The Viaduct Works' Handbook

60 For slated roofs of the kind shown in sketch, with flat har, ties, and truss rods, wrought-iron struts and rafters :— Approximate price. £ 8. d. Ironwork for roofs up to 40 feet span, including gutters, but without laths, per square ........................................4 19 3 Extra cost, per square,...............................for roofs between.............................40.........................feet.....................and 50 feet span .........................................................,........................................................,........................................................ 0 13 3 Extra cost, per square,...............................for roofs between.............................50.........................feet.....................and 60 feet span .............................................................................................................1 6 2 Extra cost, per square, for laths of iron .................................................................................. 1 14 0 ».....................................................................»....................................................slates (doubling).........................................................................................................................................................................................................1...............................................3.............................................6 Extra cost, per square, for boarding under slates 11 inches thick, grooved and tongued .....................................................................................,................................................................................. 1 6 8 Extra cost, per square, on the part (if any is made) with Louvre ventilators, and without laths, of the pro- portions shown..................................................................................................................................................................................................................................................................................................................................................................................., 6 5 10 Extra on the last item if ventilator be glazed .............................................. 5 8 10 For corrugated iron roofs :— Ironwork for roofs up to 40 feet span, including covering of painted corrugated iron, 16, B. W.G., per square . 7 6 0 Extra cost, per square, between 40 feet and 50 feet span . 0 12 3 Extra cost, per square, between 50 feet and 60 feet span . 0 18 3 Extra cost, per square, on the part (if any is made) with Louvre ventilators of the proportions shown . . 6 5 10 Extra cost, per square, on the part if the ventilator be covered with skylights of glass 910 If the covering is of galvanized iron instead of painted iron it adds about (per square) 0 17 6 Price of corrugated iron roofs in the arched form without any framework, except tie-rods and suspension rods for counteracting the strain on walls — Painted Iron per square. £ s. d. Of No. 20 gauge iron for spans not exceeding 35 feet 2 0 6 „18 „„„„ 210 0 „ 16 „ » „ ,, 3 2 6 Galvanized Iron per square. £ s. d. 296 319 3 18 0 From the above table approximate estimates of most of the ordinary kinds of iron roofing can be formed; but these prices are always affected by the market price of material and labour, and the place of delivery, quantity, mode of payment, &c. The cost of " hipping” a roof, that is, sloping it down at the ends as at the sides, is considerable, notwithstanding that it may appear in theory to require but little, if any, additional material, the external surface remaining the same as though it were finished