Projecting cornices, belt courses and other trimmings should have sufficient depth that they will balance on the wall, and all projecting stones should have a drip as near the top of the stone as possible, to prevent the water from dripping over the rest of the cornice and down on the wall. Thus in a cornice such as shown in Fig. 91 the stone should be cut at a sharp angle at A, so that some of the water may drop off, and there should be a regular drip at B, that the water may not run down on the wall. It is a.
good idea to cut a drip in all window sills, as shown in Fig. 92. In the summer dust always lodges on a sill or projecting ledge, and when it rains the water washes the dust, which often contains cinders, over the face of the stonework and down on the wall, causing both to become badly streaked and often unsightly.
The architect will find that, if he is careful to provide drips on all mouldings and sills his buildings will remain bright and clean for a much longer time than would otherwise be the case. It is even better to change the profile of the moulding, if necessary, to provide the drip, as the most beautiful moulding looks unsightly when streaked and stained with dirty water.
Washes. - The top of all cornices, Delt courses, capitals, etc., should be cut so as to pitch outward from the wall line, as shown in Fig. 91.
Fig- 93. - Top of Belt Course.
If the top is left level, the rain water falling upon it will, in time, disintegrate the mortar in the joint above and finally penetrate into the wall. Surfaces beveled in this way are called washes.
When the face of a wall is broken with pilasters, or the windows are recessed, the wash on the belt courses should be cut to fit the plan of the wall above, as shown in Fig. 93.