Tips for shed roof repair include cleaning the roof before starting repairs, avoiding any depressions that hold water, replacing any damaged materials, and applying patches instead of roofing cement alone. Most shed roof repairs require the use of roofing cement. This tar-like material requires a clean surface for proper adhesion.
Before beginning any repairs, use a broom and sweep the roof to eliminate dirt and debris that are likely to cause the repair efforts to fail. If previous patches fail because of dirt, remove the patching material and clean the area before applying any new roofing.
Shed roofs tend to have very shallow or no slopes; pooling water is one of their greatest enemies, and standing water eventually leaks. Sometimes, the standing water causes deterioration of existing roofing materials, and in other cases, it seeps through the roof. Avoid repairs that create dams that create pools.
While filling the crack with roofing cement and hoping for the best is common, a longer lasting approach is to cut and remove cracked or otherwise damaged materials and replace them with a patch. Roofing cement provides the adhesive for the patch. Lift the edges of the existing material at the edge of the patch, and spread cement evenly under it to create a waterproof barrier.