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January/February 2010 Volume 33 Number 1

Technical Bulletin
Laminated Shingles & Water-Shedding Roof Systems for Lower Slopes
by WSRCA Steep-Slope Committee

 WSRCA wishes to advise you of technical information, along with some recent research data, in order to provide you with some prudent cautions regarding the use of laminated-asphalt shingles on roof slopes less than 4:12 (i.e., 4” of vertical rise per 12” of horizontal run [33.3%]).  We trust that you will find this information helpful in your business.

         For many years there has been an issue with various “steep-slope” (i.e., watershedding) roofing materials being promoted, by some select groups within the industry, on roofs with slopes less than 4:12.

General Background Information

         During the late 1990’s the National Roofing Contractor Association (NRCA) published information in The NRCA Roofing and Waterproofing Manual, specifically in the NRCA Steep Roofing Manual that suggested cautions when asphalt shingle roofing is specified by designers for application on slopes less than 4:12.  A quote from that 1996 Asphalt Shingle Section of the Manual is as follows, which may be found under the heading “Roof Slope Limitations and Underlayment Requirements”:  “B. Asphalt Shingles may be applied:  On roof decks having a slope of 4” per foot (33%) or more, if a minimum of one layer of No. 15 asphalt saturated (non-perforated) ASTM D-226 or ASTM D-4869 felt is applied horizontally (in

“shingle” fashion) to serve as the underlayment.  On roof decks having a slope of 3” per foot (25%) or more, if two layers of No. 15 asphalt saturated non-perforated ASTM D-226 or ASTM D-4869 felt are applied in ‘shingle’ fashion as the underlayment, with 17” (432mm) exposure and 19” (483) side lap.  Note:  NRCA does not recommend application of asphalt shingles, at maximum exposure, on slopes less than 3” per foot (25%).  Some manufacturers will allow application of asphalt shingles on lesser slopes.  However, more stringent underlayment specifications and reduced shingle course exposures, as well as careful consideration of roof layout, valley details, and climatic conditions are thought necessary by NRCA.  NRCA suggests that interlocking shingles, laminated shingles, and no cut-out-strip shingles be applied on roofs with slope of 4” per foot or greater.”

         As the NRCA Steep Roofing Manual progressed from the 4th Edition to the 5th Edition, those statements of cautions are more strongly worded.  For example:  “Ice dam protection membranes should not be relied upon to keep leaks from occurring…,” “Some manufacturers…, but NRCA does not recommend use of asphalt shingles on slopes less than 4:12…”

         However, in conflict with the concept of NRCA’s written cautions when specifying or applying shingles on slopes less than 4:12, the first (1st) through fourth (4th) Editions of the Asphalt Roofing Manufacturers Association (ARMA) Residential Roofing Manual stated that asphalt shingle roofing could be installed on slopes as low as 2:12.  For many years that document has not made a distinction regarding the roof slope(s), various types of asphalt shingles, and the potential performance differences of various shingles (e.g., 3-tab, laminated, t-lock, no cut-out, strip shingles, etc.) in relation to roof slope.

         This conflicting industry information between manufacturers’ set criteria and experienced contractor-based suggestions and/or recommendations may be relatively new for some individuals in the United States roofing industry.  However, the Western States Roofing Contractors Association’s technical committees have, over time, monitored various reports of asphalt shingle and other steep-slope water-shedding roofing issues.  At this time WSRCA’s Steep-Slope Roofing Committee wishes to advise the industry of problem jobs where laminated-asphalt shingles, and even some cases with 3-tab shingles - have been specified on minimal sloped roofs - and problems have developed.

         Recently, reported post-roofing issues have developed and caused problems for roofing contractors and others involved in several of the projects - as such, Western States Roofing Contractors Association desires to relay pertinent news to its members and others in the design and construction industry.

         This technical bulletin explains general background information, the nature of the research that WSRCA and others have undertaken, and the results of that testing and research.  Thus WSRCA offers new recommendations to architects, designers, general contractors, and roofing contractors that work in the Western Regions of the United States.

Recent Laboratory Testing

         Because of recent problem jobs, where asphalt shingles or other water-shedding roofing materials have been specified on generally low-sloped roofs, and leaks have developed, WSRCA and others undertook research to study the issue.  The testing included construction of mock-up roofs, which proved that a build up of overlapping materials, including underlayment layers, and shingle layers, coincided to lower the slope of the already low-slope roofs.

