INTERFACE Newsletter of The Roof Consultants Institute #108 July 1985 A MESSAGE FROM THE PRESIDENT RCI, THE FORCE THAT CAN MAKE A DIFFERENCE Through my participation at two of the Regional Meetings held recently, I have been overwhelmed by the universal interest of roof consultants within our profession. We are generally concerned and strive to serve our profession the best that we can. In any profession, there are the few who blemish and tarnish the good reputation of the many. I am convinced that RCI represents a conglomerate of the cream of the crop of roof consultants. Some of the cream has not yet risen, but I feel confident that time and continued growth will bring those also into our organization. How can RCI make a difference? By making us better consultants. Through our Annual Conference and our Regional Meetings, I have seen consultants from across the country, consult with each other . Through this exposure we are learning from others experiences. “Would the individual who has used all 458 products offered on the market today (ref. NRCA “GUIDE”) in the thousands of combinations of decks, insulations, vapor retarders, etc., please step right up for your Susan B. Anthony silver dollar.” Of course, it is obvious that none of us can have experienced all materials and combinations available today. That is where RCI membership can internally “bridge the gap” that Bob Phillips talked about in an earlier issue of this Newsletter. It is as important to learn what not to do as it is to learn what to do. At the Regional Meetings, I stressed that one of the prominent characteristics of a professional is to know when he needs assistance from someone else. As the average RCI member firm is relatively small, the resource of assistance can be found within the RCI membership. We can each be a sounding board for each other. RCI is more that a professional organization: it is a fellowship of professionals with a common interest. AIA is for Architects; NSPE is for Engineers; NRCA is for Contractors; SPRI is for Manufacturers; CSI is for Specifiers. RCI IS FOR ROOF CONSULTANTS. Although you can be a member of each of the other organizations, none of those are specifically organized for and composed of Roof Consultants. RCI is the force that can make a difference in our profession and in our service to the Owner. The Owner is probably the common link between each of us in this organization. Whether we are a moisture surveyor, a forensic investigator, a specifier, a manufacturer, an equipment supplier, a manufacturer of roofing products, a testing laboratory, or combinations of all of these, the owner is the ultimate recipient of our services or products. When we look out for the best interests of the Owner, we in turn are looking out for the best interests of ourselves and our organization. RCI is the force that can make a difference. If you have joined us, we need your continued support and participation. If you are procrastinating, “times a wasting” and we need you. As Luke Skywalker said, “may the force be with you.” We are the force. EXPERIMENTAL ROOFING Introduction Experimental roofing comes in a variety of settings. The nearly 1200 2 RCI Interface, July 1985 square miles of low-slope roofing in the United States provide an extensive test bed for a large number of roofing experiments. More are likely. The National Roofing Contractors Association (NRCA) has projected a $7.5 billion roofing effort for 1985. Approximately 60 percent of the low-slope roofing effort will involve conventional built-up membrane roofing; however, there will continue to be more new applications of single-ply membranes and modified bituminous systems, products that show promise of performing well and capturing a larger share of the market. Many of the newer materials are more extensible and “forgiving” of substrate discontinuities. In addition, some newer felts and combinations of fiberglass and synthetic fibers (such as polyester) retain strength at extensions that could not be tolerated by materials composed of shorter fibers. The migration of roofing products from European to U.S. markets has helped proof test some materials. Environmental stresses vary with climate and latitude and, consequently, it is not surprising that products which may have served satisfactorily in some areas may not be completely suitable under other climatic conditions. Air-supported roofing (as in pneumatic structures) and tensioned fabric roofing is perhaps novel enough to be considered experimental. It is, however, engineered for specific applications and has been around for over two decades. It is not untested. These systems have many desirable features including reduced roof weight, translucence, and high solar reflectivity. Perhaps the largest application of such a system is in the roof of the airport terminal building in Jeddah, Saudi Arabia. The roof consists of Teflon-coated, tensioned, fiberglass. In the United States, instrumented fabric roofs which shed snow and melt ice have been installed. Misting of traditional low-slope roofs is likewise somewhat novel. When the roof surface (and air temperature) becomes hot enough, a mist of water is applied to the roof to cool the roof surface thereby reducing heat transfer and air-conditioning loads. Based on this introductory exploration of experimental roofing and on the number of new products available for