Corner Treatment for Siding

There are several methods used for siding at corners (Figure 112). For siding applied horizontally, mitred corners and metal corners or corner boards are common.

Mitred corners must fit tightly and smoothly for the full depth of the mitre. To maintain a tight fit at the mitre, purchase dry siding and protect it from rain during storage. The siding can be set in putty or sealant to obtain a tight joint. At interior corners, siding is usually butted against a corner strip of 25 or 38 mm (1 or 11⁄2 in. nominal) material, depending on the thickness of the siding. Where rainscreen construction is used, the furring strips should be kept back from the joints where water is most likely to enter, so that drainage and drying can occur.

Figure 112

Metal corners that match the colour of the siding can be used and require less skill than mitred corners or fitting siding to a corner board.

Corner boards are made of 25 or 38 mm (1 or 11⁄2 in. nominal) material, depending on the thickness of the siding. The corner boards are applied against the sheathing with the siding fitted tightly against the narrow edge of the corner boards. Bed the siding in putty or sealant to obtain a tight joint.

Plywood and hardboard are usually lapped at the corners or fitted to a corner board. Lumber siding applied vertically is lapped at the corners.

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