SECTION 9

PLUMBING

Contents

901 SCOPE

902 GENERAL REQUIREMENTS

902.1 Prohibited Fittings and Connections

902.2 Dead Ends
902.3 Changes in Directions
902.4 Supports and Hangers

903 SOIL AND WASTE PIPES

903.1 General
903.2 Pipe Materials
903.3 Pipe Sizes
903.4 Fixture Unit Ratings
903.5 Workmanship
903.6 Gradients and Self Cleaning Velocities
903.7 Joints and Connections

904 PLUMBING FIXTURES

904.1 General
904.2 Water Closets
904.3 Flushing Cisterns
904.4 Lavatory Basins/Sinks
904.5 Shower Baths
904.6 Drinking Fountains
904.7 Traps
904.8 Water Seals
904.9 Clean-outs
904.10 Venting Systems
904.11 Floor Drains
904.12 Number of Sanitary Fixtures Required

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905 PIPES UNDER FLOORS AND WALLS

Table 9-1 Capacity of Pipes in Fixture Units

Table 9-2 Fixture Unit Ratings

Table 9-3 Minimum Sizes of Traps

Table 9-4 Number of Sanitary Facilities Required for

Employees

Table 9-5 Minimum Requirements for Sanitary Facilities for

General Use

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 SECTION 9

PLUMBING

901 SCOPE

This section sets out the requirements for plumbing and

drainage in buildings and the disposal of waste to a
septic tank or main sewer where this exists.

902 GENERAL REQUIREMENTS

902.1 Prohibited fittings and connections

a) No soil or waste pipe shall be fitted with double

hubs, double tees or double y's (without an
access door).

b) No waste pipe shall discharge into a bend

attached to a water closet bowl.

902.2 Dead Ends

a) Wherever a dead end exists or is proposed for a

soil or waste system it shall be laid so as to
prevent any accumulation of waste.

b) All unconnected openings in a drainage system

with the exception or a vent pipe shall be properly
capped so as to be both air and water tight.

902.3 Changes in Direction

a) All horizontal changes in direction of soil or waste

pipes shall be provided with an accessible
inspection chamber or clean out.

b) 22-1/2 degree bends and sanitary tees should be

used for changes in direction of flow in the
horizontal plane.

c) Bends, tees, y's and crosses may be used to effect

changes in direction in vent and water distribution
pipes.

902.4 Supports and Hangers

a) All vertical piping shall be supported, anchored

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 and adequately fixed with spacing not exceeding
5 feet.

b) All horizontal piping shall be supported, anchored

and adequately fixed to prevent sagging at each
hub. For cast iron and copper piping, this shall be
at 6 foot intervals, and for PVC and pitch fibre
piping through-out its length.

c) Pipe hangers shall be fixed to stone, brick work,

block work or concrete by means of expansion
type plugs.

d) Hangers shall be of the same material as the pipe,

or if of different material be insulated at areas of
contact with the pipe to prevent electrolysis.

e) Drains laid in unstable ground shall be adequately

supported so as prevent fracture of the pipe or
loosening of the joints in the event of ground
movement.

903 SOIL AND WASTE PIPES

903.1 General

Soil and waste pipes shall be located and fixed in

accordance with the following requirements:

(a) Branch pipes shall be located to provide for

drainage of sanitary fixtures into vertical stacks or
directly into manholes.

(b) Vertical stacks shall be located to provide for

drainage from branch pipes directly to manholes.

(c) Connections to pipes shall be located to prevent

cross flow from one connection to the other.

(d) Connections to pipes and between pipes shall be

made in direction of the flow.

(f) Open ends shall terminate not less than one foot
above the building eaves level nor less than three
feet above the head of any window ten feet away
or less and shall be protected with a wire balloon
of durable material.

(g) Pipes shall be fixed with suitable brackets or

straps and at a minimum distance of 6 inches

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 from the wall surface. At least one fixing shall be
provided for each unit length of pipe.

(h) Sufficient cleaning eyes and access points shall

be provided to enable all pipe work to be cleaned
by rodding. They shall be located to allow proper
clearance for the easy entry of cleaning roads and
be provided with suitable tight covers.

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903.2 Pipe Materials

a) Generally these shall be of suitable material, hard,

smooth, impervious and non-corrosive, such as
copper, PVC, cast iron or other material which
may be approved by the Authority if there is
evidence that the material is suitable.

b) Black iron, galvanised iron or concrete pipes are

not recommended for use as soil pipes.

