A properly designed tapered roof insulation system not only provides the necessary r value and the support for the roof system but it helps extend the life of the roof system because it provides.
Flat roof insulation slope layout.
Flat over structural slope backwash detail backwash overlayed on adjacent flat over structural slope when roof drains are located a great distance away from a sloped roof edge more than 48 it can be more cost effective to use a tapered backwash.
To add a slight slope to an entirely flat roof to help shed water install tapered foam board insulation underneath a membrane roof.
Polyiso xps and eps roof.
From there the flat roof system you choose will determine the materials you apply.
A note to consider before construction.
Tapered backwashes can also help reduce the insulation height at the roof edge.
Consider geography budget and use for the roof to determine the best option.
The crickez system helps to simplify roof crickets with quicket.
Some so called experts online may recommend the following claiming to achieve a greater r value at a lower cost.
Good questions regarding water and low slope membrane roofs where slope in the structural roof deck may not be adequate.
If insulation is installed below the flat roof deck this is called a cold roof.
Tapered roof insulation and crickets are designed to provide effective drainage for epdm tpo pvc and built up bur membranes.