E and F. Gutters between roofs and behind parapets, as G, are subject to similar rules to the last-named with regard to falls and the lengths of the sheets of lead between drips M, or drips and rolls L; the widths being regulated by the width of the gutters, which increase in width in their ascent, as explained in the chapter devoted to "Carpentry."
Fig. 471 represents a section of a gutter between two roofs, where the width of gutter precludes the lead being used in one width, as fig. 472.
It should be here pointed out that a gutter should always be 9 inches wide on the flat at its lowest point, increasing in width as it rises.
G and N. Fig. 473 is a section of a gutter behind a parapet wall or chimney, the lead being turned 4 inches up the wall at X, and covered over by a cover-flashing 5 inches wide, wedged with oak or lead wedges into a brick joint or stone groove. It will be noticed that the lead goes 6 inches under the slates; but this should be increased to 9 inches in flat roofs, where snow would lodge, as the flatter the pitch the less height there is between the top of the gutter and the top of the lead, as fig. 474, for the snow to lie in.
Rolls are used across gutters falling both ways to joint the lead and to divide them as a ridge does a pitched roof.
Fig. 475 gives a longitudinal section of a gutter, starting from a pitched roof, downwards through one drip, which may be treated either as figs. 476, 477. or 478.
H. Cesspools axe boxes formed at the bottom of gutters, to collect the water previous to discharging it through a pipe from a hole in the bottom to the head or downpipe. The best way to treat them is as shown by fig. 479, which needs no explanation; except to say that where the angles, sides, and bottom of the box cannot be bossed in one piece they must be soldered - i.e., copper-nailed and covered with solder (a composition of lead and tin) laid on while hot to adhere to and connect the adjoining lead.
N and P, a gutter and an apron. Fig. 480 gives a section through a chimney, showing the gutter at the back, and an apron flashing in the front, both of which should be not less than 6 inches longer than the width of the chimney, at each end, so that they can be laid on one slate, and covered by another to make a water-tight joint, as fig. 481.
The elevation of the side of a chimney, showing a step flashing, is as fig. 482 These step flashings are more ornamental than the plain cover flashing, fig. 483; and they are either cut out in one piece 5 inches wide to work in with the brick joints as fig. 484, or each is put on as a separate step, as fig. 485; their object, and that of other flashings, being to cover the up turns of gutters, as shown by X, on fig. 473; or of soakers, as fig. 482; a soaker being a small piece of lead the length of the gauge and lap of a slate or tile (as explained in the next chapter), by 6 or 7 inches wide, 3 of which go on and under the slates, and the remaining 4 are Rimed up the chimney or the gable, as fig. 486.
Flashings must always lap at the angles round a chimney - i.e., the step or side flashing must turn round the angle, on to and over the apron; and the cover Hashing of the gutter must do the same to the step or side flashings, as shown. Secret gutters are sometimes used, in lieu of soakers, up gables covered with copings, as fig. 487 in section.
A tingle, as fig. 488, is a substitute for wood-rolls, though little used.
A welt, as fig. 489, is a folding of lead used to joint lead, where rolls are not used, and it is especially suitable for vertical lead-work, the under piece being copper-nailed, as shown.
Soldered or lead dots are used for securing lead on vertical or flat surfaces, where neither rolls, tingles, nor welts can be used, the mode of procedure being as follows: a hole is scooped out of the boards, the lead dressed in and screwed down, and the hollow is afterwards filled up and sounded over with solder, as fig- 490.
A raglet is a groove cut in masonry to receive the turn in of lead; and when this is done on the top of blocking course, and over flat surfaces, the lead is "burnt in" - i.e., the "turned in" is secured by running molten lead into the groove or raglet.
A dottle-nosed drop is as fig. 491, from which it will be seen that the upper board projects sufficiently to protect the turn-up of the lower gutter and the top gutter is dressed over so as to form an apron. This mode has the disadvantage of the lead apron being easily turned up, an objection which is obviated by treating the drips as in figs. 476, 477 and 478.