How Does a Spray Foam Roof Get Installed?

Spray foam roofing installation is a precise, multi-step process. Here's exactly what happens from start to finish.

Step 1: Inspection and Assessment

A qualified contractor performs a thorough inspection with core samples to assess moisture levels in the existing insulation and determine roof eligibility. An infrared scan may be used on larger roofs.

Step 2: Wet Insulation Removal

Any areas with saturated insulation are cut out and replaced with dry insulation to match the surrounding level. This is non-negotiable for system performance and warranty compliance.

Step 3: Surface Preparation

The existing roof surface is power-washed to remove all dirt, debris, and contaminants. Primer is applied where required by the substrate type and manufacturer specifications.

Step 4: Foam Application

A two-man crew operates plural-component spray equipment. Component A (isocyanate) and Component B (polyol resin) are heated separately and mixed at the spray gun tip, reacting and expanding into rigid closed-cell foam. The foam is applied in multiple lifts to achieve the specified thickness, with depth probes used throughout to verify consistent coverage.

Step 5: Topcoat Application

Within the manufacturer's specified window after foam application, the protective topcoat — typically silicone — is spray-applied at the required mil thickness for the chosen warranty. Granules are broadcast into wet coating at designated foot traffic areas.

Step 6: Inspection and Warranty

A manufacturer representative or third-party inspector verifies thickness, coverage, and quality. The manufacturer then issues the warranty documentation.