Storm Drainage System - PLUMBING AND SANITARY SYSTEMS

Storm Drainage Systems - ARBU 121

1. ARBU 121
BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
STORM
DRAINAGE
SYSTEMS
UNIVERSITY OF SAINT ANTHONY
COLLEGE OF ENGINEERING & ARCHITECTURE
INSTRUCTOR: AR. ALVIRIE CLAIRE A. BERMEJO-UVERO, UAP, RMP, LPT
GENERAL REGULATIONS

2. ARBU 121
OVERVIEW
INTRODUCTION TO STORM DRAINAGE WATER SYSTEM
GENERAL PARTS OF THE DRAINAGE SYSTEM
DRAINAGE DRAINS, TRAPS AND VENTS
TRAP ARM, FIXTURE DRAIN, FIXTURE BRANCH AND
HORIZONTAL BRANCH
DRAINAGE PIPING
BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS

3. ARBU 121
INTRODUCTION TO STORM
DRAINAGE WATER SYSTEM
INTRODUCTION TO STORM
DRAINAGE WATER SYSTEM

4. Includes all the piping within the
public and private premises which
conveys sewage or other liquid
wastes to a legal point of disposal but
does not include the mains of a public
sewer system or a public sewage
treatment or disposal plant. Sec.
205.10 NPC 1999
INTRODUCTION TO STORM DRAINAGE WATER SYSTEM
BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121
DRAINAGE
SYSTEM

5. It is composed of:
Sanitary Drainage System – the pipings that convey the discharge of water closets or fixtures
having similar functions (containing fecal matter) with or without the discharges form other fixtures.
Waste Drainage System –the pipings that receive the liquid discharge from plumbing fixtures,
other than water closets and urinals, and are free of fecal flow.
Vent System –the pipings installed to provide a flow of air to or from a drainage system or to
provide a circulation of air within such system to protect trap seals from siphonage or back
pressure.
Storm Drainage System – the piping system that receives clear water drainage from leaders,
downspouts, surface run-off, ground water, subsurface water, condensate water, cooling water or
other similar discharges and conveys them to the point of disposal. All sanitary waste must be
excluded.
INTRODUCTION TO STORM DRAINAGE WATER SYSTEM
BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121
What comprises the DRAINAGE SYSTEM?
THE DRAINAGE SYSTEM IS OFTEN KNOWN AS THE DWV SYSTEM OR DRAINAGE, WASTE AND VENT SYSTEM

6. Harvested rainwater can provide a source of
alternative water to federal facilities. Alternative
waters are sustainable sources of water, not
supplied from fresh surface water or groundwater,
that offset the demand for freshwater. Rainwater
harvesting captures, diverts, and stores rainwater
from rooftops for later use. With additional filtration
and disinfection, harvested rainwater can also be
treated to potable standards to supplement
municipal potable water supplies to facilities.
INTRODUCTION TO STORM DRAINAGE WATER SYSTEM
BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121
RAINWATER
SYSTEM

7. ARBU 121
GENERAL PARTS OF
THE DRAINAGE SYSTEM
GENERAL PARTS OF
THE DRAINAGE SYSTEM

8. Parts of a Drainage System
Interceptors
Sumps and Ejectors
Backwater Valves
Roof and Floor Drains
SPECIAL DEVICES:
BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121
House Sewer
House Drain
House Trap
Fresh-air inlet
Soil and Waste Stacks
Fixture Branches
Traps
Vents
ESSENTIAL
COMPONENTS:
– It extends from the
public sewer to the
private sewage-
disposal tank to the
wall of the structure
and is entirely outside
the building
House Sewer

9. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121

10. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121

11. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121

12. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121

13. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121

14. ARBU 121
DRAINAGE DRAINS,
TRAPS AND VENTS
DRAINAGE DRAINS,
TRAPS AND VENTS

15. A Drain is a pipe, which carries ground and
surface waters, storm water or wastewater
into a building drainage system.
The common types of drains are the floor
drains and the roof drains.
The 2 types of drain connections are the
direct drain connection and the indirect
drain connection.
BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121
DRAINAGE DRAINS, TRAPS AND VENTS
What is a Drain?

16. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121
Floor
Drains
DRAINAGE DRAINS, TRAPS AND VENTS

17. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121
Roof
Drains
DRAINAGE DRAINS, TRAPS AND VENTS

18. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121
Roof Drains
DRAINAGE DRAINS, TRAPS AND VENTS
In plumbing, a pipe installed to
drain water from the roof gutters
or roof catchment to the storm
drain or other means of disposal.
Also called a conductor,
downspout, or roof drain.
WHY ROOF
DRAIN IS
IMPORTANT?
A roof drainage system is a
crucial component of any
house's structure. It is
responsible for directing
water away from the roof
and into the gutter system,
keeping the house dry and
protected from water
damage.

19. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121
DRAINAGE DRAINS, TRAPS AND VENTS

20. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121
DRAINAGE DRAINS, TRAPS AND VENTS
TYPES OF ROOF DRAINS

21. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121
DRAINAGE DRAINS, TRAPS AND VENTS
1. Conventional Gutters
The typical pitched roof can usually use gravity for all drainage purposes. On a pitched roof,
water simply glides off and into gutters, which direct water into an underground drainage
system. This roof drain option is simple, inexpensive, keeps water from pouring all over the
place and provides sufficient protection for doors and windows. In addition, it helps avoid
water pooling around the property’s foundation.

22. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121
DRAINAGE DRAINS, TRAPS AND VENTS
2. Scuppers
Scuppers are popular for flat enclosed roofs, terraces and parapets. This type of roof drain
consists of small holes cut in the side of the roof so that the water can drain out. Metal or rubber
is typically used to flash the area around the hole so that water doesn’t cause damage. After
exiting the hole, scuppers typically connect to a downspout to direct the water to an
underground drainage system. In other instances, the scuppers protrude from the building and
allow the water to fall into a prepared space such as a gravel drainage area

23. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121
DRAINAGE DRAINS, TRAPS AND VENTS
3. Inner/Interior Drain
Also a popular option for flat roofs, an inner drain is a drain or drains in a slightly lower area of
the roof that connects to an interior pipe that leads to an underground drainage system.
These drains typically have screens or protective barriers to prevent debris from washing
down the pipe. Among the advantages of these drains is that there are no unsightly
downspouts and gutters seen from the outside of the building and that there’s little chance
that pipes will freeze.

24. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121
DRAINAGE DRAINS, TRAPS AND VENTS
4. Siphonic Drain
This sophisticated drain is designed to operate at full capacity, reducing the need for
downspouts and underground drainage pipes. The system essentially sucks water from the roof
into the system and keeps air from being drawn in, meaning that the pipes can handle more.
These systems work on flat and pitched roofs.

25. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121
DRAINAGE DRAINS, TRAPS AND VENTS
SECTION 1104:
1104.1 Vertical rainwater piping shall be sized with
accordance to Table 11-1 which is based upon maximum
depth in mm of rainfall per hour falling upon a given
roof are per square meter.
Normally, a 102 mm/hour rainfall intensity is used in
MANILA AREA.
SIZING OF RAINWATER
PIPING

26. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121
Take Note:
Round, Square or
Rectangle rainwater
pipe may be used and
are considered
equivalent when
enclosing an inscribed
circle equivalent to
the dreain leader
diameter.

