Covered Flats or Platforms
We shall now describe the method of using lead and zinc in covering flats, or " platforms," as they are sometimes called, on the roofs of houses, and shall, for illustration. take a flat 16 ft. long and 12 ft. broad, of which Fig. 83 shows section, and which is to be covered with lead. In this case the water runs off at each side of the flat, the rise in the centre being about two or three inches.
Several things have to be attended to here. A flashing about 1 ft. broad, say of sheet-lead, 6 lb. per square foot, has to be put on all around the front of the flat, which flashing can be cut in four pieces, two at about 17 ft. long for the front of the sides, and two at about 13 ft. long for the front of the ends. Four long strips of lead about 4 in. broad are also required to go along front of flat for clinch, two at 16 ft. and two at 12 ft. long. Then the lead for top of flat has to be cut out, say, of 7 lb. sheet-lead, the breadth of the several pieces depending, of course, upon the number of rolls it is intended to have in the length of flat.
Before cutting out the lead the size of the rolls must'be settled, as some allow 3 in. and 4 in. for the roll, and others 2£ in. and 3£ in. I shall, in this case, take the latter, which causes the breadth of each of these eight pieces to be 2 ft. + 2£ in. + 3J in. = 2 ft. 6 in.; and the length 12 ft. + 4 in. + 2 in. = 12 ft 6 in. (or, to allow sufficient for the overlap over the front, better say, 12 ft. 7 in.). The extra 6 in. in the latter is for the overlap and turn-in, or " clinch," at each end.
The first thing to be done, in putting on the above lead cut out, is to nail on the long narrow 4-in. lead strips all round the edge of the flat with lj in. flat-headed nails, other 9 in. lies down on the roof, each other at the four corners of the flat and the narrow strip of lead, or " clinch," at its back, are held by nails driven in as at y, Fig. 84.
After the flashings have been all properly fixed and dressed, the upstanding lead at z, Fig. 84, is then turned down level with the top of the flat as per z, Fig. 85, and its outer edge planed straight. The situation of the rolls isthen marked off as per Fig. 86, which shows longitudinal section of flat.
In cutting out the lead do not scrimp it, more especially as any cuttings are not lost, but melt up again. While I have taken the distance between the rolls at 2 ft., some may make it 2 ft. 6 in., but the former ia best for lead, and in some cases the distance maybe 1 ft.
9 in. or 1 ft. 6 in. leaving the top of the lead to project up 2 in. as per z, Fig. 84. Then, in front of this, put on 'the lead flashing—cut out at 1 ft. broad—as per dotted line, Kg. 84. Its top edge being nearly on a level with the top of the flat, about 3 in. is taken up by the perpendicular upstand, while the
These flashings overlap Both the flashing the same time; and, in addition, both ends of the seven rolls have to be bent down about 2 in. over the edge of the flat. In bending or working these rolls down over the edge of the flat, as per M, N, Fig 91, some can do so without stuffing them; others, again, prefer to stuff the ends of the rolls before beginning to turn them.
This stuffing is done by taking a piece of sheet-lead, about 9 in. long, and rolling it up firmly to the thickness of one's little finger or so, and then slipping this into the roll: the roll is turned down with stuffing in it. When being turned down a small portion of the end of the roll which is too long is cut off.
While working these rolls one of the wooden dressers, cut out to the shape and size of the rolls, as per 0, Fig. 92, is generally used. In order to tie down these lead rolls along their length, lead latchets or " clips " are put inside the roll. These latchets are simply pieces of sheet-lead, about 5 in. long, and 3 in. or 4 in. broad, which are fixed on to the top of the flat, as per Fig. 93, with screw-nails; 2 in. on the flat, and 3 in. of upstand; they are put on every 4 ft. or so, the upstand going inside the seam, as between A and B, Fig. 86 ; and as B on that side only stands up 2i in., while the latchet is 3 in. high, the top of the latchet is bent down over B, and in order to leave no mark in the seam, the thickness of latchet lead is cut out of b's 2£ in. upstand; and, of course, as the lead is being turned over to form roll, Fig. 88, the latchet is turned with it, and perforce takes the same shape, being inside it. The 2 in. of latchet, which is fixed to the wood of the flat, is sunk down in the wood the depth of its own thickness—viz., about one-twelfth of an inch.
In this style of covering tiata with lead no wooden batons are required at all, while the lead is left quite free to expand and contract. In turning over the rolls they should always he turned towards the side which is lca:*t exposed to the wind and rain. In beginning to lay the lead on the top of the flat —although in Fig. 86 I have, for the janpose of illustration, begun in the centre with A and B— the plum her may begin at the side—viz+, at K, Fig, 86, and in turning the rolls he must he careful to keep them all straight and even. Fig. 04 is sketch of the Hat when finished and covered with lead, as above described.
At L, Fig. 90, we see the manner in which a flat covered with lead has the lead bent over the edge of the flat. There is another way in which it is sometimes done, although I cannot express entire approval of it, especially where it breaks in upon the line of the ridge by projecting beyond it. This style, in contrast to.Figs. 84 and 85, is done by fixing on a wooden roll to the front edge of the flat, as per Fig. 96, A being the wooden roll, the dotted line B being the lead flashing put on before A, and the dotted line c being the lead of flat, which is bent around the wooden roll as shown. The lead rolls in this case, while formed as per Fig. 88, instead of being bent over as per M n, Fig. 91, are, of course, bent around the wooden roll as per d, Fig. 97. The size of this wooden roll A, Fig. 96, is about 2J in. or 2i in. deep, and it projects out about 2 in.