Red Seal Plumbing Practice Exam

Trap arms and fixture drains should have a downward slope of how much per foot for trap arm lengths less than 3 inches?

1. 1/2 inch

2. 1/4 inch

3. 1 inch

4. 3/4 inch

The correct answer is: 1/4 inch

The downward slope of a trap arms and fixture drains is crucial for proper drainage and preventing water backup. A slope that is too steep may cause water to drain too quickly and not effectively eliminate waste, while a slope that is too gradual may cause water to pool and create blockages. Option A, 1/2 inch per foot, is too steep and would result in inadequate waste removal. Option C, 1 inch per foot, is too gradual and could lead to blockages. Option D, 3/4 inch per foot, is also too gradual and could cause water to pool in the pipes. Therefore, option B, 1/4 inch per foot, is the correct answer for trap arm lengths less than 3 inches.