At the bottom of all wooden walls and just above the masonry wall there should be an offset or water table to throw the water which runs down the wall away from the mason work. Fig. 156 shows a section of water table that is much used and which answers every purpose. The flashing shown by heavy line is often omitted, as it is not necessary if the siding is tightly fitted on the board b.
Very often, when stone walls are used for the underpinning, the wooden sill is placed 3 or 4 inches in from the face of the wall, thus giving a greater projection to the water table, but the construction is essentially the same.
Corner Boards. - When a wooden wall is covered with siding or clapboards, it is necessary to finish all the angles of the building with boards, put on vertically, for the siding to butt against. These boards are called "corner boards," and when plain are usually from 4 to 5 inches wide on external angles, and 2 or 3 inches wide at internal angles. On "Colonial houses" the corner boards are fre-quently made in the shape of pilasters, from 10 inches to 18 inches wide and 1 ¾ inches thick.
When the walls are shingled corner boards are not needed, and are therefore seldom, if ever, used. Belt Courses. - Wooden belt courses are frequently placed on the walls, or across the gable ends of wooden buildings, and occasionally on brick buildings. They are generally built up of thin stuff, as shown in Figs. 152 and 154a, nailed to forms or furring blocks, which are nailed to the sheathing of a wooden house, or to bond timbers or lookouts on a brick one. They may be constructed in any shape, to suit individual taste, but the top should always pitch outward so that the water will run off freely, and a good drip should be provided at the outer edge. Where the top joins the wall it should be flashed with tin, lead, zinc or copper, about 4 inches wide, and very often the entire top is covered with tin or zinc. On shingled walls the shingles are usually brought out over the belt course, as in Fig. 154a, in which case flashing is not required.
Fig. 156. - Water Table.