We are building a 16 x 14ft extension shed off the gable end of our garage. Trying to get a contractor to do this relatively small job has been nearly impossible so we are attempting it ourselves. My question is about the roof. For a simple shed roof other than rafters and joists is there any other bracing required ? We are in Maine where the weight of snow can be considerable. Since it is a simple sloping roof I assume that collar ties are not necessary. Is this correct? Is there somewhere I could obtain plans for an extension shed such as this ?