903.3 Pipe Sizes

a) The diameter of pipes shall be consistent with the

maximum load, but soil pipes shall not be less
than 3 inches in diameter.

b) Waste water pipes shall not be less than 1-1/4

inches in diameter.

c) Table 9-1 establishes the maximum fixture unit

load permitted for a given size of waste pipe
under various conditions and shall be used to
determine the required size of waste or soil pipe
provided that:

(1) The total unit load on the pipe is calculated from Table 9-
2.

(2) Not more than one WC shall be connected to any one 3"
diameter soil pipe.

(3) No branch pipe shall be smaller than the size of the

fixture trap that it serves.

(4) No vertical stack shall be smaller than the largest branch

pipe that it serves.

(5) The gradient of a branch pipe shall be not less than 1 in

48.

(6) Not more than 4 WCs shall be connected to a branch pipe

of diameter less than 4 inches with a gradient less than 1
in 12.

(7) Not more than 4 WCs shall be connected to any 3" diam-
eter branch pipe or vertical stack.

(8) Not more than 50% of the maximum discharge unit load
permitted for vertical stacks serving more than 2 storeys
shall be discharged into the stack from any one branch

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 pipe or in any one storey height.

903.4 Fixture Unit Ratings

Table 9-2 establishes the relative load value of various fixture units and
shall be used in determining the required size of pipes for the fixtures
being served.

903.5 Workmanship

a) All plumbing shall be installed in a workmanlike manner.

b) After laying, soil and ventilating pipes shall be capable of with-

standing smoke or air tests under pressure, have no bends,
except where unavoidable, in which case bends shall be as
obtuse as possible so as not to reduce the internal diameter of
the pipe.

c) Soil/waste pipes shall not discharge effluent so as to cause

dampness to any foundation or wall of a building.

903.6 Gradients and Self Cleaning Velocities

a) Soil pipes shall be laid at a minimum gradient of 1:48 for 4 inch

pipes and 1:60 for 6 inch pipes.

b) Waste pipes shall be laid at a minimum gradient of 1:30.

c) Self cleaning velocities would be achieved if velocities are

approx. 2.5 feet per second with the pipe flowing 1/4 full.

903.7 Joints and Connections

a) All joints and connections shall be of the same material as the

main pipe and shall be air and water tight. They shall be con -
structed so as to allow the free flow of waste, and before
commissioning, be swabbed and cleaned inside to avoid
obstructions of the bore.

b) In joining soil pipes the spigot or plain end of the pipe shall be
laid in the direction of the flow or downstream.

c) Joints to soil pipes shall be as follows:

i) for lead - wiped or burned.

ii) for cast iron - socket made with hemp or yarn and
metallic lead properly caulked.

iii) for pitch fibre - tapered couplings.

iv) for PVC - with a suitable rubber joint fitting or welded with

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 solvent cement.

v) for vitrified clay/salt glazed ware - socket made with

tarred hemp or gasket and the remaining space filled
with cement/sand mixture.

d) No coating or paint shall be applied before testing.

e) Where waste pipes are connected to soil pipes, all pipes are to
be constructed in the same way as specified for soil pipes.

904 PLUMBING FIXTURES

904.1 General

Generally these shall be of smooth, hard, durable impervious and

corrosion resistant materials free from flaws and blemishes.

904.2 Water Closets

a) Water closet bowls shall be of vitreous china, vitreous glazed

earthenware or other suitable material.

b) Water closet bowls shall be attached to the floor and/or wall and
be fitted with a seat of smooth non-absorbent material.

c) The use of a separate well flushing system will reduce the use of
fresh water from the cistern. All components of the salt water
system shall be plastic or other suitable material non-corrosive.

904.3 Flushing Cisterns

Water closet systems shall have flush valves which are easily accessible
for repairs, and flush pipes of not less than 1-1/4 inches in diameter.
When low level cisterns are used, larger flush pipes are necessary.

904.4 Lavatory Basin/Sinks

a) The top edge of every lavatory basin or sink shall be fixed at a

height above finished floor level suitable for the persons using
the fixtures.

b) Fixtures for special use, such as for handicaps and for

children, shall be mounted at the appropriate height for
the particular application.

c) Every lavatory basin shall be provided with an overflow,

connected to the building or inlet side of the trap.

904.5 Shower Baths

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 Shower and tub outlets must be not less than 1-1/2 inches in diameter
and be fitted with removable strainers. Shower outlets are normally 2".
The use of "water saver" shower heads is encouraged.

904.6 Drinking Fountains

Drinking fountains shall have orifices located above the highest

overflow level of the receptacle and be shielded so that the drinker
cannot put his/her lips on the orifice.

