SPF systems require a coating. The range of products used over SPF includes one- and two-part urethanes, polyureas, silicones, and water-borne acrylics. Installers usually can apply coatings the same day they apply foam to protect the urethane from ultraviolet (UV) rays.
SPF is useful in roof coating and rehabilitation projects, and it bonds to most roofing materials. It also adds extra insulation value by preventing heat from conducting through fasteners to the underlying roof deck. SPF is self-flashing and monolithic, and a skilled applicator can use it to address a host of drainage issues.
Applicators also can use the products cited for use on metal to recoat SPF systems. But manufacturers often require adhesion tests on a roof membrane sample, along with an appropriate primer, to help ensure the new coating properly adheres to the old coating.
Silicone, polyurea and aliphatic urethane coatings resist recoating, so managers can contact the roof-coating manufacturer for specific instructions and guidance. Surface scarification often is effective when applicators use a different coating type for recoating.
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