Design, Construction, and Related Legal Developments or Issues

1.         Water-shedding Roof Systems Need Sufficient Slope to Shed Runoff:  Deck-design slope and deck-constructed slope can have matching attributes in that they may be constructed as designed with respect to materials, methods and slope; however, when these slopes approach 3:12 the water-shedding asphalt shingle roofing system is minimally prepared to shed water before wind-driven rain and capillary action combine to overcome the water-shedding capabilities of the asphalt shingle roofing system.

2.         Relatively Thick Laminate Shingles Result in Loss of Slope:  In most cases laminated shingles are multiple layers of asphalt-based material assembled with two-to-three layers on the downslope portion of the shingle, and only one layer on the upslope half, generally to facilitate installation.  The effect of this “wedged-shaped” watershedding element installed on a lower-sloped roof deck results in a loss of slope and impairment of the roof’s water shedding performance.  This loss of slope on a roof system with a 6:12 sloped roof deck may be insignificant, as to the shingles performance.  However, when the resultant loss of slope occurs on a 3:12 sloped roof system, which is already approaching the lower limits of its ability to shed water rapidly, the slope degradation can be significant enough to allow wind-driven rain, snow melt, and even rain water to enter the roof assembly.

3.         Build-up of Layered Underlayments and Multi-layer Underlayments Reduce Slope:  Multi-layer underlayment laps can reduce slope even further on this already challenged water-shedding roof system.  When laminated-asphalt shingles are utilized on roof decks with a 3:12 slope, there are areas of the roof where the designed and constructed 3:12 slope has degraded, due to build-up of materials and shingle deflection or distortion resulting from exposure to the sun, to approximately 1:12 (as well as some isolated locations that may be less than 1/2:12).  Rooftop conditions, such as described above, can compromise the basic capabilities of a water-shedding roof system, and should be recognized as inappropriate design, and not representative of good roofing design practices.

4.         Relatively Thick- and/or High-profile Capped Nails Reduce Slope:  High profile capped (e.g., relatively thick or raised-profile plastic capped) nails sometimes used in underlayment attachment design and underlayment application further reduce the slope as they create raised areas on a water-shedding roofing system already operating in the lower ranges of its functional capabilities.

In Conclusion

         WSRCA believes that this account of lack of roof slope, and the specification of laminated-asphalt shingles on slopes less that 4:12, and the testing and information regarding same, will help to eliminate confusion in the industry regarding current roof-related documents that have had conflicting recommendations for slopes less than 4:12.

WSRCA’s Current General Recommendations

July/August 2009 Volume 32 Number 4

Western Roofing Expo 2009 Recap
Thousands Converge in Reno for 35th Annual WSRCA Convention
by Marc Dodson, editor

 It all came together in Reno, Nevada, June 14-17, 2009, for the Western States Roofing Contractors Association (WSRCA).  Many were a little concerned when the association made the decision to go to Reno a few years ago following a string of successful Las Vegas conventions.  Later, when the construction economy started going downhill, more than a few became very concerned.  However, the Western Roofing Expo 2009 turned out better than expected.  The event experienced a great turnout with an enthusiastic attitude from both exhibitors and attendees.  Even the weather cooperated and the temperatures hovered in the 80s.
         The Peppermill Resort & Casino in Reno was the site of this year’s extravaganza.  According to the WSRCA, about 2,000 convention-goers converged for Western Roofing Expo 2009.  Roofing professionals from throughout the West were on hand to experience the three days of seminars, golf and sporting clays, exhibits, demonstrations, and industry camaraderie.

 Trade Show
         The trade show featured with 152 companies staffing 260 booths.  Adding interest to the floor this year were Corvettes of various years, a 1932 Ford Coupe hot rod, the ABC Supply sponsored A.J. Foyt Indy racecar, and the raffle prize BMW convertible.  In all, seven cars dotted the trade show floor.  The Expo featured local, regional, and national companies displaying their latest products and services, many available only in the Western market.  The majority of the exhibitors we talked to were very pleased with the turnout and the convention.
         Chuck Chapman, president of the WSRCA, was on hand to cut the obligatory ribbon to open the show.  Once open, the show remained a bustling center of activity until the final closing hours.
         The Davis Memorial Foundation raffle took place during the final hour of the trade show.  The foundation is the charitable arm of the WSRCA and awards scholarships to deserving students each year.  The grand prizewinner of the BMW 128i convertible was Frank Lawson, Jr., The Lawson Roofing Company, San Francisco, Calif., who purchased only two raffle tickets this year.

