Stair-Building and the Steel Square / A Manual of Practical Instruction in the Art of Stair-Building and Hand-Railing, and the Manifold Uses of the Steel Square

by Fred. T. Hodgson; Morris Williams

In the intersection of this roof with the main roof, there are shown to be two valleys of different lengths. The long one extends from the plate at n ([Fig. 14]) to the ridge of the main roof at m; it has therefore a run of 13 feet 6 inches. For the length, proceed as for the hips, by taking 17 on blade of the square and 9 on tongue, and stepping 13 times for the length of the 13 feet; and for the fractional 6 inches, proceed precisely as shown in [Fig. 17] for the hip, by squaring out from the tongue of square No. 1, 8½ inches; this, in addition to the length obtained for the 13 feet, will give the full length of the long valley n m.

The length of the short valley a c, as shown, extends over the run of 10 feet 4 inches, and butts against the side of the long valley at c. By taking 17 on blade and 9 on tongue, and stepping along the rafter timber 10 times, the length for the 10 feet is found; and for the 4 inches, measure 5⅝ inches square from the tongue of square No. 1, in the manner shown in [Fig. 17], where the 8½ inches is shown added for the 6 inches additional run of the main roof for the hips.

Fig. 24. Steel Square Applied to Finding Bevel
for Fitting Top of Hip or Valley to Ridge.

The length 5⅝ is found as shown in [Fig. 20], by measuring 4 inches from a to m along the run of common rafter for one foot. Upon m erect a line to cut the seat of the valley at c; from c to a will be the run of the valley to correspond with 4 inches run of the common rafter, and it will measure 5⅝ inches.

How to Treat the Heel Cut of Hips and Valleys.

Having found the lengths of the hips and valleys to correspond to the common rafters, it will be necessary to find also the thickness of each above the plate to correspond to the thickness the common rafter will be above the plate.

In [Fig. 21] is shown a corner of a square building, showing the plates and the plan lines of a hip. The length of the hip, as already found, will cover the span from the ridge to the corner 2; but the sides of the hip intersect the plates at 3 and 3 respectively; therefore the distance from 2 to 1, as shown in this diagram, is measured backwards from a to 1 in the manner shown in [Fig. 17]; then a plumb line is drawn through 1 to m, parallel to the plumb cut a-17. From m to o on this line, measure the same thickness as that of the common rafter; and through o draw the heel cut to a as shown.