Results of Field Investigations: Of the 54 systems tested, only 11 were rated Very Good (9) or Excellent (10) at all three sites. There were 2 Silicone systems, 5 Acrylics, 3 Urethanes and 1 Urethane-Silicone. (Tables 12,13) Of those we have extracted the following for comparison: (Note: All three of these systems were set out at the same time in December of 1978. The results recorded here were observed in January of 1986. total exposure time was 7 yr. 11 months at that time.)
Silicones: Moisture-Cured- System 2G: Dow Corning #3-5000 construction Coating, Gray Base and White Top Coat with Granules over CPR Upjohn 485-2 foam was rated Excellent (10, 10, 10) at all three sites. (Note: the other two Dow Silicone systems (2, 2A) in the study without granules were downgraded due to cracking, checking, bird pecking.)
Acrylics: System 6G: United Coatings "Diathon" with granules over CPR Upjohn 485-2 foam. At all three sites was rated Excellent (10-,10,10), At the seashore site, minor blistering caused slight downgrade. The other two Diathon systems (6,6A) without granules were both rated lower due to pinholing, checking, cracking and bird pecking.
SYSTEM 24G:SWD URETHANE COMPANY'S "1929F" WITH GRANULES OVER SWD 525-2.5 FOAM. RATED EXCELLENT (10,10,10) AT ALL THREE SITES. THERE WAS NO DETERIORATION.
In 1974, dissatisfied with performance of traditional tar and gravel built-up roofing (BUR) systems, the Physical Plant Department began looking for viable roofing alternatives. The BUR roofs were constantly leaking, and because of the nature of BUR, leak detection was virtually impossible.
As the Physical Plant Department began soliciting information from various roofing sources and checking references, sprayed polyurethane foam (SPF) roofs exhibited advantages that seemed to fit the criteria of the University. The Physical Plant Department found the following:
In 1974-75, convinced the proceeding advantages warranted taking a look at this relatively new roofing system, the Physical Plant Department issued contracts for the reroofing of several buildings. One of the earliest roofs done with this system was Davis-Gary dorm. After seventeen years this roof has not leaked and requires minimal maintenance.
Between 1975 and 1977 the Physical Plant Department and TAMU Systems Facilities Planning and Construction (FPC) communicated back and forth concerning the monitoring of these roof installations. New BUR roofs were providing the University with service life of less than five years, and many of the BURs were leaking from the onset. In 1977 the Physical Plant Department foamed over a BUR application that was less than four years old. After monitoring the SPF installations, FPC was also convinced and since 1977, all new roof applications have used SPF roofs.
FPC received numerous complaints stemming from this decision. Few roofing contractors had the financial ability to mobilize spraying foam. Fewer still had the caliber of crews that chemically formulate foam in the field. Though this eliminated potential bidders, it in effect greatly elevated the caliber of roofing contractor performing work at Texas A&M.
Many outside architects working at the University were unfamiliar with the system, and some of these had a reluctance to learn anything new, but the Physical Plant and FPC were adamant. As time went by, architects and general contractors learned the many advantages of the system. This caused proliferation of the SPF Roof systems in surrounding school districts and Universities.
Today over 7 million square feet of SPF roofing has been applied throughout the A&M system. With very few exceptions, these roofs are holding up extremely well. In fact, it is extremely rare that one of these roofs leaks at all. Blister defects, which occasionally occur, do not create leak problems. Most leak problems at our campus occur on the few buildings that still have BUR on them.
In 1985 the Physical Plant Department found another advantage in using SPF roofing systems. For a number of years, Mr. Gerald Scott, P.E. was in charge of roofing and energy conservation within the Physical Plant Department. Vendors of the SPF system always championed the energy saving characteristics of the system. We realized polyurethane was a most effective insulation, but our main concern had always been to prevent roof leaks.
Mr. Scott monitored energy savings on 27 different buildings that had received SPF roofs from 1980 to 1984. The results were astounding. TAMU was able to recover the complete cost of the roof application through energy savings in an average of four and one-half years.
Quoted here is Mr. Scott’s conclusion, which is still shared by today’s Physical Plant Department:
From the time of construction, and throughout the life of the roof, built-up roofs were major maintenance and repair items. The experience that the Texas A&M University Physical Plant gained since 1974, when they began, indicates that no major problem, and very few minor ones exist in the polyurethane roof systems. As a result of this experience, all new construction includes the foamed polyurethane roof system. To date some 16 new facilities have this roof system totaling nearly one million square feet.
Another major advantage in a SPF roof system that does not exist with any other roofing system, is that SPF is a renewable system. While BURs and singly-plys must be removed and replaced after their usable lives, SPF roofs can be repaired and recoated to offer an indefinite life expectancy. Coupled with the energy savings and reduction in in-house maintenance costs, the SPF roofing system maintains a tremendous long-term cost efficiency advantage over all other roofing systems. Without question SPF roofs have a tremendous edge in preventing leaks and in detection and repair when one does occur.
The conclusion of today’s Physical Plant Department has not varied from the conclusion reached by Gerald Scott in 1985. We at the Physical Plant Department continue to monitor the progress of other roofing systems available. But at this time, no other roofing system can offer the leak free service, the ease of leak detection and maintenance, the energy efficiency, durability, or renewability provided by sprayed polyurethane foam roofs.
For more information about Pella Roofing & Insulation and our products and services, please feel free to contact us anytime at Office Phone: 319-223-5137 or 866-699-3967. For email inquiries, please write to ExteriorsUnlimited@eunlimitedinc.com