Whether you develop your own plans or use another's, roofing a shed should correspond with your objectives for constructing the shed overall. Focus on building a roof that is watertight and can protect the contents of the shed, while blending the shed's roof with the roof installed on your home. Erect a shed roof that is economical, durable and low-maintenance.
Build the basic roof structure mainly out of ridge boards and rafters or use roof trusses. These components support the weight of the roof decking, covering and insulation. Mount the ridge board down the centre of the structure for gable, hip and gambrel roofs. Attach the rafters to the ridge board and slope them down to the wall where they are secured. Trusses are triangular-shaped roof supports that can be used in place of the rafters and ridge board. Build trusses yourself or purchase them pre-assembled.
Design the roof so that it is strong enough to support the roof covering, sheathing and accumulation of snow if applicable. Install roof sheathing that is at least ½-inch thick. Cover a pent roof with a single-ply waterproof membrane. For shed roofs designed in the gable, hip or gambrel styles, install shingles, or a covering that matches the home.
Construct a pent roof by mounting beams, which span the structure from the front to the back. Slope the beams about 1/8-inch per foot to ensure proper water drainage. Use OSB (oriented strand board) or plywood for the sheathing. Apply felt, shingles, single-ply membrane or match the roof covering installed on the house.
Build a gable roof in two equal-sized sections. Mount a horizontal board, called a ridge board, end-to-end along the peak of the shed. The ridge board helps to line up the common rafters. Connect the rafters to the ridge board, aligning them with the wall studs. Slope the rafters down to the top plates of the exterior side walls and secure them.
Construct a hip roof with four sections that slope down. This construction method requires the installation of a ridge board. Unlike the gable roof, the ridge board does not extend the entire length of the structure. You need three types of rafters to install a hip roof: common, hip and jack rafters. Follow the plans for the correct placement of the common rafters. Installing the common rafters first will help you line up the rest of the structure. Install the four hip rafters and then the jack rafters. Practice making the required angle cuts for the rafters on scrap wood.
A gambrel shed roof has a barn-like appearance. The roof slopes in two directions. Begin the basic construction method the same as for hip roofs, but make the roof steeper part way between the edge lines of the roof and the ridge board. Make the trusses from sections of roof joists, which connect together with plywood gusset plates. Install the trusses over the wall studs. Consider buying prefabricated trusses to eliminate building them.