WorksheetsChapter 11: Storm Drainage
Total questions: 15
Worksheet time: 8mins
Where should stormwater be discharged according to regulations?
a) Into a sanitary sewer
b) Into an approved disposal point
c) Into any open land area
d) Into a septic tank
Which material is NOT approved for rainwater downspouts inside a vertical pipe chase?
a) Cast iron
b) Galvanized steel
c) Polyvinyl chloride (PVC)
d) Clay pipes
Downspouts for high-rise buildings must be made of stronger materials to resist:
a) Earthquake shocks
b) High hydrostatic pressure
c) Wind loads
d) Snow accumulation
Which of the following statements about rainwater piping is TRUE?
a) Rainwater piping can be used as a vent pipe
b) Rainwater piping must be tested and accepted before use
c) Rainwater piping should be connected to wastewater pipes
d) Rainwater piping should always be made of copper
How high should dome-type strainers extend above the roof surface?
a) At least 25 mm
b) At least 50 mm
c) At least 100 mm
d) Flush with the roof surface
What type of roof drain strainer is required for sun decks and parking decks?
a) Dome-type
b) Flat-surface type
c) Funnel-type
d) Mesh-type
What is the standard rainfall intensity used for pipe sizing in Metro Manila?
a) 50 mm/hour
b) 76 mm/hour
c) 102 mm/hour
d) 127 mm/hour
If a vertical wall projects above a roof and drains onto it, what percentage of the wall area should be added to the roof area?
a) 25%
b) 50%
c) 75%
d) 100%
If two adjacent walls drain onto a lower roof, how much of the total wall area is added to the roof area?
a) 25%
b) 35%
c) 50%
d) 75%
When two opposite walls of equal height drain onto a roof, how much wall area is added?
a) 0%
b) 25%
c) 50%
d) 75%
Roof gutters should be sized based on:
a) Maximum wind speed in the area
b) The size of the building’s windows
c) Maximum roof area and rainfall intensity
d) The length of the downspouts
If a semi-circular roof gutter is too small for the expected stormwater load, what is the best solution?
a) Increase the gutter depth
b) Increase the gutter width
c) Add more downspouts
d) Use a steeper roof pitch
If the actual rainfall rate is higher than that listed in Table 11-2, how is the capacity of a pipe adjusted?
a) Multiply by 0.5 and divide by the rainfall rate
b) Multiply by 2 and divide by the rainfall rate
c) Multiply by the roof area and divide by the pipe slope
d) Keep the values the same regardless of rainfall intensity
What should be considered when designing a storm drainage system?
a) Building height and window placement
b) Rainfall intensity and roof area
c) Color and style of the roof
d) The number of building occupants
What is the main function of a roof drain?
a) To prevent debris from entering the downspout
b) To store rainwater temporarily
c) To increase the water pressure in the drainage system
d) To direct stormwater into the sewage system
