7.3.4.

(1) Piping shall be provided with support that is capable of keeping the pipe in alignment and bearing the weight of the pipe and its contents.

(2) Every floor or wall mounted water closet bowl shall be securely attached to the floor or wall by means of a flange and shall be stable.

(3) Every wall mounted fixture shall be supported so that no strain is transmitted to the piping.

(1) Piping, fixtures, tanks or devices shall be supported independently of each other.

(1) Where a hanger or support for copper tube or brass or copper pipe is of a material other than brass or copper, it shall be suitably separated and electrically insulated from the pipe to prevent galvanic action.

(1) Except as provided in Sentence (2), vertical piping shall be supported at its base and at the floor level of alternate storeys by rests, each of which can bear the weight of pipe that is between it and the rest above it.

(2) The maximum spacing of supports shall be 7.5 m.

(1) Nominally horizontal piping that is inside a building shall be braced to prevent swaying and buckling and to control the effects of thrust.

(2) Nominally horizontal piping shall be supported so that,

(a) galvanized iron or steel pipe is supported at intervals not exceeding,

(i) 3.75 m if the pipe size is 6 in. or more, and

(ii) 2 500 mm if the pipe size is less than 6 in.,

(b) lead pipe is supported throughout its length,

(c) cast iron pipe is supported,

(i) at or adjacent to each hub or joint,

(ii) at intervals not exceeding 3 m, and

(iii) at intervals not exceeding 1 000 mm if the pipe has mechanical joints and the length of pipe between adjacent fittings is 300 mm or less,

(d) asbestos-cement pipe is supported,

(i) at intervals not exceeding 2 000 mm or have two supports for every 4 m length of pipe, and

(ii) at intervals not exceeding 1 000 mm where the length of pipe between adjacent fittings is 300 mm or less,

(e) ABS or PVC plastic DWV pipe is supported,

(i) at intervals not exceeding 1 200 mm,

(ii) at the ends of branches,

(iii) at changes of direction or elevation, and

(iv) if the pipe is a fixture drain that is more than 1 000 mm in length, as close as possible to the trap,

(f) plastic water pipe is supported at intervals not exceeding 1 000 mm,

(g) copper tube and copper and brass pipe is supported at intervals not exceeding,

(i) 3 m if the tube or pipe is hard temper and larger than 1 in. in size,

(ii) 2 500 mm if the tube or pipe is hard temper and 1 in. in size or less, and

(iii) 2 500 mm if the tube is soft temper,

(h) aluminum DWV pipe is supported,

(i) at intervals not greater than 3 m,

(ii) at both sides of all joints,

(iii) at all branch ends,

(iv) at all points where there is a change in direction, and

(v) as close to all traps as possible,

(i) supports and hangers for aluminum DWV pipe shall have a broad support base and shall be free of burrs and rough edges to prevent abrasion of the pipe,

(j) where joints in the piping are less rigid than the pipe, the support points shall be selected so as to minimize the shear and bending forces imposed on the joints,

(k) PE/AL/PE or PEX/AL/PEX composite pipe is supported at intervals not exceeding 1 000 mm, and

(l) PP-R plastic pipe is supported,

(i) at intervals not exceeding 1 000 mm,

(ii) at the end of branches, and

(iii) at changes of direction and elevation.

(3) Where plastic pipe or a composite pipe incorporating a plastic component is installed,

(a) the pipe shall be aligned without added strain on the piping,

(b) the pipe shall not be bent or pulled into position after being welded or joined, and

(c) hangers shall not compress, cut or abrade the pipe.

(4) Reserved.

(5) Where hangers are used to support nominally horizontal piping they shall be,

(a) hangers with metal rods of not less than,

(i) 6 mm diam for supporting pipe 2 in. or less in size,

(ii) 8 mm diam for supporting pipe 4 in. or less in size, and

(iii) 13 mm diam for supporting pipe over 4 in. in size, or

(b) solid or perforated metal straps not less than, 

(i) 0.6 mm nominal thickness, 12 mm wide for pipe 2 in. or less in size, and

(ii) 0.8 mm nominal thickness, 18 mm wide for pipe 4 in. or less in size.

(6) Where a hanger is attached to concrete or masonry, it shall be fastened by metal or expansion-type plugs that are inserted or built into the concrete or masonry.

(1) Except as provided in Sentence (2), nominally horizontal piping that is underground shall be supported on a base that is firm and continuous under the whole of the pipe.

(2) Nominally horizontal piping installed underground that is not supported as described in Sentence (1) may be installed using hangers fixed to a foundation or structural slab provided that the hangers are capable of,

(a) keeping the pipe in alignment, and

(b) supporting the weight,

(i) of the pipe,

(ii) its contents, and

(iii) the fill over the pipe.

(1) Where a vent pipe terminates above the surface of a roof it shall be supported or braced to prevent misalignment.

(1) No compression fitting connecting to plain end pipe or tube shall be used in a plumbing system unless the pipe or tube and fittings are sufficiently stayed, clamped, anchored or buttressed so as to prevent separation during normal service of the system allowing for surge pressures.

(1) Pipe clamps and tie-rods, thrust blocks, locked mechanical or push-on joints, mechanical joints utilizing set screw retainer glands, or other suitable means of thrust restraint shall be provided at each change of direction of a water service pipe 4 in. or more in size and at all tees, plugs, caps and bends.

(2) Backing for underground water service pipes shall be placed,

(a) between undisturbed earth and the fitting to be restrained and shall be of sufficient bearing area to provide adequate resistance to the thrust to be encountered, and

(b) so that the joints will be accessible for inspection and repair.

(3) Concrete thrust blocks shall have a minimum compressive strength of not less than 10 MPa after 28 days.

(4) Thrust blocks shall not be used to restrain vertical pipe.