(1) Service-pipes and circulating or supply-pipes for hot water shall be made of lead, galvanized steel or copper:

Provided that –

i) Piping of other materials may be used with the prior written permission of the local authority; and

ii) Service-pipes for cold water and not used in any position which, in the opinion of the local authority, is exposed, may be made of asbestos-cement or black polythene piping to the requirements of C.A.S. 177 or of U.P.V.C. piping to the requirements of C.A.S. No. K21.

(2) All steel water-pipes shall comply with the requirements of C.A.S. 102 or B.S. 1387 for medium or heavy-duty tubes, and the thickness of such pipes used in any particular service shall be not less than as specified in C.A.S. 102 or B.S. 1387 for the appropriate working pressure indicated by the local authority for the locality concerned.

(3) All steel water-pipes shall be galvanized or, where the diameter of the pipes is large enough to permit of other types of protection, shall be otherwise protected against corrosion, to the satisfaction of the local authority.

(4) Lead water-pipes shall comply with the relevant requirements of B.S. 602, Lead and lead alloy pipes for other than chemical purposes.

(5) Copper water-pipes shall comply with the requirements of S.A.B.S. 460, Copper and copper alloy tubing.

(6) The diameters of piping referred to in these by-laws relate to nominal internal diameters.

(7) No service-pipe shall be less than 12,5 millimetres in diameter.

(8) Pipework must be adequately sized to serve all outlets at all times.