topic 10: storm drainage system

Question 1

What are the 6 roofing elements to collect rainwater?

Answer 1

1. gutter
2. downspout
3. strainer or roof drain
4. shoe
5. storm line
6. catch basin

Question 2

____ is usually located along the entire perimeter of the roof.

Answer 2

gutter

Question 3

___ is located every 8 to 10 meters and at every corner of the roof (but to avoid clogging of pipes, it is best to locate them every 4 to 6 meters.

Answer 3

downspout

Question 4

Downspout is located every 8 to 10 meters and at every corner of the roof (but to avoid clogging of pipes, it is best to locate them every _____.

Answer 4

4 to 6 meters

Question 5

____ is designed to receive water collecting on the surface of a roof and to discharge it into a downspout.

Answer 5

strainer or roof drain

Question 6

___ is designed to prevent clogging.

Answer 6

strainer or roof drain

Question 7

____ is at the bottom of the roof leader to direct rainwater towards the nearest catch basin.

Answer 7

shoe

Question 8

____ connects to each catch basin.

Answer 8

storm line

Question 9

____ downspouts should terminate in a catch basin (can serve more than one downspout).

Answer 9

catch basin

Question 10

____ delivers water to the sewers in the street via gravity.

Answer 10

catch basin

Question 11

_____ also collects surface water.

Answer 11

area-drain catch basin

Question 12

_____ carries only rainwater collected from the storm drain or from the streets.

Answer 12

storm sewers

Question 13

_____ terminates at natural drainage areas (i.e. lakes, rivers, and water reservoirs).

Answer 13

storm sewers

Question 14

Storm sewers require manholes to serve as cleanouts and to make sewers accessible for inspection and repair built at depths of about ______; diameter ranging from _____.

Answer 14

2 to 3 meters, 0.6 to 1.2 meters

Question 15

What are 2 rainwater pipes?

Answer 15

1. downspouts or conductor pipes, gutters
2. roof drains

Question 16

_____ shall not be used as soil, waste and vent pipes.

Answer 16

rainwater piping

Question 17

_____ sizes are based upon the maximum depth of rainfall per hour falling upon a given roof area in square meters.

Answer 17

downspout and gutter

Question 18

An ave. ___ rainfall intensity for downspouts and gutter sizes is used around Metro Manila.

Answer 18

102 mm/hr

Question 19

Round, square (sized to enclose its equivalent round pipe) or rectangular (shall have at least the same cross-sectional area as its equivalent round pipe, except that the ratio of its side dimensions shall not exceed ____) rainwater pipes may be used for downspouts.

Answer 19

3 to 1

Question 20

____ for high-rise buildings shall be of stronger pipe materials to resist the high hydrostatic pressure, they shall be installed within a pipe chase, and have no intermediate branch from the roof to the ground level.

Answer 20

downspouts

Question 21

_____ shall be equipped with dome type strainers extending 102 mm above the surface of the roof surface.

Answer 21

roof drains

Question 22

Roof drains with a minimum total net inlet area of ____ times the area of the outlet pipe to which it is connected.

Answer 22

1 – ½

Question 23

_____ shall be approved flat surface type, with a total net inlet area not less than 2 times the area of the outlet pipe to which the drain is connected.

Answer 23

roof deck strainers

Question 24

_____ passing through building interiors shall be made watertight by the use of C.I. drain with integrally-cast waterstop ring around the outside of the body and placed at mid-depth of the concrete roof slab and the installation of a clamped suitable flashing material around the drain.

Answer 24

roof drains

Question 25

What are the 3 major systems of collecting storm water?

Answer 25

1. the independent system
2. the combined system
3. the natural system

Question 26

____ a.k.a. “The Separate System”.

Answer 26

the independent system

Question 27

_____ brings the collected water directly to the water reservoirs.

Answer 27

independent system

Question 28

____ combines storm water with sanitary wastes.

Answer 28

combines system

Question 29

____ is without using any roof gutters or downspouts.

Answer 29

natural system

Question 30

In ____, rainwater is collected in cisterns.

Answer 30

natural system