ForConstructionPros.com

Your March/April 2007 issue featured a much-needed discussion on the hot topic of "coal tar vs. asphalt" sealcoat products. In your article one contributor is quoted as saying "...no manufacturer can claim an asphalt-based sealer or blended sealer meets any specifications because there are no specifications for asphalt-based or blended products."

I hope you will make your readers aware that about 10 years ago the Asphalt Sealcoat Manufacturers Association (ASMA) developed a generic specification for asphalt-based sealcoating products. This specification includes requirements for materials and additives, mix design tests, surface preparation, application rates, curing, measurement, and payment. The specification is available on the ASMA website (www.sealcoatmfg.org). The California Department of Transportation (Caltrans) also has a specification for asphalt-based sealcoat products as does the "Green Book" Specifications for Public Works Construction.

—
Roger Smith
Pavement Consultant
Loomis, CA