Lead Gutters (continued 3)
After the gutter has been put into its site, the " doubling " (or wooden fillet) has to be put on, under the top of the lead on the roof, as at N, Fig. 52; while for the front of the gutter at the " blocking-course " two things have to be done—viz., an " apron " has to be put on, and an overflow-pipe has to be put in ; so that if the gutter were choking-up, the water would run off harmlessly by this overflow-pipe o, Fig. 52, instead of getting over the top edge of the lead gutter, and so damaging the property.
The "blocking-course," we shall say, is 6 in. across the top; the " apron," therefore, having to cover it, and go down each side, overlapping gutter inside as per P, Fig. 52, will be about 10 in. broad, which gives 1 in. over front, 6 in. across top, and 3 in. down inside. Of course there may be many "blocking-courses" broader and deeper than this, which will require the lead to be broader; but what is said above shows the principle or method of putting on the lead.
After the lead has been poured in, got cooled, and been beaten a little on the top with a hammer, the button permanently assumes the shape shown at A, Fig. 55, which gives perpendicular sectional view.
In some cases, when the gutters are very shallow—i.e., when they are laid within a few inches of the top of the blocking-course—there is no apron used, the lead being put on all in one piece over the blocking-course, across the gutter channel and up the roof, as per Fig. 56. Whenever gutters are laid in this manner—which is sometimes done for cheapness—and no overflow-pipe put in, care must be taken that the lead is put up the roof a sufficient distance, so that the water, if the gutter gets choked up and over flows, may run over the front of the blocking-course, and not over the top of the lead next the roof.
In some cases, instead of there being only one pipe, as at Fig. 58, there may be two pipes—viz., one at each end, as per Fig. 59. The drips should be about 3 in. deep, no less, if possible, whatever more. It sometimes happens, especially when the drips are considerably shallower, or less than 3 in., that after the lead has been on some time a quantity of dirt, soot, sand, lime, &c, gets blown up between the two thicknesses of the lead, especially at the corners, and in rainy and blowy weather this dirt, getting wet, acts as a sort of conductor or sponge to suck up the water inside, and so over the top edge of the under lead; when this takes place it keeps the wood underneath the lead continually soaking in water, and tends to rot it.
The style of over-lapping the lead shown at b, Fig. 60, therefore, although no doubt done with the best intentions, yet makes a very bad job. If any improvement is wanted upon the simple overlap shown at s s, Fig. 58, it may be had by turning down the top edge of the under lead as shown at c, Fig. 61, or a " clinch " may be formed as shown at d, Fig. 62. These two latter styles are adopted where the gutters are broad and much exposed to wind and rain.
The joiner in this case must see that the top edge of the first drip is still about or nearly 1£ in. higher than the cornice; while the plumber must see that the. water or rain gets exit at the overflow-pipe fully 1 in. lower than the top edge of the lowest portion of the gutter out of which the overflow-pipe is led. The gutters we are speaking of are laid in lengths of from 10 ft. to 12 ft. long, and if the joiner lays down the wooden sole properly an inclination of about 1J in. in the 12 ft. is quite sufficient. An inclination of only 1 in., with a 3-in. drip, makes a far better job than an inclination of 3 in. and only a 1-in. drip.
The lead which goes up the sides of the lower gutters at the drips should be turned in, or doubled over a little so as to form a small roll (say, J in. in diameter), the turn in of the said roll being kept inside the line of the drip. The sides of the lead of the upper gutter at the drips should be left projecting out before the drip about 3 in. or thereby.
We may here mention that the overflow-pipe, R, Fig. 57, is not a round pipe, but a flat or oval pipe made of lead ; it is about 6 in. wide horizontally, and 1£ in. high. Its length is, of course, according to the thickness of the blocking-course. "When putting it in it must be seen that no rain gets in under it from the outside.
In the case of cottages or houses with projecting roofs, Figs. 63 and 64, many little differences in detail occur, and the plumber must make his lead suit the place. To assist in putting the lead into its site in channel in such gutters as here depicted, and also those at Fig. 42, Chapter V., the plumber often gets a piece of wood made the same shape as the gutter channel, only a little narrower, and about 3 ft. long or so, with which he beats the lead into its seat by striking the wood on the top with his hammer, he standing on the wood at the same time, or else pressing it down with his knee.