3310
THE NEW ZEALAND GAZETTE.
[No. 81

breach or non-observance of any such condition as aforesaid shall be an offence.

TRAPS.—DRAINAGE.

33. Traps of four (4) classes shall be used :—

(A.) Boundary or Disconnecting Traps.

On every connecting branch drain with the sewers at or near the boundary of the premises a boundary or disconnecting trap shall be fixed, with or without a chamber, as may be ordered by the Sanitary Inspector.

The traps shall be of round section and self-cleansing form, and of a diameter similar to the drain to which they are connected. They shall have an inspection-cap on the sewer side of the trap and an opening for the admission of fresh air and inspection purposes on the drain side of the trap, and a water-seal of 2½ in.

The openings shall be of the same diameter as the trap. They shall have a suitable base for level setting.

(B.) Gully-traps.

At the end of every branch or main drain receiving waste water other than is provided for in the two following clauses, a round section self-cleansing form of gully-trap must be fixed, having a 6 in. tapering inlet with a 4 in. outlet, a water-seal of not less than 2½ in., and provided with a base for level setting. The top of the trap shall be finished with a dish-block or curb fitted with a removable cast-iron bar grating having openings of suitable outlet-capacity. If dish-blocks are used, they shall have a spigot outlet for joining with the trap, and shall be 6 in. in depth from the top to the grating. If curbs are used, they shall be constructed of brick or concrete 4 in. thick, 6 in. deep, and not less than 12 in. square internally, plastered with cement mortar, and finished in such manner as to prevent water lodging in them. When it is desired to discharge waste-pipes below the grating, gully-traps, with side and back inlets of cast iron or earthenware hoppers, approved by the Sanitary Inspector, may be used.

(C.) Silt-traps.

On the terminals of branch drains receiving drainage from stables, manure-receptacles, yard, or other surfaces, or rain-water pipes, silt-traps shall be fixed. They shall be round in section, flat bottom, sealed 2½ in., and provided with trays fitted with handles for catching and removing silt. Similar provision of dish-blocks, curbs, and gratings shall be made for silt-traps as is specified for gully-traps.

(D.) Grease-traps.

On the terminals of branch drains receiving the discharges from kitchen and scullery sinks of hotels, boarding-houses, restaurants, clubs, or other buildings where, in the opinion of the Sanitary Inspector, such is necessary, approved grease-traps shall be fixed. These traps shall possess the following provisions :—

(1.) Constructed of impervious materials.

(2.) Of sufficient capacity.

(3.) Fitted with a tray with a handle for the removal of the silt and grease.

(4.) Provided with suitable covers and protective curbs.

SETTING OF TRAPS.

34. Where in the opinion of the Sanitary Inspector it is required, brick, stone, or concrete foundations shall be put in on which to set the traps.

VENTILATION OF DRAINS.

Fresh-air Inlets.

35. From the opening on the house side of the disconnecting-trap a shaft for the admission of air to the drains shall be carried to a point above ground and to the position which, in the opinion of the Sanitary Inspector, is the best suited to the conditions existing.

Where no special circumstances exist requiring other arrangements than those hereafter stated, fresh-air inlets shall be arranged to provide access to the disconnecting trap in the following manner: From the inlet opening on the trap a shaft shall be carried to a point at least 9 in. above ground-level; the terminating 18 in. of the shaft shall be a piece of 4 in. cast-iron pipe, ⅜ in. thick, fitted with a removable cast-iron dome top, having a diameter of 6 in., provided with support brackets and gun-metal set-screws for fixing. This cast-iron terminal pipe shall be connected with a cement joint to the earthenware pipe, and shall be surrounded at ground-level with a layer of concrete 4 in. thick and 4 in. wide, the surface to be cement plastered.

When it is necessary to fix the air-inlet at a distance from the trap, a junction pipe shall be inserted in the vertical access-shaft off the trap, and the air-inlet pipe carried from the junction branch to the required position, and the access-shaft shall be continued to a point 9 in. below or up to the ground-level as directed by the Sanitary Inspector, the end of the shaft being provided with a suitable stopper. When the access-shaft terminates at ground-level, the end shall be encased in a suitable cast-iron box or brick or concrete chamber provided with an iron plate, stone, or reinforced-concrete cover.

For chambers the fresh-air inlet shall be taken through the wall below the cover, and treated in a similar manner above ground as specified in preceding clause.

When it is necessary to carry the fresh-air inlet above head height the shaft above ground shall be continued in cast-iron pipe and provided with an approved terminal. Where necessary to prevent back rush of air through air-inlets, approved flap-valves shall be fixed.

Air-inlets shall be of similar size as the drain to which they are connected.

VENT-PIPES.

36. At or near the end of every main drain and branch drain 12 ft. or more in length a terminal ventilation-pipe shall be fixed.

Provided that where a soil-pipe can be utilized for drain-ventilation no other vent-pipe will be required on that portion of the drain. Such ventilation-pipes shall be not less in size than the diameter of the drain they ventilate, and shall be constructed of the materials and jointed in accordance with the specification hereto, except in cases where, in the opinion of the Sanitary Inspector, it is necessary the pipe, for the height of 6 ft. above ground-level, shall be of cast-iron pipe. In cartways or passages the ventilation-pipe shall, at the option of the Sanitary Inspector, be let into the wall or otherwise protected from likely damage by vehicular traffic.

Such vent-pipes shall be carried to a height 3 ft. above the eaves of the building to which they are attached, but in no case to a less height than 12 ft., unless affected by the following requirements :—

(1.) The outlet of the ventilation-shaft shall be placed as far as possible from chimneys, windows, or doors;

(2.) When the distance from a chimney is 6 ft. or under, the vent-pipe must terminate 2 ft. below the chimney opening;

(3.) When the outlet of the vent-pipe is less than 20 ft. from a window or door, then it must be carried up 6 ft. higher than the window or door opening within that radius, and have sufficient stays to support it.

Such vent-pipes shall be carried as direct as possible on the outside walls of a building, and where it is impracticable to fix them in line throughout their length, segment or lobster back bends or obtuse angles shall be used at each change of direction.

Such vent-pipes shall be properly supported and constructed, and all joints shall be airtight.

Such vent-pipes shall be provided with a galvanized-wire guard or cowl of approved pattern on the top thereof. When cast-iron pipes are used for the construction of vent-pipes, an approved rust-pocket shall be fixed at the foot of such pipes. The joint between the vent-pipe and drain shall be made by the licensed plumber.

NOTICE TO ALTER OR REMOVE VENT-SHAFTS.

37. If after a ventilation shaft have been erected, the same shall by reason of the erection of any new building or buildings, or the addition to or alteration of any building (including any building in respect whereof such shaft may have been furnished), or by reason of any other matter or thing, become or be in a position or in any other respect not in accordance with the foregoing section, it shall be lawful for the Sanitary Inspector, by notice in writing, signed by him, to require the owner of the premises upon which such shaft shall be erected to do within a stated time any reasonable acts or things to be specified or indicated in such notice, so as to cause such shaft to be in accordance with the foregoing section, or with any of the provisions of that section that may be referred to in that behalf in such notice; or by like notice to require such owner, within a stated time, to remove or alter the position of such vent-shaft in such manner and subject to such stipulations as may be set out in such notice. The Sanitary Inspector may from time to time renew any notice given under this section.

PLUMBERS’ WORK.

Works to be executed by Licensed Plumbers only.

38. It shall not be lawful for any person other than a licensed plumber, duly licensed under this part of this