Editor's note: The following views are those of the author and not necessarily those of NRCA or Professional Roofing magazine.
Roofing professionals rarely get to walk over a functional roof for the sole purpose of observing how it is doing. We may walk across a roof we helped design and install, but ordinarily, we are there for another reason and do not have time to stop and ponder its performance.
Time goes by all too fast; in fact, we are more than halfway through the first decade of the 2000 millennium. What changes have occurred in roofing technology since 2000? A number of new products now are widely used, such as low-rise adhesive foam and self-adhering membranes. There also is a single-ply membrane that was introduced in the early 1990s—TPO. How is this material doing?
Our time-honored single-ply roof systems—EPDM and PVC—are adapting to the use of adhesive foam. Built-up roof (BUR) systems using asphalt or coal tar have lost popularity in some quarters, but more than a few building owners have nothing but BUR systems and continue planning for new ones. Polymer-modified bitumen systems are now mature; their performance is accepted and acknowledged. Self-adhering modified bitumen systems are catching on. There are few true equals when specifying these products. Metal and spray polyurethane foam- (SPF-) based roof systems also have gained market share; we even see a wider acceptance of residential metal roofs. SPF is in much wider use than 10 years ago; there seems to be a heightened interest for this system among a number of roof system designers.