Analyzing self-adhering underlayments

Differences between products and product performances cause concerns

Self-adhering polymer-modified bituminous sheet underlayments enjoy widespread acceptance and use in the U.S. roofing industry. According to The 2005-06 NRCA Steep-slope Roofing Materials Guide, nine manufacturers produce 21 self-adhering polymer-modified bituminous sheet underlayment products.

NRCA and many roofing professionals recognize there are considerable differences among some self-adhering polymer-modified bituminous sheet underlayments. To better understand these differences, NRCA performed a limited analysis—including laboratory testing—of self-adhering polymer-modified bituminous sheet underlayments. The results of the analysis may surprise you.

Product usage

Self-adhering polymer-modified bituminous sheet underlayments offer considerable advantages over alternative means of providing waterproof membrane underlayments for steep-slope roof systems. For example, before the development and widespread acceptance of underlayments, underlayments for ice damming areas on steep-slope roof systems typically consisted of applying two layers of organic felt in solid troweled applications of roof cement. The use of self-adhering polymer-modified bituminous sheet underlayments for this application provides a substantially cleaner application in a single labor-saving application.

Log in or register for FREE access to this article and other Professional Roofing online content.

Not a professionalroofing.net user?

Register now for free access
  • Full access to every article
  • Online Web exclusive information
  • Photo gallery
  • Breaking news
  • Online classified ads

Already a professionalroofing.net user?

User name:

Password:

 


Forgot Your Password?