(1) Materials not provided for in these by-laws.- Subject to the provisions of section 7, building materials not provided for in these by-laws may be used in walling if they comply with the terms of a departure certificate or authorization granted in terms of Part VII of Chapter 2.

(2) Second-hand materials.- Second-hand building materials may not be used unless such materials-

a) are sound; and

b) comply with the requirements of these by-laws; and

c) have been thoroughly cleaned and all adhering other materials which would interfere with their intended function removed.

(3) Cement.- Cement used in masonry shall comply with the requirements of C.A.S. No. A46:

Provided that cement not so complying, but, nevertheless, complying with a specification acceptable to the local authority, may be used.

(4) Lime.- Lime used in masonry shall comply with the requirements of C.A.S. No. A15, Building limes.

(5) Fine aggregate(sand).- Fine aggregate used in mortar shall comply with the requirements os C.A.S. No. A34, Aggregates for concrete, and, in addition-

a) at least 97 per centum of any sample measured by mass, shall pass tthrough a 2,36 millimetre sieve; and

b) the percentage which passes a 75-micrometre sieve when tested in accordance with C.A.S. No. A33, Methods for sampling and testing of minerals aggregates, sands and fillers, shall not exceed 7,5 per centum.

(6) Fine aggregate in concrete shall comply with the requirements of C.A.S. No. A34

(7) Water.- Water for use in masonry or concrete walling shall be clean and free from clay and silt and such amounts of oil, acid, alkali or organic or other matter as, in the opinion of the local authority, will seriously impair the strength and durability of the masonry or walling

(8) Coarse aggregate (stone) .- Coarse aggregate for concrete shall comply with the requirements of C.A.S No. A34.

(9) Standard building units .- The building-units listed in this subsection, when used in construction of buildings, shall comply with the requirements of the standard specification application to the unit concerned, and, in addition, shall comply with the other provisions of this Chapter.

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(10) Hollow glass blocks which are 298, 5 millimetres square in elevation, but which in other respects comply with B.S. 1207, shall also be permitted.

(11) Stone for masonry.- Rubble stone shall have a “crushing value” (10 per centum fine test) when tested in accordance with C.A.S No. A33 of not less than 75 kilonewtons.

(12) Soil-cement blocks and bricks.- Soil-cement blocks and bricks, when tested in accordance with C.A.S No. 41, shall comply with the following requirements-

a) the average compressive strength at an age of 28 days shall not be less than 2,8 megapascals;

b) the increase in mass after immersion in water for 24 hours shall not exceed 12 per centum of the dry mass;

c) the linear expansion after immersion in water for 24 hours shall not exceed –

i) 0,05 per centum where, in the opinion of the local authority, cracking of the walls cannot be tolerated;

ii) 0,1 per centum where the blocks or bricks are to be used only in internal walls.