Tongue and groove siding can be installed horizontally or vertically. In horizontal application, start at the bottom and work up with the grove edges facing downwards to assure a weather-tight wall. Siding up to 6 in. wide can be blind nailed with one siding nail per bearing toe-nailed through the base of each tongue. Wider siding should be face nailed using two nails per bearing. Ring shank nails must penetrate 1-1/4 in. into solid wood (see Figure 5).

In vertical application, start at one corner with grooved edge toward the adjacent wall. Use a level or plumbline to ensure that the first board is installed vertically. The grooved edge of the first board may have to be trimmed to ensure a flush fit. Siding is nailed to horizontal blocking lines installed between studs or to furring strips (see Wall Construction). As with horizontal installation, pieces up to 6 in. can be blind nailed and wider pieces should be face nailed.