low-slope roofs, it is appropriate to consider some guidelines for experimental roofing. Experimental roofing as discussed here does not mean untested roofing. Roofing products that are not tested to withstand the rigors of the environment where they are to be used belong in a special hazard category which we shall label “Buyer Beware.” Experimental roofing as discussed here will, first, include new or improved products that are rigorously tested by the manufacturer (Manufacturer Programs). Second, for the owner and contractor, experimental roofing may include combinations of materials and systems that are new to their experience and are, therefore, essentially experimental until they have been applied and evaluated. Some words of caution are appropriate regarding owners 1 experimental roofing programs (Owner Programs). Third, and finally, experimental low-slope roofing can eventually be evaluated, for many conditions, in a roof test chamber projected for construction by the U.S. Department of Energy at Oak Ridge National Laboratory (On the Horizon). Manufacturer Programs Programs of roofing materials development should involve significant experimental testing by the manuf acturer . Testing is accomplished by bench experiments (such as tests for strength, adhesion, and durability), by compact roof testing (such as in manufacturer’s test chambers where temperatures, loads, and moisture conditions can be varied), and by exposure in prototype roofs with companion studies to evaluate performance. Testing of experimental roofing materials and systems may be conducted under conditions that are known or presumed to acel erate degradation for the roof. Naturally, manufacturers differ in their approach to research; however, a serious commitment to experimental programs usually yields benefits. It can help with product design and quality assurance, and can minimize callbacks, uncertainties, and liability. The manufacturer’s staff may participate in ASTM technical committees and contribute to development of RCI Interface, July 1985 3 voluntary concensus standards. Their visibility in and contribution to technical committees is one indicator of corporate support for research and testing programs. Manufacturers* sales personnel should be adequately trained to answer technical questions or to contact other staff who can provide this information. Roofing products should be evaluated in a systematic and quantitative way to minimize uncertainties that occur when “testimonials of satisfied users” are forgotten. The factors of safety which are commonly used in other fields of engineering have not yet been identified for roofing. Owner 1s Programs Owners, including government agencies, should be interested in using new roofing products and systems where improved performance is likely. The conservative approach to selection of a new system may involve gradual replacement of a portion of the traditional systems of roofing by a system which the owner, his engineer, or architect, is less familiar with. Systems for re-roofing or retro-fitting may be installed and observed comparatively to avoid buying a “pig in a poke.” Few agencies or owners are willing to invest in a roofing system for which little data and field experience are available. The sheer number of products and combinations available to choose from compounds the difficulty of making a selection. When in doubt, contact the NRCA roofing materials Guide. Innovation and experimentation should be encouraged where potential for improvement exists. Several suggestions are offered for owners who wish to try a new roofing product. -Complete a thorough background study including review of relevant literature. -Visit roof sites where the material has been installed. -Contact owners and contractors to identify potential problems and “sensitivities” of construction. It is preferable to talk to owners and others who have applied the materials or systems on roofs similar to yours. -Identify potential remedial measures, costs, liabilities, and responsibilities during this planning phase. Don’t experiment if you are not willing to monitor, inspect and maintain the roof. Keep records of installation costs, problems and repairs. On the Horizon The U.S. Department of Energy and the Oak Ridge National Laboratory have developed plans and specifications for a Roof Test Center that will be located in Oak Ridge, TN. The Center will eventaully be a national user facility after completion of an initial agenda of fundamental experiments on roofing performance, especially thermal performance. The roof test specimens will include typical low-slope roof systems consisting of structural decks, thermal insulation, and membrane. Special emphasis will be placed on whole system performance. There is a significant potential for saving energy in roofing. The roof is, after all, the only building component that the owner normally schedules for renewal approximately every 20 years. Owners have found that increased thickness of insulation added during roof retrofitting can save operating costs, particularly for large, low buildings where the roof constitutes a large portion of the above-ground thermal envelope. The operating energy saved exceeds the energy embodied in manufacturing thermal insulation and membrane materials. It is hoped that continued development by manufacturers, educated awareness by owners and