904.7 Traps

a) Traps forming an integral part of plumbing fixtures shall be

supplied with the fittings to which they are to be attached.

b) All fixtures connected to foul drainage shall be trapped as

closely as possible to the fixture outlet.

c) No trap with partitions shall be used, and crown venting off the
upper curve of an "S" trap is not permitted as this results in
accumulations in the vent.

904.8 Water Seals

All traps shall have a minimum water seal of 3 inches for soil and 2
inches for waste and be not less than 3 inches diameter for soil fixtures
and 1-1/4 inches for waste water.

904.9 Clean-outs

Every clean-out shall be equal in wall thickness to that of the pipe, be

readily accessible, shall open opposite to the direction of flow or at right
angles to it, and shall provide adequate space for cleaning.

904.10 Venting Systems

a) All water closets shall have a vent pipe of not less than 1-1/2
inches in diameter. Vent pipes shall also be used when two or
more waste fittings are connected to a soil or waste pipe.

b) Vent pipes shall be installed in accordance with 903.1(f) or

extend to a greater distance as may be prescribed by the
Director for unusual situations such as roof gardens. Vent pipes
shall be connected above the flood level rim of the highest
fixture served and graded to drip back to the soil or waste pipe.

c) Venting systems shall be in accordance with the National

Plumbing Code approved by the American Standards Association
ASA A 40-8-1955 or any other Code approved by the Authority.

d) Flashings at vent terminals shall be water tight. Vents shall

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 preferably be fitted with a wire cage so as to permit free
passage of air.

e) Drains shall be ventilated to prevent the accumulation of foul air

and to maintain equal pressure inside and outside the system.

904.11 Floor Drains

Floor drains connected to sanitary sewers shall be equipped with extra

deep traps to prevent the seal from drying out. Drains in seldom used
areas shall be equipped with an automatic filling device to keep the
trap filled with water.

904.12 Number of Sanitary Fixtures Required

Tables 9-4 and 9-5, shall determine the minimum number of sanitary
fittings required in a building provided that:

a) Where separate facilities are required for employees and public

use the total number of persons to be provided for shall be
proportioned on the most realistic basis possible.

b) The number of public facilities to be provided by drive in

cinemas, drive-in restaurants or similar establishments shall be
based on 3 persons for each parking bay.

c) For any residence or apartment the minimum provision shall be l

water closet (WC), l lavatory basin and 1 bath or shower and 1
sink or tub.

d) For any building providing sleeping accommodation the

minimum provision shall be l WC, l lavatory basin and 1 bath or
shower for each 10 beds or each 10 persons accommodated.

e) For any building where the use or occupancy involves the

employment of staff, facilities shall be provided for employees in
accordance with Table 9-4 except that where the total number of
employees is less than 10 the minimum provision shall be for 1
WC and 1 L.B. serving both sexes where facilities are accessible
only through private offices and shall be additional to the
required minimum provision.

f) Where facilities for the public are required they shall be

additional to and separate from facilities required for employees,
and shall be provided and maintained in clean condition in
accordance with Table 9-5 for:

(i) Any place of public assembly as defined in Section 2 of

this Code.

(11) Any building or part of a building where the major use or

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 occupancy is the regular provision of food or drink for
consumption by the public on the premises or on drive -
in service system.

(111) Any shop, store or market with more than 5,000 sq.ft of
sales area.

(iv) Any building providing more than 500 sq.ft of public

waiting space.

(v) Gas stations with 4 or more service pumps.

(g) In any building of Group A,B,D,E,(b) and E(c) (Table 3-1) of more
than 5,000 sq.ft. in total area, at least one cleaner's sink shall be
provided for each floor of more than 2,500 sq.ft in area.

(h) For buildings of Group B such additional facilities shall be

provided as may be required by the Chief Environmental Health
Officer.

(i) For buildings of Group C such additional facilities shall be

provided as may be required by the Chief Environmental Health
Officer.

(j) For schools, colleges or other educational buildings such addi-

tional facilities shall be provided as may be required by the Chief
Environmental Health Officer.

(k) Except for private residences a minimum of one facility for male
and one for female shall be provided for persons with disability.

905 PIPES UNDER FLOORS AND WALLS

a) No part of a drain shall be laid under a building unless approved

by the Authority.

b) Where a drain is laid under a floor, not being a suspended floor,

it shall be laid in a straight line for its entire length beneath the
building. But in no case shall the drain under the building be
longer than 40 ft.

c) Where drains are laid on piers, care must be taken to ensure that
the piers are on sound foundation and be spaced not more than
eight feet apart.

d) Rodding and flushing eyes shall be easily accessible, shall open

opposite to the direction of flow, and adequate space for rodding
and flushing shall be provided.