27. 1104.2 Where Vertical walls project above a roof so as to permit storm water to drain to adjacent roof are below,
the total roof area considered may be computed from Table 11-2 as follows;
1104.2.1 For one (1) wall - add fifty (50) percent of area of the wall to the roof area.
1104.2.2 For two (2) adjacent walls - add thirty five (35) percent of the total wall areas to the roof area;
1104.2.3 Two (2) walls opposite each other and of the same heights - add NO additional area to the roof area;
1104.2.4 Two (2) walls opposite of differing heights - add fifty (50) percent of wall area above top of lower wall
to the roof area.
1104.2.5 Walls on three (3) sides - add fifty (50) percent of area of the inner wall below the top of the lowest wall,
pluss allowance for area of the wall above top of the lowest wall per Section 1104.2.2 and 1104.2.4
1104.2.6 Walls of four (4) sides - no allowance of wall areas below top of lowest wall - add for areas above top
lowest wall per 1104.2.1, 1104.2.2, 1104.2.4, and 1104.2.5.
1104.2.7 The area of the side of a tall building exposed to rain is taken as one-half of the gross area. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121
DRAINAGE DRAINS, TRAPS AND VENTS
SECTION 1104.2:
Vertical Wall Areas

28. The size of a building rainwater piping of an of its horizontal branches shall be sized in accordance with
Table 11-2 (based upon maximum roof areas to be drained).
Example:
Table 11-2
Roof Area = 548.1 m²
Max Rainfall/hr. = 127 mm
Pipe Laid at (20.9 mm/m) slope or s = .02
Find area in column under 127 mm and at slope of .02 and read 561.1 m² (at closest).
Choose 152 mm as size of leader and downspout at leftmost column.
BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121
DRAINAGE DRAINS, TRAPS AND VENTS
SECTION 1104.3:
Horizontal Rainwater Piping

29. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121

30. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121

31. The size of semi-circular bottom roof gutters shall
be used based on the maximum roof area, in
accordance with Table 11-3
Example:
Table 11-3
Roof Area = 186 m²
Max Rainfall/hr. = 102 mm
Pipe Laid at 10.4 mm/m slope or s =0.01
Find area in column under 103 mm rainfall intensity
on Table 11-3 with s = .01 and read 181.4 m² (as
closest) move to left and read 177.8 mm diameter
gutter.
BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121
DRAINAGE DRAINS, TRAPS AND VENTS
SECTION 1104.4:
Roof Gutter
If the rainfall is more or less than those shown in
Table 11-2 and 11-3, then Adjust the figures in the
50.8 mm rainfall by multiplying by two (2) and
dividing by the maximum rate of rainfall in
mm/hr.
Example:
In Table 11-2 with a 10.4 mm/m or s = .01 and a
203.2 mm rainfall, find the number of square meter
a 102 mm pipe diameter will carry.
Solution : 2 x 349.3 = 87.4 m²
8
SECTION 1104.5:

32. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121

33. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121

34. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121
Note : Gutter has semi-circular bottom. Depth of equivalent of area of rectangular
gutter = 0.392 x diameter.

35. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121
Notes:
• The sizing data for vertical conductors, leaders and drains is based on the pipes flowing 7/24 full.
• For rainfall rates other than those listed, Determine the allowable roof area by diving the area given in the 25 mm/hr
column by the desired rainfall rate.
• Vertical piping may be round, square, or rectangular. Square type should be size to enclose its equivalent round pipe.
Rectangular pipe 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 3-1 .

36. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121

37. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121
Note: Width of Rectangular Gutter = 0.8862 x Diameter

38. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121

39. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121

40. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121
Indirect
Drain
DRAINAGE DRAINS, TRAPS AND VENTS

41. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121
DRAINAGE DRAINS, TRAPS AND VENTS

42. A Trap is a fitting or device designed and constructed to provide, when properly
vented, a liquid seal which prevents the backflow of foul air or methane gas
without materially affecting the flow of sewage or wastewater through it.
The types of waterseal traps are:
1. P-trap is the most widely used for fixtures, common diameter sizes are 110mm
(4”), 63mm (2”), 32mm (1-1/4”) and 38mm (1-1/2”).
2.Drum trap is used mostly for bathtubs. It has the advantage of containing a larger
volume of water & discharging a greater volume of water than a P-trap.
3.Grease Interceptor / Grease Trap - is an interceptor of at least 3 cubic meter
capacity to serve one or more fixtures and which is remotely located. Grease trap
is a device designed to retain grease from one to a maximum of four fixtures.
4. House Trap/Running trap - a device installed to prevent circulation of air
between the drainage of the building and the building sewer.
BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121
DRAINAGE DRAINS, TRAPS AND VENTS
What is a Trap?

43. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121
DRAINAGE DRAINS, TRAPS AND VENTS
Waterseal
Trap

44. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121
DRAINAGE DRAINS, TRAPS AND VENTS

45. ARBU 121
TRAP ARM, FIXTURE
DRAIN, FIXTURE BRANCH
AND HORIZONTAL BRANCH
TRAP ARM, FIXTURE
DRAIN, FIXTURE BRANCH
AND HORIZONTAL BRANCH

46. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121TRAP ARM, FIXTURE DRAIN, FIXTURE BRANCH AND HORIZONTAL BRANCH
TRAP ARM
Each fixture trap shall have a protecting vent so located
that the developed length of the trap arm from the trap
weir to the inner edge of the vent shall be within the
prescribed distance, but in no case less than two times
the diameter of the trap arm.

47. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121TRAP ARM, FIXTURE DRAIN, FIXTURE BRANCH AND HORIZONTAL BRANCH
Fixture
Drain

48. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121TRAP ARM, FIXTURE DRAIN, FIXTURE BRANCH AND HORIZONTAL BRANCH
Fixture
Branch

49. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121TRAP ARM, FIXTURE DRAIN, FIXTURE BRANCH AND HORIZONTAL BRANCH
Horizontal
Branch

50. ARBU 121
SPECIAL DEVICESSPECIAL DEVICES

51. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121SPECIAL DEVICES
GREASE
TRAP
–a device designed
to retain grease from
one to a maximum of
four fixtures

52. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121SPECIAL DEVICES
GREASE TRAP
When waste pretreatment is required, an approved
–type grease trap complying with the Code shall be
installed in the wasteline leading from sinks, drains
and other fixtures or equipment in establishments
such as restaurants, cafes, lunch counters,
cafeterias, bars and clubs, hotel, hospitals
sanitarium, factory or school kitchens, or other
establishments where grease may be introduced
into the drainage or sewer system in quantities that
can effect line stoppage or hinder sewage
treatment or private sewage disposal.
A grease trap is not required for individual dwelling
units or for any private living quarters.

53. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121SPECIAL DEVICES
Each plumbing fixture or
piece of equipment
connected to a grease trap
shall be provided with an
approved type Flow Control
or restricting device installed
in a readily accessible and
visible location in the
tailpiece or drain outlet of
each such fixture.
Flow control Devices shall be
so designed that the flow
through such device or
devices shall at no time be
greater than the rated
capacity of the grease trap.

54. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121SPECIAL DEVICES
GREASE
TRAP

55. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121SPECIAL DEVICES

56. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121SPECIAL DEVICES

57. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121SPECIAL DEVICES
Sump
Pump

58. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121SPECIAL DEVICES
BACKWATER
VALVE or NON-
RETURN VALVE
SEWAGE EJECTOR

59. ARBU 121
DRAINAGE PIPING DRAINAGE PIPING

61. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121
DRAINAGE PIPING

62. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121
DRAINAGE PIPING

63. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121
DRAINAGE PIPING

64. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121
DRAINAGE PIPING

65. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121
DRAINAGE PIPING

66. BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121
DRAINAGE PIPING

67. THANK YOU
for listening, Future Architect :)
BUILDING UTILITIES 1: PLUMBING AND SANITARY SYSTEMS
ARBU 121
REFERENCES:
REVISED PLUMBING CODE OF THE PHILIPPINES
SCRIBD. (N.D.). MODULE 13A - DRAINAGE SYTEM DISCUSSION. SCRIBD.
HTTPS://WWW.SCRIBD.COM/DOCUMENT/719700604/MODULE-13A-DRAINAGE-SYTEM-
DISCUSSION