specifiers, and dissemination of non-propri etary information obtained from research will enable experimental roofing to become durable and cost-effective roofing – as a matter of practice. (NOTE: The article is by Dr. Herbert Busching, Chairman RCI Board of Regents, for Roofer Magazine June 1985 issue.) METAL ROOFING – Part II PRE-FORMED METAL ROOFING Pre-formed metal roofing has not been accorded the artistic recognition which has been afforded copper. Quite the contrary, it seems to have been developed for utilitarian purposes and has since maintained a more commercial than artistic status. Due to the 4 RCI Interface, July 1985 technological processes involved with manufacturing these materials and their protective finishes, usage of pre-formed metal panels has been basically restricted to recent times. Serious utilization of pre-formed metal panels did not occur in the United States until after 1900. For example, corrugated galvanized iron panels have been used since the turn of the century on a wide range of structures including outhouses, sheds, Second World War Quonset huts and other military structures, as well as innumerable commercial installations currently being produced by the metal building manufacturing industry. One of the major drawbacks of using pre-formed metal roofing panels in the past has been their tendency towards seam leakage. This problem was largely addressed when the metal building manufacturing industry began to incorporate standing seams into design for pre-formed metal roofing systems. The engineering principles of standing seam metal roofing can be traced as far back as the Renaissance, or beyond. However, soft, light-guage metal roofing with standing seam construction was not seriously accepted in the American market place until around 1934 at the Chicago World’s Fair. As a wider variety of architectural designs for metal buildings began to rapidly evolve, an enormous amount of engineering effort was devoted to developing improved metal roofing systems for these structures. Pre-formed metal roof panels with standing seams began to emerge as a superior design throughout the 1970’s and remains a dominant factor within the industry today. Like copper, pre-formed metal roofing has often been subject to problems such as thermal movement, electrolytic corrosion, seals, fasteners, etc. In my experience, I have found two additional problems associated with pre-formed metal roofing which are not common to the softer, light-guage metals. First, the protective finishes applied over ferrous substrates can break down, and may range from breakdowns in electroplated galvanized finishes, to primer failures. I have also observed failures within 20 year rated, factory-baked acrylic finishes. Second, I find more workmanship problems experienced with pre-formed metal roofing than with copper roofing. To me, the reason for this appears obvious. An entirely different breed of workman is generally employed to install a standing seam copper roof as opposed to one who is engaged to fasten together a system of metal roof panels. I do not find this to be an acceptable situation. There are manifold opportunities for roofing mechanics to be factory trained to install metal roofing systems. All that is required is a commitment of time and money by the roofing contractor to assure that his personnel have the proper knowledge of the system on which they are working. Unfortunately, some of the poorest performing metal roof systems I have inspected were constructed by workmen employed by a metal building contractor, and they had no concept of the principles involved with good roofing practice. Several months ago, I inspected two off ice/warehouse buildings for one of our clients. Both structures were built less than 3 years ago with concrete masonry unit walls and pre-formed metal roof panels. Both structures “leaked like a sieve”. With the interior lights off, and through fiberglass batt insulation, I could see daylight streaming through numerous open seams in the metal roof. Further inspection revealed that the roofing panels had been installed incorrectly with improperly torqued fasteners and “stitch-screws”. There was also evidence that numerous fasteners had been “wallowed-out” by over-torquing during installation. Further, an inadequate application of sealant material had been placed between metal panel side-laps. The roofing contractor who had been “maintaining” these buildings apparently did not comprehend the basic principles of metal roofing. His solution to open seams created by under-torqued fasteners and wallowed-out fasteners, as well as fractured sealant applications, was lots and lots of mastic. ..sometimes with a little reinforcing membrane. ..sometimes without. One of my single, largest areas of consternation as a professional roofing consultant lies with roofing and sheet-metal contractors who appear to believe that two pieces of metal can be effectively fastened together and kept RCI Interface, July 1985 5 waterproof by being stuck together with asphalt mastic cement or caulking. At the above project the asphalt cement baked in the heat, photo-oxidized, lost its original ductility and finally cracked due to thermal movement of the metal panels. Assuming that the engineering of design and materials is correct and that all of the component parts have been carefully and accurately assembled, metal