2356

THE NEW ZEALAND GAZETTE.

[No. 67

(iii.) It shall have a water-seal of not less than 2 in.
(iv.) It shall have a cleansing-screw or other approved method of access and cleansing.

(c.) The waste-pipe shall be connected to the bath, basin, sink, or other appliance by means of a brass cap and lining so fitted as to form a watertight joint, and if the trap be of lead such trap shall be wiped to the lining.

In the case of a washtub made of wood, the connection may be made by tafting the end of the waste-pipe or trap over a rebate round the outlet of the tub on its inner surface, in such manner that a flange wiped to the waste-pipe or trap is pressed firmly against the under surface of the tub. The connection shall be finished by fixing with screws the seating of the plug into the rebate in a bedding of red-lead putty.

Ventilation of waste-pipes.

(f.) Waste-pipes shall be ventilated as follows :—

(i.) Every waste-pipe receiving the discharges from two or more appliances shall be extended upwards as a vent-pipe herein referred to as “the main vent,” on the outside of the building, in as direct a line as possible from above the highest branch waste-pipe to a level at least 3 ft. above the eaves or parapet of the building, and capped with a wire top or cowl.

Main vents.

(ii.) Such main vent shall be made of lead, galvanized wrought iron, or cast iron, and shall be of the same diameter as the main waste-pipe so ventilated.

(iii.) Every branch waste-pipe joining a main waste-pipe shall be separately ventilated by a vent-pipe to be known as the “back vent” joining the waste-pipe on the side of the trap furthest from the appliance, and as near the trap as practicable, and such back vents shall be of the same material as, and not less than two-thirds of the diameter of the waste-pipe it ventilates: Provided that in any case no back vent shall be less in diameter than 1 ¼ in.

Back vents for waste-pipes.

(iv.) Two or more back vents may be combined and carried up as a single vent-pipe, and such combined vent shall be of the material specified for main vents and of a diameter not less than that of the largest branch waste so ventilated, and may be carried up to a point 3 ft. above the parapet or eaves of the house, or may be connected to the main vent at a point above the level at which the highest branch waste-pipe connection joins the main waste-pipe.

(v.) Subject to the next succeeding paragraph, any waste-pipe which joins the main waste-pipe at a higher level than every other branch waste-pipe need not be provided with a back vent.

(vi.) If any waste-pipe from a single appliance is less than 10 ft. in length, and shows no tendency to siphon the water-seal of its trap, such waste need not be ventilated, but in all other cases a back vent shall be provided joining the waste-pipe from single appliances as near the trap as practicable, and conducted by the shortest route to the open air to terminate in an approved manner not less than 3 ft. from any windows.

(g.) Wherever practicable waste-pipes and their traps and vent-pipes shall not be covered in by woodwork or otherwise, but where such covering is not avoidable it shall be fastened by screw-nails so as to be readily removed.

Wastes from washtubs.

(h.) In respect to the waste-pipes of washtubs, if such washtubs are placed on the ground floor of a detached building the waste-pipe need not be trapped if less than 6 ft. in length, in all other cases the waste-pipes of washtubs shall be trapped and ventilated as provided for the waste-pipes of other sanitary appliances:

Provided that where the waste-pipes of not more than three washtubs are combined to form one waste-pipe, and such combined waste-pipe is trapped, it shall not be necessary to provide also separate traps for the waste-pipe of each washtub.