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