roofing remains one of the strongest and most reliable roofing systems presently available. I do not know why the metal roofing industry has not literally doubled within the last generation, but I strongly expect that it will do so prior to the end of the 1980’s. In my opinion, copper metal roofing materials will remain restricted to elaborate and impressive structures, due to the comparatively high cost of these metals. I envision, however, a potential explosion of pre-formed metal roofing in the more commercial ly-oriented construction market as soon as the engineering of these systems has been further refined and perfected. GENERAL On a practical note, like every other roofing system known to mankind, metal roofing should not be considered a a panacea which automatically results in eliminating all roof-related problems. As with any form or discipline, it is extremely important for the designer to know and understand the materials with which he is working to assure that they are not inappropriately used. Understanding weaknesses and limitations is equally as important as comprehending the strengths of a given material or system. In designing a roof, I tend to initially classify and consider a number of prospective materials for a new project by whether or not their strong qualities will be suitable for my intended purposes. After I have assembled a collection of materials and/or systems, I begin to eliminate them one by one, according to their weaknesses and inadequacies. Limitations of metal roofing systems and materials become as critical to performance as their strong points. For example, a leading manufacturer of copper roofing products attempted to discover why come copper installations failed while others, installed many years earlier, continued to provide satisfactory service. Failures were detected in installations where the same methods of assembly were used that proved satisfactory on other jobs. It was learned that the failures resulted from movement of the metal from repetitive cycles of temperature change. A primary factor concerning reduction of failures has been found to be recognition of the importance of compressive strength in sheet metal. Compressive strength is the ability of a particular member or section to resist compression loads (as a column) without deformation of the shape by the application of external forces. Experiments indicate that shape and gauge play an important part in resistance to buckling, and that three factors should be considered fundamental to promoting long service in copper installations. First, weight and temper of the copper. Second, design of sections and distribution of expansion joints. Third, efficiency of transverse joints. Observing only one or two of these factors will not suffice. All three should be controlled to provide for expansion and contraction without exerting failure-loads on the copper. One of the most important single factors in the successful design of a metal roofing system concerns usage of the correct gauge. Engineers have concluded that sheet metal materials act to transmit stress in proportion to their gauge and shape regardless of the metal material. It is now understood that cold rolled copper is more resistant to buckling than soft copper and that the heavier the gauge the greater the rigidity. These factors are also found to directly affect seam efficiency whether they are standing seams, batten seams or horizontal seams. These factors apply whether or not metal sheets or linear metal details are involved. One of my priorities for sheet metal work is that an acceptable mechanical connection should be achieved prior to waterproofing any metal joint. Normally, this rule would just be considered good common sense. However, I find far more mitered coping cover corners and mitered 6 RCI Interface, July 1985 surface-mounted counterflashing corners which have been sealed with globs of asphalt mastic or acrylic-based sealant materials than I find made with proper construction and waterproofing techniques. Sheet metal details need the same degree of attention whether part of a built-up roofing system or part of a metal roofing system. As a designer of roofing systems, I am faced with two irrefutable facts every time I deal with metal sheets and metal details. First, metal sheets come to an end; they are not infinite things that just continue on and on. This means that on a recurring basis, I will be forced to either deal with terminations or joints. If I am wise, I will address each of these conditions with specific designs which have been engineered for the purpose. Second, metal is a relatively unforgiving material in that it does not exhibit the plasticity or flow properties of many bituminous materials. This means that I must provide some means of waterproofing at every perimeter or termination using materials which are compatible and recommended for sheet metal details and metal roofing systems. If I am to be successful in such an unforgiving scenario, I must fully understand the benefits as well as the deficiencies of each component part of the material with which I am working. I must also comprehend the physics and dynamics of my design and the effect upon each material . In my opinion, the average roofing professional has not been willing to accord metal roofing any more than “second-class citizen” status. I continually see lists of