- Author
- Rossiter, W. J., Jr. | Seiler, J. F., Jr. | Spencer, W. P. | Lechner, J. A. | Stutzman, P. E.
- Title
- Characteristics of Adhesive-Bonded Seams Sampled From EPDM Roof Membranes.
- Coporate
- National Institute of Standards and Technology, Gaithersburg, MD
- Book or Conf
- U.S. National Roofing Contractors Association. Symposium on Roofing Technology, 3rd International. April 17-19, 1991, Montreal, Canada, 167-179 p., 1991
- Keywords
- roofs | membranes | adhesives | seams | peel strength | microscopy
- Abstract
- This study reports on the characterization of seam samples cut from EPDM roof systems. Data on seam characteristics and failure analysis are needed to further the understanding of seam performance and to develop performance criteria for seams. Forty-eight samples were cut from EPDM roofs whose seams were generally rated as having provided satisfactory or unsatisfactory performance. The samples were subjected to laboratory tests which included identification of the adhesive, measurement of adhesive thickness, and determination of the strength and mode of failure in peel. Comparisons were made between the test results and performance ratings. It was found that the majority of the unsatisfactorily performing seams had been bonded with neoprene-based adhesives and had been exposed on roofs for 45 months or more when sampled. The limited number of samples with butyl-based adhesives were rated as providing satisfactory performance (or not rated). The butyl-based seams were relatively young, and had peel strengths only slightly grater than those of the satisfactorily performing neoprene-based samples. No relation between performance and either peel strength or adhesive thickness was found. The majority of the samples contained relatively thin adhesive layers (less than 0.005 in. or 0.13 mm). Of the samples subjected to SEM analysis, the majority showed evidence of release agent on the rubber and adhesive surfaces analyzed. This finding provided evidence that a field method to judge rubber surface cleannes before application of the adhesive is needed.