Myth busting

The risks and unverified benefits of field coating asphalt shingles

The North American roofing industry is witnessing increasing popularity of numerous technologies aligned with the sustainability movement. Among these, roof coatings are receiving significant publicity from different groups capable of influencing consumer sentiment, including government policymakers, conservationists and coatings manufacturers.

For example, sustainability advocates identify reflective roof coatings' use as a cost-effective way to reduce building energy consumption in hot climates and control the heat island effect.

Roofing professionals long have recognized the viability and advantages of roof coatings for surfacing bituminous weatherproof roof membranes used as part of low-slope roof systems and possess a great deal of experience with coating applications over roof membranes. This is not the case with field coating steep-slope roof coverings. The fact is the most widely used steep-slope roof covering—asphalt shingles—is not designed to accept or require field-applied surfacings.

Coating products and paints advertised as suitable for application to asphalt shingle roof systems currently are available and marketed primarily to do-it-yourself homeowners. Promotional materials for most of the products position field coating as a cost-effective way to extend asphalt shingle roof system life. Language suggesting leak repair and energy-cost savings resulting from the use of reflective coatings also commonly is used.