Glass In Roofing 3

1 General.- Where glass is employed as a roofing-material or in vertical glazing or louvres at a height of more than 3,5 metres above the level of the interior floor concerned, the glass shall be of one of the types listed in Table VII, and shall comply with the requirements for that type.

TABLE VII

(2) Notwithstanding the provisions of subsection (1), sheet glass may be used in vertical glazing where the area of any one pane does not exceed 0,25 square metre and is supported on all sides and, where louvres form a part of the vertical glazing, the nominal thickness of sheet glass in the louvres shall be not less than 5,5 millimetres.

(3) Width of flat glass in roofing.-The maximum permissible width of all types of flat glass referred to in Table VII, shall be 600 millimetres, and such glass shall be supported at least along both long edges.

(4) Roof-slopes.- The minimum roof-slope for glass roofing on a uniform pitch shall be 20 degrees, except in the case of glass tiles, which shall have the same slope as laid in section 21 for clay roofing-tiles of the same type.

(5) Glazing-bars.- Glazing-bars shall conform to the requirements of one of the following paragraphs –

a) they shall be constructed in accordance with one of the following subparagraphs, being made of-

(i) a steel section sealed with integrally extruded lead sheath-covering (the mass of lead shall be not less than 10 kilograms per square metre, giving a minimum thickness of 1 millimetre);

(ii) a galvanized-steel bar, the zinc coating of which shall be not less than 600 grams per square metre with a capping of non ferrous metal;

(iii) a composite bar consisting of a timber supporting bar with a non ferrous metal section on top to receive the glass, and with a capping of similar metal;

(iv) a reinforced-concrete bar, with approved capping;

(v) a bar of aluminium alloy, with a capping or weathering-wings of aluminium or lead;

b) they shall be made of, or sheathed with, corrosion-resistant material, to the satisfaction of the local authority.

2 See the requirements of Chapter 11 for restrictions on the use of this type of roofing

3See section 27 for the method of glazing to be used.