You have more than enough slope for your roof, however you will likely need some sort of membrane.
Minimum Shed Roof Angle. A professional roofing contractor knows the minimum slope recommendations. Before you install a shed roof, first, know these shed roof advantages and disadvantages.
Minimum shed roof angle ~ Anakshed from lh3.googleusercontent.com
The roof covering protects your shed against the elements and keeps it dry inside. Angle cuts on roof rafters set up the entire framing for roof construction, so it is essential that angle cuts be calculated correctly and accurately for all of the rafters. Flat roofs are more susceptible to leaking than pitched roofs.
Roof pitch, or slope, is a description of the angle of the roof that compares the horizontal run and the vertical rise.
Figure 20.7 s common roof pitches and angles. Create a story and a half structure and place automatic dormers. Roof pitch is a term describing how steep or flat your roof slope is. Note that slope also influences your choice of materials.
