Hong Kong Regulations

BUILDING (STANDARDS OF SANITARY FITMENTS, PLUMBING, DRAINAGE WORKS AND LATRINES) REGULATIONS - REGULATION 47

Laying of drains and sewers

(1) All drains and sewers (except drains provided for the carriage of
sub-soil water) and traps shall be firmly laid on a bed of concrete not less
than 100 mm in thickness and at least 150 mm wider than the diameter of the
pipe or trap, and shall be haunched with concrete so that the full width of
the bed is carried up to the level of the horizontal diameter of the pipe and
from that point splayed up on both sides of the pipe from the full width of
the bed to meet the pipe barrel tangentially. (L.N. 294 of 1976)

(2) All drains and sewers shall be supported along the full length of the
barrels and not by the sockets.

(3) Where any drain or sewer is laid in soft and yielding ground-

   (a)  adequate support shall be provided for such drain or sewer; and

   (b)  save where the same are provided for the carriage of sub-soil  water,
        the pipes shall be completely surrounded by at least 100 mm of
        concrete. (L.N. 294 of 1976)

(4) Cast iron pipes above the ground may be carried on adequate piers or other
sufficient supports, if such support is provided at each joint.