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NRCA Research on SPF Roofs
National Roofing Foundation Surveys SPF Roofs

In the most comprehensive roof survey ever performed the National Roofing Foundation has examined SPF roofs from Eau Claire, WI to Houston, TX and from Los Angeles to New York City. With Dr. Rene Dupuis acting as principle investigator, the foundation has been examining in-place foam roofing, predominantly with service ages ranging from ten to twenty years. This survey includes field observations and random sampling as well as extensive laboratory analysis.

The report provides some interesting insight into a roofing system that is still widely misunderstood in many roofing circles. Dick Fricklas, Technical Director for The Roofing Industry Educational Institute, discussed the need for such a survey in his monthly column for RSI magazine.

Mr. Fricklas states, "Many readers of this column are roofing contractors and consultants who may be very knowledgeable on BUR, modified bitumen and single-ply systems, but who have never sprayed foam. When asked to look at an existing foam system... They're more likely to tell the owner to tear the foam roof off and put down something they do know how to handle."

Mr. Fricklas goes on to state "For building owners, dubious because of the 'horror stories' they've been told, the field survey should be reassuring. Earlier work done by Dr. Dean Kashiwagi at Arizona State indicated many foam roofs have lasted 20 years or more and appear to last indefinitely if maintained. Kashiwagi also discovered that owners have been extremely satisfied with the performance of their foam roofs. Should the (NRF) survey be as positive as Kashiwagi's earlier work, perhaps some skeptics will be willing to take another look."

Dr. Dupuis expects many members of the roofing community to be surprised by the NRF findings. According to Dr. Dupuis, "most people think a foam roof is a foam roof is a foam roof. They see an application performed by unskilled labor using improper materials and they assume that all foam roofs are the same. Our survey is demonstrating that the high end specification of SPF is equal to any other premium roof system."

At last year's NRCA convention in San Diego Dr. Dupuis stated that "SPF roofing systems appear to have a very high degree of sustainability. Properly maintained with periodic recoating these systems have an indefinite life expectancy."

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Navy Study
SUMMARY OF NCEL TECHNICAL NOTE N-1815

"INVESTIGATION OF SPRAY-APPLIED POLYURETHANE FOAM ROOFING SYSTEMS-II"

Naval Civil Engineering Laboratory- Port Hueneme, California
Sponsored by Naval Facilities Engineering Command
Conducted by: R.L. Alumbaugh, E.F. Humm, and John R. Keaton
July 1976- January 1986

Background: This study was initiated by the NCEL at the request of NAVFAC in a continuing effort to reduce maintenance and repair costs of the extensive roofing systems at Naval installations. This study was limited to Spayed Polyurethane Foam (SPF) and Coating systems, and was intended to generate data that provides guidelines for coating systems to protect SPF materials used in the roof system.

The principal objectives of this investigation were to determine how long the candidate SPF roofing system perform satisfactorily when exposed to the weather and which of the candidate systems were superior. The SPF systems were exposed to three different climatic conditions: A seashore site at Port Hueneme, CA, a desert site at China Lake, and a mountain site at Pickle Meadows in the high Sierras.

Their experience had shown that if the SPF is properly applied to a suitably prepared substrate, the performance of the system is primarily dependent on the performance of the protective elastomeric coating system. That is, with a high quality foam, if the coating performs well, the SPF roofing system as a whole can generally be expected to perform well.

The performance of the coated SPF panels was monitored periodically at the three sites. The performance characteristics of the various systems were determined at periodic intervals by visual inspections and ratings. The characteristics considered related primarily to the coatings and included adhesion, blistering, checking, cohesion, cracking, flaking, peeling, pinholing, and hail and bird damage. All of these factors were then considered in assigning an overall performance rating as follows:

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.

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Texas A&M Study
A COMPARISON OF CONVENTIAL AND SPF ROOFING SYSTEMS

Sam Cohen
Project Management Supervisor
Engineering Design Services
Physical Plant Department
Texas A&M University

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:

1. Seams are one of the major sources of leaks in roof systems and SPF roofs are totally seamless.
   
2. Water does not travel laterally in SPF roofs as it can in BUR or single-ply roofs. A leaks in the top membrane of a BUR or single-ply roof will create the spreading of water, saturating the insulation and causing multiple interior leaks. With SPF, even if a hole is punched through the entire two-inch membrane, water movement will be restricted to the hole. In most cases repairs can be made with a tube of caulk.
3. Because the SPF roof is lightweight, permeable and fully adhered, normally an old roof does not need to be removed in order to apply a new one. If underlying areas of saturated insulation are found, minimal tear-off may be required.
4. The SPF roofing is less disruptive to students and faculty since tear-off is minimal. Also, projects are accomplished faster because the application is quieter, quicker and requires far less laborers.
5. Roof mounted units, penetrations, curbs, and parapets can receive a seamless monolithic application because SPF is spray applied. BUR and single-ply roofs require flashing materials with sealants which frequently result in leaks.

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.

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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