ENGINEERING WORKS, ETC.
991
The whole of the roof in its length, and to the height of the firstpurlin on each side, is covered with ij^-inch wrought, one sidegrooved, tongued, and chamfered red Riga boarding, securely naileddown to the packings, and a wrought one-sided facia 11 inches by1 inch, with chamfered edges, and scribed between the main andintermediate ribs, is fixed against the brickwork at the bottom ofthe boarding along each side on the inside of the roof.
The last bay on the north side is covered with No. 16 gauge zincof Italian pattern on i^-inch boarding, and all proper fitments,flashings, &c., necessary to make this portion of the work perfectlywater tight. The gutter on each side for the whole length of theroof is laid with 7-lb. lead, turned up 6 inches on properly framedand blocked 1 *^-inch gutter board and bearers; with cess pits, pipes,&c., having 5-lb. lead flashings let into walls and secured withproper wall hooks, and pointed with Portland cement.
The whole of the internal woodwork of the roof is knotted, primed,and stopped, and has three coats of the best oil colours; the externalwoodwork is knotted, primed, and stopped, and both wood and ironhas four coats of the best oil colours.
The whole of the iron work in the roof was properly freed fromrust, and had one coat of gray colour before leaving the con-tractor’s yard, and after completion had two other coats of the bestoil colours. Mineral colours without any admixture of lead or zincwere alone used, on account of the sulphurous fumes from the loco-motive engines.
The following is a detailed list of ironwork in one bay of 20 feet,that being the distance of the principals from centre to centre:—
No.
tons. cwts. qrs.
lbs.
Weight of rib when put together, exclusive of cast iron,...
7
11
9
4
Lattice purlins,
1
8
O
4
8
Trussed do.
1
9
3
20
2
Ventilators at bottom of glass,
0
6
26
8
Z bars 20 ft. long,
0
12
0
24
2
Angle irons, 6 in. x 3 in., for Ventilators,.
0
3
2
26
4
Do. 4 in. x 2 in., do.
0
4
2
16
3
T-iron arches for lantern,.
0
4
0
5
6
T - iron brackets for do.
0
1
0
14
30 ft. super ridge cover, at 4 lbs. per foot,.
0
1
0
8
60
T-iron glazing bars, 8 ft. 6 in. long,
1
4
0
12
120
Do. do. 8 ft. 3 in. long,
2
6
0
8
4
Intermediate rafters, H iron, each 20 ft. 10 in. long,
1
0
2
12
8
Wrought-iron angle-iron brackets, under ends of purlins,
0
0
24
4
Lugs, top of intermediate rafters, ...
0
0
0
16