needs. The 2018 UPC (ch. 4) and 2018 IPC (ch. 4, with the flow-rate table in 604.4) agree on the rules below. Where they disagree (front clearance, urinal spacing, shower outlet size, shower area, drinking-fountain thresholds, fixture-count tables) the difference is listed in §10 and no question is written on it.
2018 UPC and 2018 IPC · Reviewed 2026-09-20
1. Materials and quality
- Fixtures are made of dense, durable, non-absorbent material with smooth, impervious surfaces free of (unnecessary) concealed fouling surfaces (UPC 401.2; IPC 402.1). The IPC adds that porcelain enamel must be acid-resistant.
- Special-use fixtures: soapstone, chemical stoneware, copper-based alloy, nickel-based alloy, corrosion-resistant (stainless) steel or other suitable material (UPC 406.3; IPC 402.2).
- Sheet lead for pans: not less than 4 lb/ft², asphalt-coated. Sheet copper: ASTM B152, not less than 12 oz/ft² (UPC 408.7.3–.4; IPC 402.3–402.4, 421.5.2.3–.4).
- Prohibited: water closets with an invisible (concealed) trap seal, an unventilated space, or walls not thoroughly washed at each flush; any water closet that could siphon bowl contents back into the tank; trough urinals (UPC 405.1–405.2; IPC 401.2).
- Baptisteries, ornamental and lily pools, aquaria and ornamental fountains: water and waste connections submitted for approval and the supply protected against backflow (UPC 406.1; IPC 423.1–423.2).
This is where the public part ends.
The rest of this lesson, its quiz, all 1 lessons in the module and every mock exam open with the 7-day pass for $9. If you stay, it comes off lifetime.