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 Table 9-1

Capacity of Pipes in Fixture Units

Size of pipe (diam- Each horizontal Each vertical stack Each vertical stack
eter in inches) branch (capacity) serving 2 storeys serving more than
in height 2 storeys in height
1 - 1/4 1 2 -

1 -1/2 4 4 -

2 8 10 20

2 - 1/2 12 20 40

3 24 30 60

4 200 240 500

5 400 540 1,100

6 800 960 1,900

Table 9-2

Fixture Unit Ratings

Description of Fixture Unit Rating Description of Fixture Unit Rating

Bathtub (with or without shower) 2 Lavatory basin (over 1-1/4" 2
trap)

Bidet 2 Showers (per shower head) 2

Drinking fountain 1 Urinal (flush valve operated) 6

Flushing sink (cistern operated) 3 Water closet (cistern operated) 4

Floor Drain 3 Water closet (flush valve 6

operated)

Kitchen sink (up to 1-1/2" trap) 1-1/2 Washing machine (domestic) 4

Kitchen sink (commercial) 2 Continuous flow fixture for 2

each gal. per min.

Laundry tub 2 Unspecified to 2" trap or drain 3

Lavatory basin (up to 1-1/4" trap) 1 Unspecified to 3" drain or tap 5

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 Table 9-3.

Minimum Sizes of Traps (inches)

Bathtub 1-1/2 Shower (with accessible trap) 1-1/2

BIdet 1-1/2 Shower (with concealed trap) 2

Drinking fountain 1-1/4 Shower stall (2 to 4 heads) 2-1/2

Flushing sink 3 Shower stall 5 to 12 heads 3

Floor drain 3 Shower stall (over 12 heads) 4

Kitchen sink 1-1/2 Urinal 2

Kitchen sink (commercial) 2 Water closet (siphonic action) 3

Laundry tub 1-1/2 Water closet (wash down bowl) 3-1/2

Lavatory basin (domestic) 1-1/2 Washing machine 1-1/2

Lavatory basin (commercial) 1-1/2

Table 9-4

Number of Sanitary Fixtures Required for Employees

Number of employees WCs Urinals Lavatory Showers

basins
1 -10 1 - 1 -

11 - 30 1 1 2 -

31 - 45 2 1 3 1

46 - 90 2 2 4 1

91 - 120 3 3 6 1

121 - 150 4 3 7 2

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 Table 9-4 (Cont'd)

Number of Sanitary Fixtures Required for Employees

Number of employees Showers WCs Lavatory

basins
1 - 10 1 1 1

11 - 30 1 2 2

31 - 45 2 3 3

46 - 90 2 4 4

91 - 120 2 6 6

121 - 150 2 7 7

Table 9-5

Minimum Requirements for Sanitary Facilities

Number WCs Urinals Lavatory basins

1 - 30 1 1 1

31 - 120 2 2 1

121 - 240 3 3 2

241 - 360 4 3 3

361 - 480 4 4 4

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 Table 9-5 (Cont'd)

Minimum Requirements for Sanitary Facilities

Number WCs Lavatory basins

1 - 15 1 1

16 - 30 2 2

31 - 120 4 3

121 - 240 5 3

241 - 360 6 3

Number WCs Urinals Lavatory basins

1 - 30 1 - 1

31 - 60 1 1 2

61 - 90 2 2 2

91 - 120 3 3 3

120 - 180 3 3 3

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 Table 9-5 (Cont'd)

Minimum Requirements for Sanitary Facilities

Number WCs Lavatory basins

1 - 15 1 1

16 - 30 2 1

31 - 60 2 2

61 - 90 3 2

91 - 120 4 3

121 - 180 5 3

Area of sales space in square feet Number of fixtures

1,000 - 10,000 1 WC
1 Lavatory basin

10,000 - 15,000 1 WC
1 Urinal
1 Lavatory basin

15,000 - 20,000 2 WCs

1 Urinal
1 Lavatory basin

Over 20,000 2 WCs

2 Urinal
2 Lavatory basins

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 Table 9-5 (Cont'd)

Minimum Requirements for Sanitary Facilities

Area of sales space in square feet Number of fixtures

1,000 - 10,000 1 WC
1 Lavatory basin

10,000 - 15,000 2 WCs

1 Lavatory basin

15,000 - 20,000 3 WCs

2 Lavatory basins

Over 20,000 4 WCs

2 Lavatory basins

Equipment Fixtures
2 or more pumps 1 WC
1 Lavatory basin

Equipment Fixtures
2 or more pumps 1 WC
1 Lavatory basin

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