There are several outdoor shed roof designs to consider when building a shed in your backyard. Choosing an outdoor shed roof design often involves considering the region you live in and the function the shed will have. Some designs include the saltbox, gambrel and pent. For instance, Using a gable or gambrel roof on your shed will make it better suited for storage. These designs give you lots of storage space above your head. The gable design of is a two-sided roof with the shape of an A-frame. The gambrel roof is also known as a barn roof and also has two sides. Each side has two sections, each with a slightly different slope. The gambrel roof is more complicated to build then the gable roof, but does give you a little more storage space in the loft.