Materials / Spray Polyurethane Foam (SPF) Roof
Spray Polyurethane Foam (SPF) Roof
fluid-appliedA seamless, fully adhered low-slope roof system created by spray-applying polyurethane foam directly to the deck, then protecting it with an elastomeric topcoat (acrylic, butyl, silicone, polyurethane, or polyurea). The foam provides insulation and slope-to-drain in the same application; the topcoat is the wearing surface and is re-applied every 10 to 20 years to renew the system. SPF assemblies are evaluated for hail under FM 4470 (moderate-hail and severe-hail ratings).
Category family
fluid-applied
Typical lifespan
20–40 years
Typical wind resistance
Fully adhered with no mechanical fasteners; IBHS-cited testing on structural concrete decks shows tensile adhesive failures at approximately 900 psf
Cost band
$$$
Slope suitability
low
Typical warranty
10–20 years
Pros
- seamless and fully adhered, with no fasteners or seams to fail
- adds insulation and slope-to-drain in the same application
- hail and wind-driven debris damage typically does not cause the roof system to leak (IBHS)
- minor surface damage is field-repairable with caulk
- renewable system; recoating restores the wearing surface
Cons
- topcoat is the wearing surface and must be re-applied every 10 to 20 years
- fire performance is assembly- and topcoat-dependent (assemblies rated Class A, B, or C under ASTM E108 / UL 790)
- spray application is weather-sensitive and installer-dependent
- low-slope use only
Sources
- ibhs.org verified 2026-07-17