Tapered insulation is insulation installed in planned thicknesses to create slope on a low-slope or flat roof. Instead of every board being the same thickness, the layout is designed so water moves toward drains, scuppers, gutters, or roof edges.
Why It Matters
Flat roofs still need a drainage plan. Custom tapered insulation layouts can be planned and ordered to help direct water where it is supposed to go, especially when the roof structure itself does not provide enough slope.
Common Problems
Common issues include poor drainage design, missing crickets or saddles, ponding water, confusing tapered insulation with ordinary flat insulation boards, and installing a membrane over a roof surface that still does not direct water properly.
Building Codes & Industry Standards
Tapered insulation systems should follow the roof membrane manufacturer's requirements, insulation manufacturer guidance, energy code requirements, fire requirements, and the drainage design for the roof. The layout should be planned before installation rather than improvised in the field.
Exterior Echelon Notes
Exterior Echelon reviews tapered insulation as part of the full low-slope roof system. The membrane is important, but the roof also needs a drainage approach that makes sense for the building, existing structure, drain locations, and long-term water management.
