Home Inspector Plumbing DWV Systems Flashcards
7 cards from real Home Inspector Test practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Home Inspector Plumbing DWV Systems flashcards as text
When inspecting a two-story home, the inspector finds that a second-floor bath drain connects directly to the vent stack above the first-floor drain connection. What is this arrangement called?
Answer: Wet venting
Wet venting is when a single pipe serves as both a drain and a vent, which is permitted under specific code conditions for certain fixture combinations.
A home inspector notices that a vent pipe terminates in an attic rather than penetrating through the roof. What is the deficiency?
Answer: Sewer gases will accumulate in the attic, creating a health hazard
Vent pipes must terminate outdoors above the roofline; terminating in an attic allows toxic sewer gases to accumulate in the structure.
What is the purpose of a 'relief vent' in a drainage system?
Answer: To provide additional air circulation to prevent pressure buildup in long horizontal runs
A relief vent connects a drain stack to a vent stack partway up to relieve air pressure differentials in tall or complex drainage systems.
During a home inspection, the inspector tests all drains and finds that the kitchen sink drains slowly while all other fixtures drain normally. What is the most likely cause?
Answer: There is a localized blockage in the kitchen sink drain or trap
A slow drain isolated to one fixture points to a local clog in that fixture's trap or branch drain rather than a main line or vent issue.
Which of the following pipe materials is most resistant to chemical drain cleaners and is commonly used for residential DWV systems in modern construction?
Answer: PVC Schedule 40
PVC Schedule 40 is the standard material for residential DWV systems; it is chemically resistant, lightweight, affordable, and code-approved.
An inspector observes that a 3-inch horizontal drain pipe has a slope of 1/2 inch per foot. What concern should the inspector note?
Answer: The slope is too steep and solids may separate from liquid, causing clogs
Excessive slope causes water to run ahead of solids, leaving waste behind to accumulate and eventually clog the pipe.
A home inspector finds black staining and soft drywall around the base of a soil stack in the basement. Which deficiency does this most likely indicate?
Answer: A leak at a pipe joint allowing sewage to contact the structure
Black staining and soft drywall near drain piping strongly suggest an active or past sewage leak at a joint, requiring immediate professional repair.