Shiplap siding is an interlocking wooden building material that protects the underlying structure of a house. Shiplap siding is designed so that the lower edge of a board lies over the upper edge of the board beneath it, thereby creating a cohesive shell over the exterior of the house. Shiplap is applied by starting at the bottom of the house and working up.
Use your level to determine the lowest point of the house. Manufacturers recommend the siding begin a certain distance up from the lowest point. Follow these instructions and use your chalk line to snap a guideline where the first course of shiplap siding will be fastened.
Fasten the first course of siding to the wall. Follow the chalk guideline. Shiplap siding should face nailed to furring strips applied over sheathing, or directly to the frame studs, at a distance of no greater than 60 cm (24 inches) apart on centre. Drive nails an inch above the lower edge, and an inch below the top edge of each board. Be careful not to overdrive nails. Siding should be secured, but overdriving the nails can cause warping and inhibit the siding from breathing properly in changing weather conditions.
Use your circular saw to cut the boards to the proper length. Joints between adjacent boards should be fastened to studs, and joints between siding courses should be staggered.
Work your way up the house. Each shiplap board should rest on the top edge of the board beneath it, with the grooved edges of the boards overlapping one another. Check your level every fourth or fifth siding course. If you find that you are losing your level, correct by making minor adjustments over the span of several courses; instead of making a single, noticeable correction.
Inside and outside corner boards can be mitred, or corner pieces can be installed on the house before the shiplap siding is applied. Mitred corners look neat, but can deteriorate more quickly than a prefabricated corner piece. Corner pieces can be installed and then the siding boards are butted up against them.
Siding should be protected with a paint or a stain. Many manufacturers recommend finishing the boards on all side before they are installed on the house.