- Author
-
Rossiter, W. J., Jr.
|
Denchfield, R. D.
- Title
- Field Study of the Performance of Polymer-Modified Bitumen Roofing.
- Coporate
- National Institute of Standards and Technology, Gaithersburg, MD
Denchfield Corp., Silver Spring, MD
- Book or Conf
- National Roofing Contractors Association. Problems: Issues and Answers. 10th Conference on Roofing Technology, Proceedings. April 22-23, 1993,
National Roofing Contractors Assoc., Rosemont, IL,
Gaithersburg, MD,
48-58 p.,
1993
- Keywords
-
roofs
|
building technology
|
field study
|
low-sloped roofing
|
membranes
|
performance
|
polymer-modified bitumens
|
standards development
- Abstract
- This report presents the results of a field study of polymer-modified bitumen roofing. Observations on in-service performance are beneficial for identifying field problems that require study to attain solutions. Fifty-three roofs, ranging in age from 24 to 131 months and lacated in Washington, DC/Baltimore, MD, Jacksonville, FL, and Dallas, Texas were inspected. The types of asphale modifiers were almost equally distributed between atactic polypropylene (APP) and styrene-butadiene-styrene (SBS) block copolymer. Re-roofing predominated the type of construction and was divided somewhat evenly between tear-off and re-covering. The overall performance of these relatively young roofs was considered to be satisfactory. About 70 percent of the roofs were considered to be satisfactory. About 70 percent of the roofs were considered visually to be in fine condition. Still, about a quarter of the roofs showed some defects that contributed to a lowered performance ranking. The key defects observed with some membranes were surface cracking of both APP and SBS sheets, loss of granules (particularly in ponded water), slippage of SBS sheets, and disbonded lape or relatively extensive repairing of the laps of an APP system. Although limited, the field experiences provide evidence that performance-related standards are needed to evaluate the membrane materials' ability to resist such defects and to minimize future problems.