Ridges and Hips
The plumber having put up or laid his gutters, flashings, valleys, etc, during the time he has been seeing after his pipes, the slater has not been idle, for he has got the roof all slated, and the plumber may now put on the ridge, indicated in Fig. 46, which may be either of lead, zinc, or iron. The least breadth, generally speaking, of either lead or zinc ridges is one foot, which allows a cover of about 4 in., or fully that, on each side over the slates; but in many cases a greater breadth is used and found necessary, in order to give the slates sufficient cover.
After the lead has been rolled out and beaten into its place with the usual wooden "dresser," Fig. 71, a strong lead-headed slate-nail is driven in at a distance of, say, every two feet or so into each side of the top part of the ridge. Sheet lead for the ridging majr be from, at the lowest, 5 lb. up to 7 lb. or more per square foot. When less than 5 lb., it is often torn up in a high gale of wind, and even although (as is done in some cases where the lead is much exposed to thieves as well as to the wind) galvanised iron ridge straps are put on every three feet or so, yet if the lead be too thin it is sometimes torn up between the straps. These ridge straps are made of hoop iron about lb in. broad and £ in. thick, bent into the form shown by Fig 71a, and with two £-in. holes for the nails to go through as shown.
If, however, the ridge is to be covered with zinc, then zinc ridges are generally put on in 8-ft. lengths, with three straps to each length, or one about every 2± feet. Where the straps are put on at one every 4 ft. it makes a bad job, and does not give the zinc fair play. Each length of ridge is allowed to overlap the other about 2 in. Zinc ridges are made of sheet zinc from Nos. 10 to 14 and upwards. No. 10, which gives about 12i oz. to the square foot, is indeed little enough; for a good job a greater weight must be used. Anything less than No. 10 should not be put on unless for some mere temporary purpose.
In the neighbourhood of chemical works especially it is a good thing to give the zinc a coat of white-lead paint for protection from the acid fumes. Where this has not been done I have seen the zinc on the side of the roof next the chemical work all eaten into holes and wasted, while the
Another plan for fastening on the zinc ridges is to groove out the wood ridge as per Fig. 74, and drive in iron staples in the groove, as shown at X; then, at corresponding distances, galvanised iron, or, perhaps, copper hooks are soldered on inside of the zinc ridges, as per Fig. 74a, which shows longitudinal section; after which the zinc ridge is put on and slid along into its place, the hook going through
To hold the edge of the zinc ridge zinc clips are nailed over the wood ridge and their ends bent up, so as to clasp the edges of the zinc after the zinc ridge is put on. This plan, which was known as Fox's Underlock Fastening, is, so far as ridges are concerned, more troublesome and expensive than the former, described at Fig. 73, with straps, but it appears to have the advantage of doing without holes through the zinc ridge, although many may consider that holes in a good zinc ridge which are filled up by either a copper or a lead-headed iron nail, and protected by the galvanised iron strap, are in practice quite harmless.
Another plan of putting on lead on ridges is that shown by dotted line, Fig. 75, which requires the lead to be about 19 in. or 22 in. broad. When the top part is kept about, or fully, 4 in. broad, the plumbers or sweeps, &c, may then walk right along on the top of the ridge, in place of on each side of it, and so save the slates.
Fig. 76 is section of another style of ridge; to hold on and keep in position the round wooden baton, shouldered iron spikes are used, which are first driven down into the wooden ridge below them, and, holes being bored in the wooden baton, it is put down on the spikes to the shoulder, and the top of the spike projecting through the hole is then bent over so as to hold like a rivet. The lead or zinc is then pub on as per dotted line Fig. 76.
They are cast to suit the pitch or inclination of the roof. They can be had either quite plain, as per Fig. 77, or with many different styles of ornament to suit the character of the building, as per Fig. 78. overlaps the other, and as each length is cast with a raised bead at the one end, and a corresponding raised cover, or overlap at the other end, the bead of the one length is covered by the overlapping socket of the other length, and so the junction of the two lengths is made water-tight.