The Cost Effectiveness of Alpha SPF Roofs: Casa View Elementary School Roofing Case Study

Authors: Dean T. Kashiwagi (PhD), Dhaval Gajjar (PhD) and Charles J. Zulanas IV (M.S)


The performance of the Alpha Sprayed Polyurethane Foam (SPF) roofing system is perceived as not an economical option when compared to a 20-year modified roofing system. The Dallas Independent School District (DISD) is replacing the existing Alpha SPF roof systems with new roof systems rather than recoating the existing systems at a cost that is 100% more than the recoating costs. The DISD is in a heavy hail area, and the proven hail resistance of the Alpha SPF roof system is an additional benefit for DISD who is self-insured. The Casa View Elementary School roof system was installed with a Neogard Permathane roof system in 1987. This roof was hail tested with ten drops from 17 feet 9 inches of 1-3/4-inch steel ball (9 out of 10 passed) and three drops from 17 feet 9 inches with a 3-inch diameter steel ball (1 out of 3 passed). The analysis of the passing and failing core samples show that the thickness of the top and base Alpha SPF coating is one of the major differences in a roof passing or failing the FM-SH hail test. The current potential cost savings of purchasing a 61,000 square feet Alpha SPF roof versus modified bitumen roof is approximately $610,000 for DISD. The past hail tests on Alpha SPF roof systems show high customer satisfaction (9.8 out of 10) and an over 40-year service life after a $6.00/SF recoat.

Keywords: Alpha roof system, sprayed polyurethane foam, roofing, sustainability, FM-SH hail testing.