How to build a house

by Eugène-Emmanuel Viollet-le-Duc

The gutters, the discharge of the rain-water, and the roofing now required attention.

“Country builders generally manage roofing but indifferently,” said Eugène, “and especially the plumber’s work. We shall therefore have to be specially careful about this important part of our undertaking; for a house badly roofed is in the same condition as a man incompletely or badly clothed. Both contract incurable maladies. We have no good roof-plumbers here, and must make up our minds to send for some from Paris. That will cost us a little more; but it will be a saving in the end, for we shall avoid incessant repairs and irreparable bungling. As for the slating, we will fasten it with hooks.

“Slates are commonly fastened on deal battens, by means of nails; but to drive these nails into the laths the slate must have two holes made in it, since each is secured by two nails. With the force of the wind the slates shake about, make the holes larger, and ultimately slip off the head of the nails; then they fall. To replace a single slate several must be removed, and the last must necessarily be pierced below the overlap, that is, in the uncovered part of the slate. With hooks we avoid these disadvantages, and anyone can repair the roof. These hooks are made of copper, which allows them to be opened and closed many times without breaking them. Moreover, the slate, being held down at its bottom end, cannot rattle with the wind, and nothing can displace it. In the ordinary mode of (French) slating there are—one over the other—three thicknesses of slate. The exposed part being 4½ inches—the slate is then 13½ inches long. The laths are nailed on the rafters 4½ inches apart from centre to centre (Fig. [60]). Thus at A you see the position of the laths and that of each slate. The hooks lie upon the under slate, in the interval between the intermediate slates, and clip the lower end of the outer slate. At B I show you, in section half full size, the lath, C, nailed upon the rafters, and the hook, whose point is driven into the lath, with its return, E, clipping the exposed end of the slate. So much for the plain parts of the roof; and now for the returns—the hips and valleys. Where these occur, as the slates are not flexible, we must make use of lead or zinc; the first of these metals is much the best, and is less liable to crack and to oxidize. We shall cover the hips with short lengths of lead bent to the form, nailed, and worked in with the courses of slate. In the valleys we shall lay a sheet of lead, on which at either side the slates will lie.

“But you will study the manifold details of roofing when the men are at work, for labour of this kind requires minute care. We have to struggle with a subtle foe—water. It discovers every interstice, and takes advantage of the least negligence to make its inroads; and so much the more since, driven by the wind, it acquires a power and an activity which it would not possess if it fell vertically, like properly-behaved rain. So in climates where showers are gentle and fall only in calm weather, the roofs are simple, and do not require the innumerable precautions demanded among ourselves; and that is why I adopt the plan of securing the slates with hooks. Here the westerly and north-westerly winds are violent, and drive the rain and snow under an angle of 30°. Slates held only at the top do not lie close, and tilt up at their outer extremities, and the rain and snow soon get in. That is also the reason why we have given our roofs an angle of 60°; for the rain, when violently driven, generally descends perpendicularly to this inclination, and there is then no danger of its getting under the outer extremity of the slates.

Fig. 60.

“The arrangement of the gutters also requires great attention. Their channel should have a sufficient inclination—say an inch in a yard—to ensure thorough clearance; but each length of lead or zinc forming the channel should have a drip—a slight step of 1½ to 2 inches—that the water may not find its way under the joints. These requirements necessitate our giving to the gutters a sufficient depth to get these falls from the culminating points to the discharges, or down-pipes, and that these pipes may not be too far from each other, so that the water may not have too long a course to make. Besides this, we should contrive on the front of the gutters, issues, or small spouts for overflows, so that if the snow or ice should encumber the orifices of the down-pipes the water may run off. It is, moreover, desirable to give the back of the gutter a greater height than the front, that the water may in no case get inside. This, then (Fig. [61]), is the section we shall give to our gutters. The stone course, A, behind the gutter being 16 inches high, the board which forms the front of the gutter shall be 13 inches. You remember that upon the cornice-table we left a slope forming a hollow between each joint, to ventilate the bottom of the gutter and to ensure the escape of the water in the event of an overflow. Our gutter, then, will consist of an oak board, B, forming the bottom, of a side, C, forming the front, and of a roll or bead fastened on the top edge of the front. This front board is to be slightly inclined, that the lead lining may have less tendency to give down.

“The eaves of the roof being at D, our lead lining shall be fastened at E by nailing, follow the section of the gutter, and be doubled over at its edge, G. We shall cover the front with another sheet of lead, also doubled over at its top and bottom edges, H I, with clips of zinc screwed to the board. This lead covering of the front will be held by screws, whose heads must be covered with little caps, a, soldered over; then a roll, K, will cover the bead and fold under the doubled edges, G and H.

Fig. 61.—Details of the Plumber’s Work.