The proper way

A coatings specialist explains how to correctly apply roof coatings


The use of roof coatings is on the rise as a cost-effective, viable solution for weatherproofing roof systems and helping extend their service lives. Whether an asphalt-based or elastomeric coating is used, it's critical the coating is applied correctly to maximize roof system service life and minimize callbacks.

The most common types of roof coatings are bituminous-based (solvent-based) and polymer-based (water- or solvent-based). When applying a roof coating, be sure to use a product compatible with the substrate on which it will be used. Common substrates include polymer-modified bitumen sheets, single-ply membranes, built-up roof membranes and metal roof panels. Be sure to follow all applicable code requirements. Also, follow appropriate safety measures such as wearing safety glasses, gloves and any other personal protective equipment outlined in the product's material safety data sheet.

To select a roof coating, most manufacturers recommend roofing professionals use ASTM International- or code-compliant products at the proper application rate that meet the requirements of some or all of the following organizations:

  • Miami Metro-Dade County
  • Underwriters Laboratories Inc.
  • FM Global
  • Cool Roof Rating Council
  • Title 24
  • ENERGY STARĀ®