It is very common to install pipes or other penetrations for supports through the roof surface. Typically, these supports are flashed in with a rectangular box that is referred to as a pitch pan. This type of detail is common with all membrane systems and installation is similar with all of them.
The pitch pan can be fabricated from metal or plastic. Most single-ply (thermoplastic) manufacturers have pre-molded pitch pans. The diameter of the pitch pan is based on the size of the pipe that it is applied around; there should be a minimum of 2 inches of clearance between the pan and the pipe. The pitch pan corners should have a 2-inch radius and are lapped a minimum of ½ inch. There should be a minimum 4-inch flange at the perimeter of the pan that serves as a base over the membrane surface.