QUESTION 10
Using your knowledge of the NZ Building Code complete the following multi choice questions.

1 A ventilating pipe may be omitted if the length of a single waste pipe to a gully trap is less than:
 a) 4.8 m 
 b) 4. m 
 c) 4.2 m 
 d) 3.9 m 
 e) 3. m 

2  The recognised term for the system where unventilated fixtures discharge foul water or waste
water into a common discharge pipe is:
 a) the combined waste system.
 b) the one-pipe system. 
 c) the two-pipe system.   
 d) the single-stack system.   
 e) the soil-waste system. 

3 Traps are fitted to waste pipes:
 a) to prevent vermin entering a building.   
 b) to reduce the velocity of discharge.   
 c) to prevent foul gases entering a building.   
 d) to exclude sewer gases from a waste pipe. 
 e) to provide aerial disconnection of a waste pipe. 

4 A drinking fountain is classed as:
 a) a sanitary fixture. 
 b) a sanitary appliance.
 c) a public facility. 
 d) a soil fixture. 
 e) trade waste. 

 When a vent pipe connects to a 0 mm urinal waste it must have a minimum diameter of:
 a) 20 mm 
 b) 2 mm 
 c) 32 mm 
 d) 40 mm 
 e) 0 mm 

6 The minimum permissible gradient of a 0 mm diameter waste pipe is:
 a) 1 in 40 
 b) 1 in 30 
 c) 1 in 2 
 d) 1 in 20 
 e) 1 in 1 

7 The minimum diameter of the outlet of a water closet pan is:
 a) 6 mm 
 b) 7 mm 
 c) 80 mm 
 d) 8 mm 
 e) 100 mm 

8 The function of a ventilating pipe is:
 a) to allow organic matter to dry out. 
 b) to allow foul air to escape.   
 c) to prevent foul air entering a building. 
 d) to prevent siphonage.   
 e) all of the above.     

9 The main purpose of a trap vent is:
 a) to allow foul smells to escape.   
 b) to prevent foul odours entering a building.
 c) to prevent the loss of water seals. 
 d) to allow cleaning access.   
 e) to provide a quicker discharge rate. 

10 For five floor waste outlets connected to a common stack, the stack diameter is:
 a) 32 mm
 b) 40 mm
 c) 0 mm
 d) 6 mm
 e) 80 mm

(1 mark each)

Total 10 marks

Linkback: https://www.plumbers.nz/plumbing-exam-2006/19/question-10/134/