On existing built-up roofs, loose gravel and dirt are removed by power brooming and vacuuming. If necessary, blisters and saturated areas of the existing roof are removed.  Sandblasting and / or priming are applied to metal surfaces as required. Most roofing surfaces are also primed prior to foaming.

Polyurethane Foam Application

Polyurethane foam is applied with a two component proportioning machine.  This provides mixing of the components in the spray gun.  The foam is applied as a liquid and rises in a matter of seconds.  Within minutes, the surface is firm enough to be walked upon.  The roof is sprayed to the design thickness.. Flashings, penetrations and parapet walls are sprayed to form one monolithic surface.. Depressions due to roof sagging can be built up by spraying to facilitate proper drainage.

Elastomeric Coating

After curing of the foam surface, an elastomeric, weather resistant coating is applied.  To ensure uniform coverage, two or more coats are normally applied.  These coatings are designed to withstand water, ultraviolet radiotion and normal wear for many years of services.  The use of white coating further reduces heat load and thermal stresses in the structure.