Hips And Ridges

Like the Siamese twins, it is difficult to separate the one from the other. The hip should be divided into equal parts, but no piece of lead should exceed 10 ft., and is much better about one-third less. The width to go round the roll can easily be taken by a strip of lead, and marked with a chalk-line upon the lead, allowing 6 in. on each side - or whatever width may be specified - for the lay-down upon the slates.

2. The wood-roll should be so fixed that the wings or roof-flashing may key well under it, and for this purpose the bottom of the roll must be kept up about 1/2 in. above the line of the top of the slates. When the roll has been fixed higher than necessary, and the plumber cannot get the carpenter to lower it, he should not attempt to make two horizontal angles, as in forming the one he will destroy the trueness of the other. What he has to do is to see that the lead clips the roll very tightly, and that he secures it there by a proper tacking of the wings.

3. To avoid indentations and tool-marks the lead should be carefully dressed over before it is turned up. Two lines should be struck upon the face of the lead, to show where the wings on both sides of the roll are to be turned up, and a chalk-line should be struck midway between these lines to show the middle part of the roll. The sides or wings should then be turned up at right angles, and the roll angles cut in with the hornbeam dresser and big hammer. At any part of the hip or ridge where there is to be any bossing, at a roll-end or intersection, the angles should not be cut in.

4. In fixing the lead in its place, with the plumber at one end of it and his mate at the other, the turned-up lead (looking like a trough gutter) is lifted up at one end and banged down with a considerable degree of hardness, and then the other end is treated in a similar way. After one or two bangs, the middle chalk-line being kept true with the middle of the roll, the wing on one side of the roll is pressed down with the hands, and then the wing on the other side, and the angles driven in under the roll.

5. Great care should be taken to cut the angles in truly, and this is readily done by keeping the edge of the dresser (the hornbeam dresser) straight, and pressing its side, as a guide, tight against the roll at every stroke of the big hammer or big mallet. If this is done properly there will be no necessity to use the dresser upon the roll, and the hip will look as straight and smooth as a gun-barrel. When the hip is conspicuous from the ground, the underlap should be countersunk into the roll.

6. The top end, or underlap, of each piece of lead should be nailed with about half-a-dozen strong copper nails, or stout iron clout nails; but in most cases the nails to the ridge-lead may be a couple less. The laps to the ridge should be 6 in., but they may be a little less to the hip, though 6 in. laps throughout are best.

7. In bossing down the end of a hip roll, be careful not to split the lead at the top of the roll-end, or in the angles of the roll. If the roll be a large one, 3 in. or larger, take off the arris the keenness of the end of the wood-roll with a pocket-knife, chisel, or rasp, and boss down the lead with a small mallet, beginning a little way out from the end of the roll, in order to work back an extra thickness upon the top of the roll-end, to strengthen that part for the further bossing. Open out the lead at its end with your hands, and work it back towards the roll. In continuing the bossing keep the lead from buckling, using a dummy inside if necessary, and remember that all that is wanted is a disc of lead not equal in area to half the surplus lead at your command.

8. To work down the overcloak at the intersection of the hips with the ridge, be careful to have an extra width of lead round about such points, and see that there are no nail-heads in the underlaps to cut through the lead at the points of the bossing. Lift up the end of the overlapping ridge-piece and bang it down several times, as if you would drive and jerk all the lead into the many corners before you begin the bossing. And then when you begin the bossing, with a small mallet, keep the underside of the lead up from the ridge, as by this means, when the bossing is nearly done, you can work the extra lead which this will give you round to the underside of the roll at the very place it is wanted, to thicken the lead in the corners of the intersections, and to keep it there. This is best done with a box-wood dresser and mallet, the mate pushing up the side or wing all the time with his stick. The lead for working up into the intersections can be drawn from the margins and from the end of the ridge, working it up towards the end of the bossing with the blunt chase-wedge, and finishing it off with the sharp one and box-wood dresser.

9. The sides or wings should be secured in their positions by lead tacks 2 1/2 in. or 3 in. wide, of a strength 1 lb. to the superficial foot stronger than the lead of the hips and ridges, and about 2 ft. 6 in. apart to the former, and 3 ft. 6 in. apart to the latter. The tacks should be nailed by two stout clout nails to the wood hip; and in trimming the edges of the sides they should be notched into them, to give a straight line to the edges, and turned down upon the lead about 3/4 in. Where there is likely to be any traffic, or where there are great winds, the turn-round of the tack would be better welted. (See Tacks, Chap. XIV.)

10. To secure lead hips to Mansard roofs, or to roofs of great pitch, where the lead is nearly vertical, a lead tack, of a sufficient width to clip round the roll and about 6 in. long, should be soldered or burned to the underside of the lead, and the tack turned round upon the wood-roll, and secured on both ends by stout copper screws, three or four to a side. The wood-roll should be countersunk to receive the thickness of the solder and of the tack, which should be of 8 lb. lead, to further add to the support of the lead hip, and to prevent the appearance of any tack on the external face of the roll. The tacks should be not more than about 2 ft. 6 in. apart, to hips of 7 lb. lead.

11. Laps or Passings generally. - Hips and ridges, curb and step-flashings, and narrow apron-flashings, should have a lap of 6 in., though for step-flashings and hips, where the roof has a sharp pitch, a little less suffices. In narrow cover-flashings to the stand-up of flats and gutters, a lap in the flashing of 4 in. is all that is necessary; for the lap of the flashing upon the stand-up of the flat or gutter, 2 1/2 in. or 3 in. will do very well.

The overlap in cover or horizontal flashings to flats and gutters should be cut in a line with the edge of the overlap of the drip. In exposed positions the edge of the overlap should be made to stand northwards or eastwards, and not towards the south-west, for the driving rains to drive between the laps. (See Welts, Chap. XIV., Art. 16.)

12. For lead bays to roofs, where there are no drips, and the sides are too long to cover in single lengths, the lap, when the fall is about 1 ft. in 3 ft., should not be less than about 12 in.; and even with such a lap capillary-attraction is so great that it is better to cut condensation channels in the boarding, and dress the underlap into them, as shown by the dotted lines c C, fig. 23. The contact between the two surfaces will thus be broken, and the capillary attraction retarded. The capillary attraction between the surfaces of the roll-laps can easily be interrupted, if not entirely prevented, by making a hollow ring round the underlap of the roll, about 8 in. or 9 in. up from the edge of the overlap, as shown in fig. 23. In the case of a wood-roll, a hollow, 3/4 in. wide and 1/2 in. deep, can be cut with a gouge, and the underlap dressed down into it; and in the case of a seam-roll, a hollow ring can be formed in the roll with a chase-wedge.

Fig. 23.