FINISHING THE EXTERIOR The exterior of the woodshed was trimmed out in similar detail but in a smaller scale to the garage. We used all PVC trim, pre-primed cedar clapboards and stainless steel nails. We used Western Red Cedar clapboards for this project. Cedar clapboards contain natural oils and resins that protect the wood from insects and rot. Cedar is
known for its durability and ability to withstand weather. (Problems that arise on homes are not usually attributed to the type of siding but to the installation and lack of proper flashing and drainage planes.) Tip: If your siding is not already primed then prime it. Prime all cut ends and edges of the clapboards. The end grain of all wood products absorbs liquids up to 250 times more rapidly than other wood sur- faces. Also, avoid finger-jointed clapboards for a high-quality job. Before installing the siding, properly prepare the home exterior walls: Install building paper or a vapor barrier. Make sure that flashings are installed to prevent moisture from entering wall and roof spaces. Flashings are important in control- ling moisture in wall assemblies. Flashing intercepts and directs the flow of water away from the building to designed drainage paths. Seal doors, windows and other joints with rubber flashing, sill pans and special tapes. Use high-performance acrylic-latex caulk to seal gaps around win- dows, doors, corners and other exterior joints that are exposed to potential water intrusion. Caulking will eventually fail and need maintenance. Caulking can never replace proper flashing. Spacing for the siding should be laid out beforehand. Many builders install at 5-1/2 inches with a 4-in. exposure to the weather. Spacing can be changed or tweaked in order to get the siding to land on top of doors and windows. For fastening, stainless steel nails are the best quality. Use No. 304 stainless for general siding applications and No. 316 for sea- coast exposures. Hand-nailing is better than using a pneumatic nailer because it allows you to determine if you’re nailing into the studs, making it easier to control the depth of the fastener. Install clapboards by face-nail- ing them to the house studs with 1-1/4-in. penetration into solid wood using one ring-shank nail per stud spaced at a maximum of 24 in. on center. Place the nail just above the overlap. Take care not to nail through the overlap of two pieces. Keep nails 1 inch inward from the edges. Clapboards are installed with butt joints. I suggest using tar paper roll tape to flash behind all vertical butt joints. Make sure your tar paper overlaps the clapboard installed below so water or mois- ture can drain out and on top of the lower clapboard. Butt joints between boards should be stag- gered and made on studs. Install siding snugly to other clapboard pieces and trim, and make sure the clapboards are level. Keep the siding a minimum of 6 or more inches off the ground and 3/4 to 2 inches off roofs to prevent moisture from wicking into the end grain. The walls were then sided with pre-primed Western Red Cedar clapboard.