A gable roof construction features a sloping roof that is angled downward towards the home. This design is great because it is not only easy to build, but it is also easily modified. The slope of the gable roof keeps snow and rain from pooling, so it will withstand extreme weather conditions as well as mildew, mold and rot. A gable roof can be constructed by someone with minimal knowledge of carpentry with access to rudimentary tools and the proper materials.
Step 1 - The Plans
Measure the size of the home to get an accurate idea of the length and width of the proposed gable roof. Consult local building codes to find out height limitations. It is important to be very precise in your measurements. You will need to deliver a set of detailed plans in order to get a permit to build the gable roof.
Step 2 - Rafters
The size of the rafters are determined by the size of your home and the proposed angle of the gable roof. Measure the length from end to the other and make sure you mark off the notches meant to fit onto the walls of the house. It is important that they remain uniform.
Step 3 - Ridge Board
The ridge board sits at the top of the roof horizontally. Mark each of the rafter positions onto the ridge board, and then attach them all to the studs using nails or bolts.
Step 4 - Walkway
To work around the gable roof, you will need a firm walkway. Place the plywood sheet on top of the joists and nail it down. You can now access the roof area easily and safely.
Step 5 - Ridge Board and Rafters
Lay the ridge board on top of the walkway in the direction you need it to face. Do the same thing with the rafters by placing them on the top plate. Place the rafters in the order that they'll stand.
Step 6 - Final Assembly
Place the 2 end rafters in place first by fitting them with the notches and then bracing them. Raise the ridge board until it is between the rafters and affix a stud to the gable at the end which extends downward to the top plate. Use nails and a brace to secure it.
Affix the rafters to the ridge board by beginning at an end then working toward the center. Raise and attach each of the rafters but going from one end to the other end switching sides for each rafter. This keeps the ridge board balanced.
Put plywood on the rafters along with waterproofing materials. This will help to keep the weather out of the gable roof. Attach to the rafters with nails.
Finish by affixing the shingles to the plywood. Use roofing nails for this job.