Anti- syphonage pipes.
30. (1) Where-
Ventilating pripes.
12
(a) more than one trap of a watercloset fitment, urinal, slop sink?
or waste fitment is connected with one soil pipe; or
(b) more than one trap of a waste fitment is connected with on
waste pipe,
the traps shall be ventilated by means of anti-syphonage pipes:
Provided that if, in the case of waste fitments, the traps to such filments are constructed to prevent loss of water seal, it shall not be necessary to provide an anti-syphonage pipe, unless the Building Authority so requires.
(2) Every anti-syphonage pipe shall be connected with-
(a) the trap, if the connexion with the anti-syphonage pipe is an
integral part of the trap; or
(b) the branch soil pipe or branch waste pipe-
(i) on the side of the water seal nearest the main soil pip: or waste pipe; and
(ii) at a point not more than twelve inches from the trap! outlet.
(3) The internal diameter of every anti-gyphonage pipe shall-- (a) if the diameter of the soil pipe or waste pipe to which it is connected is three inches or more, be not less than two inches,
(b) if the diameter of such soil pipe or waste pipe is less than'
three inches, be not less than-
(i) two-thirds of the internal diameter of such soil pipe œ waste pipe: or
(ii) one and a quarter inches, whichever is the greater.
(4) (a) The main anti-syphonage pipe may be connected to a soil pipe which, under paragraph (3) of regulation 31, is acting is a ventilating pipe:
(b) every such connexion shall be made at a point above the flood
level of the highest fitment connected to the soil pipe.
31. (1) Every ventilating pipe for any drain or sewer shall be carried up to a height not less than three feet above the roof of the building to which it is fixed or, where such building has a pitched roof. above the eaves of such building.
(2) No ventilating pipo shall be so fixed as to permit the escap of foul air from any drain, sewer, soil pipe or waste pipe into an building.
19
(3) Soil pipes or waste pipes may be carried up to a suitable height above the building to which they are fixed to act as ventilating pipes for any drain or sewer.
(4) The internal diameter of every ventilating pipe and of every soil pipe or waste pipe which, under paragraph (3), is acting as a venti- lating pipe, shall be not less than three inches.
(5) The open end of every ventilating pipe shall be provided with a suitable grating having apertures of an aggregate area not less than the sectional area of the pipe.
water.
(6) Ventilating pipes shall not be used for the carriage of surface
32. (1) (a) Every rain water pipe which discharges to a drain Rain water which is connected to a public sewer provided for the carriage pipes.
of surface water shall discharge-
(i) not more than six inches above the level of the ground, over a suitable trapped gully: or
(i) into a trapped gully, below the level of the grating but above the level of the water in the trap.
(5) Every rain water pipe which discharges to a channel shall dis- charge at a height not more than six inches above the level of the top of the channel.
(c) Every rain water pipe which discharges, through a cast iron conductor, to the side channel in a street shall be provided, at the foot thereof, with a shoe so as to ensure that any surface water discharged from the pipe will discharge directly into the conductor.
(2) The number and size of rain water pipes provided for any building shall be calculated at the rate of one square inch of pipe to every bundred square feet of horizontal roofed-over surface.
(3) Save as provided in regulation 33, the diameter of every rain water pipe shall be not less than two and a half inches.
(4) Rain water pipes shall not be connected with any soil pipe. waste pipe or ventilating pipe.
(S) Where a rain water pipe discharges, across any footpath, to the side channel of a street, it shall discharge through a cast iron conductor.
33. (1) Any rain water pipe provided for the carriage of surface Rain water water from a verandah or balcony shall, where there is, at a suitable pipes for position, a rain water pipe provided for the carriage of surface water verandahs or from the roof of the building, be connected to such pipe.
balconies,