Roof Coatings for Commercial Roof Restoration in Northeast Pennsylvania

Acrylic Roof Coatings

Acrylic coatings were originally developed to provide ultraviolet protection for sprayed urethane foam applications. These coatings are now used on various roof membrane surfaces, including single-ply membranes and metal systems.

Acrylic-based materials provide excellent resistance to radiation and hail damage and have the inherent flexibility required to withstand the dimensional instability of most roof membrane surfaces. Some studies have indicated that properly formulated acrylic coatings can reduce surface temperature by as much as 20 degrees F when exposed to direct sunlight at 85 degrees F.

Acrylic coatings are 100 percent acrylic and can be applied in one or more coats. Most manufacturers provide warranties based on the coverage rates; extended warranties require additional coverage. Acrylic coatings should not be applied in freezing temperatures or when precipitation may occur within a specified period from application. The cure time of these products is highly weather-dependent, and cold weather or high humidity will impede curing. Ideal curing takes place in warm weather with low humidity.

Acrylic coatings are economical, provide excellent reflectivity, and are easy to work with. However, These coatings also lose mil-thickness from weathering, require application in an ambient temperature above 50 degrees F, and cannot withstand ponding water.

Several acrylic coating manufacturers now offer instant-set materials. This reduces the cure time of the acrylic coating to a few minutes, thereby eliminating the possibility of coating run-off if there is precipitation directly after application.

Silicone Coatings

Silicone coatings are manufactured with a high solids dispersion of 100 percent silicone. It is a highly elastic material that provides excellent adhesion to the existing surface.

Silicones provide good weather resistance and rarely become hard or brittle. They’ve gained market share in the commercial roof market in the last decade. The rise in applications is primarily due to the material’s ability to withstand long-term exposure to ponding water, as most other coatings cannot.

These commercial flat-roof coatings also provide excellent ultraviolet protection in extreme temperatures and harsh environments and can resist oxidation. Silicone is available in various colors and provides high reflectivity and emissivity ratings.

Some drawbacks are cost, application requirements, and the fact that only a few materials (besides other silicone products) can be applied directly to the silicone surface. Silicone also holds dirt on the surface and loses reflectivity over time.

Polyurethane Coatings

Polyurethane coatings were initially developed to be applied over sprayed-in-place foam roofs. They are now used as coating applications over various existing roof membranes. Polyurethane coatings have the best ratings for impact resistance and foot traffic.

There are two types of polyurethane roof coatings: aromatic and aliphatic. These materials are typically used in combination as a base coat and a topcoat, respectively. The base coat material is durable but does not offer high UV resistance. The aliphatic coating is used as a top surface because it is UV-stable and stays clean while holding color longer than other coatings.

Fluid-Applied Asphaltic Rubber Membrane Systems

Technological advances and labor shortages have led to the development of fluid-applied materials that can effectively extend the service life of the existing roof system at an economical rate.

An asphaltic rubber membrane system that can be applied in cold-process, fluid-applied applications for life-extension repairs has been developed. The asphaltic rubber material combines the elastic properties of rubber with the waterproof/weatherproof characteristics of highly refined emulsified asphalt. The resulting formulations are proprietary materials that form a fully adhered monolithic, seamless rubber membrane. The resulting membrane can range from 20 mils to 200 mils dry.

Unlike coatings that only provide a film surface or adhesives that require reinforcements for waterproofing capacity, the asphaltic rubber forms a monolithic, seamless membrane that provides instant waterproofing/weatherproofing capabilities. Using these materials with coatings provides a long-term, economical repair system.