 Seminars
         Seminars this year included:  Green Roof Design 101 Introductory Course; TRI Installer Training Workshop; TRI Specialist Training Workshop; Knowing the Numbers; Exhibitor Showcase Seminars; GAF/CARE Workshop:  Energy Efficient Roofs; Credit:  From Cradle to Grave; Tile Roofing 2009 Manual Updates; Leadership in Energy and Environmental Design (LEED) and the Roofing Contractor; Secure Your Own Roof:  Powerful Estate and Succession Planning; GAF/CARE Workshop:  TruSlate - The Hassle Free Slate Roofing System; Workshop:  BURSI (The Better Understanding of Roofing Systems Institute by Johns Manville); International Building Codes Updates (ICBO); Growing Your Business in a Down Economy - It’s All About Maintenance; The Art of the Deal:  Negotiating and Conflict Resolutions; and Coating Systems:  Where They’re being Used, How They Should be Used, and Why You Should be Installing Them!  Additionally, back for the third year, were the Exhibitor Showcase seminars.
         Two of the best-attended seminars were:  Credit:  From Cradle to Grave; and Leadership in Energy and Environmental Design (LEED).  Both seminars played to packed houses, which is even more impressive when you consider that they were held concurrently with other presentations.
         On June 17, the Roof Consultants Institute (RCI) Region IV presented seminars in conjunction with the WSRCA convention.  Seminars this year included:  Available Solar Technologies, Installation, Economics & Financing Options; Rooftop Photovoltaics - Questions Roof Professionals Need to Ask; Design Problems in Solar Voltaic Installations; and Green Roof Design and Installation 201.

 Annual Luncheon
         The speaker at the annual luncheon this year was dynamic business leader and author Mark Sanborn.  Sanborn has published extensively in the areas of leadership, change management, teamwork, and service strategy.  His current release, You Don’t Need a Title to be a Leader, inspires leadership at every level, regardless of formal title while his international best-seller, The Fred Factor, delivers an insightful guide to creating value and meaning to your work, life, and the lives of those you impact.
         Sanborn delivered a riveting talk filled with humor and anecdotes that kept the audience glued to their chairs.  Sanborn was deemed by many as one of the best WSRCA speakers in recent years.

 Awards
         Recognizing those that have gone above and beyond the call of duty has become a tradition with the WSRCA.  At the Legislative Luncheon, WSRCA president Chuck Chapman honored both Bruce Hunter-Dushel and Michael Trotter as Board Members of the Year for their efforts on behalf of the association. At the Opening Luncheon, the infrequently bestowed Outstanding Service Award was presented to John Cleasby, Cleasby Manufacturing.  Cleasby was honored for his continuing dedication and service to the Western roofing industry.  Congratulations gentlemen!

 Scholarship Fund Raisers
         The Davis Memorial Foundation Tournaments again hosted two fund-raising sporting tournaments prior to the convention.  On Sunday, June 14, the golf tournament was held at the University of Nevada owned Wolf Run Golf Club.  The Sporting Clays Tournament was held concurrently at the Sage Hill Shooting Club.
         A silent and not-so-silent auction was held during the President’s Reception, which also netted the foundation several thousand dollars.  Additionally, the raffle of the BMW also raised funds for the foundation.
         The Davis Memorial Foundation awarded scholarships this year to:  John Sampietro, Petaluma, Calif. (Henris Roofing Co.); Lauren Lyons, Dixon, Calif. (CertainTeed); Alex Carpenter, Sherwood Oregon (Columbia Sheet Metal); and Geoffrey Bloom, Bothell, Wash. (Allied Building Products).  The McKennon winner this year was Kent Hakola from Snyder Roofing, Renton, Wash.

 New Officers
         The newly elected officers this year are as follows:  president, Charles Chapman, Central Roofing of Arizona, Phoenix, Ariz.; senior vice president, Christian Madsen, Madsen Roof Co., Sacramento, Calif.; vice presidents, Don Fry, Fry Roofing, San Antonio, Texas; Travis Nelson, Brown Roofing, The Dalles, Oregon; Bill Asbury, Quality Tile Roofing, Boise, Idaho; Michael Trotter, Front Range Roofing, Greeley, Colo.; and immediate former president, Sharon Keppler, Evergreen Roofing, White City, Oregon.
         In his opening address to the gathering, president Chapman thanked everyone for their support and vowed that the association would continue as a leader in industry education and information dissemination.
         Next year the WSRCA will hold its 36th annual convention and trade show in Las Vegas, Nevada, June 20-23, 2010, at the Paris Hotel & Casino.  For more information, contact the WSRCA at (800) 725-0333.