roofing materials published which reference BUR, El asto-Pl astic Single-Ply, Elastomeric Single-Ply, Bituminous Single-Ply, Shingles, Polyurethane Foam, Liquid Applied Coatings and Cold-Process, but reference to Metal Roofing is seldom made. I find that more-often-than-not, metal roofing is relegated to the position of simply being a component part of a metal building. To those of you who are reading this article while sharing the same thought, I respectfully suggest that you begin to rapidly do your homework. Old prejudices and biases should be cast aside in light of the technological advances and cost efficiencies which have been realized during the 1980’s. The Metal Building Manufacturers Association (MBMA) stated that around 315 million square feet of metal roofing systems are currently being sold each year and that the growth trend is decidedly upward. I submit that this much activity demands attention from any roofing professional who wishes to remain within the mainstream of our industry. (Note: the above is Part II of an article written by D. B. Hales for the May 1985 issue of the Roofer Magazine. Mr. Hales is the National Secretary of the Roof Consultants Institute, Ed.). RSI-“ON THE ROOF” In the March 1985 issue of RSI Mr. Fricklas stated, “Roofing consultants are also looked at with some skepticism, part of this is because there are no established guidelines or qualifications for the credentials of a ‘roofing consultant.’ Since there is. no professional license and no exact standard, consultants tend to encompass a wide range from highly qualified people to those with skills that are no better than the average building owner.” In response, Mr. Richard P. Canon, President RCI, has forwarded the following letter to the editor of RSI. Regarding Mr. Fricklas’ March column, the Roof Consultants Institute (RCI) is pleased to convey to your readers that our organization has established guidelines and qualifications for the credentials of a Roof Consultant. Chartered in 1983, RCI established as one of our primary goals the minimum requirements an individual should have completed or attained to use the title “Roof Consultant.” There are, of course, many individuals and firms who have not yet met these qualifications. However, RCI, as a viable group of dedicated and concerned professionals, strives through our recruitment and exchange of information to aspire to develop the same credentials among Roof Consultants that NRCA has developed among roofing contractors. It is recognized that there will probably never be “exact standards” for consultants to adhere to or to follow just as there are no “exact standards” for contractors to follow. Area RCI Interface, July 1985 7 practices impact consultants just as they do contractors. RCI has, however, taken major steps through our implementation of minimum requirements for Roof Consultants. RCI is studying the procedures for developing a professional licensing program for Roof Consultants. Jurisdiction would probably ultimately fall under each state’s auspices (similar to Professional Engineers) and would therefore result in an extensive, meticulous, and predictably slow evolution. RCI has also established and approved other working documents such as a Standard of Ethical Practice and has in Committees areas of interest such as Criteria and Methodology for Non-Destructi ve Moisture Surveys and other topics. We encourage interested readers to write or call RCI National Headquarters, 7424 Chapel Hill Road, Raleigh, North Carolina 27607 (919) 859-0742, for additional information regarding Roof Consulting and our organization. RCI REGION MEETINGS HELD June 1985 Richard P. Canon, PE, RCI National President, Robert W. Phillips, Jr., RCI National 2nd Vice President and Membership Committee Chairman, and the Region Directors are to be commended for their work in organizing and conducting these excellent Region Organization Meetings. REGION ONE MEETING June 21, 1985 Newark, New Jersey Robert F. Martin, Region Director Robert W. Phillips, Jr, National 2nd Vice President of RCI, assisted Mr. Martin in conducting the meeting, and Mr. Sidney Koch made an excellent presentation as guest speaker. 23 attendees participated in several lively discussions. At the close, attendees indicated by a show of hands their overwhelmingly positive repsonse to RCI and its goals. REGION TWO MEETING June 14, 1985 Jacksonville, Florida Lee Meyer, AIA, Region Director Richard P. Canon, PE, National President of RCI, and Mr. Meyer conducted the meeting. John Harris of Manville Corporation presented a provocative and timely topic as guest speaker. 20 attended the meeting. All attendees expressed an enthusiastic interest in RCI. REGION THREE MEETING June 28, 1985 Chris Clarke, Region Director Dallas, Texas Richard P. Canon, PE, National President of RCI, conducted the meeting. Mr. William M. Murphy, Attorney, made an enlightening presentation on legal aspects as guest speaker. All 24 attendees stated a positive interest in RCI and its goals. REGION FIVE MEETING June 14, 1985 Newport Beach, California Felix L. George, Architect, Director Michael J. Kelleher, National 1st Vice President of RCI, assisted Mr. George in conducting the meeting. The meeting concentrated on discussions concerning RCI progress and goals. 15 attended the meeting. All made a positive expression of support for RCI and its goals. REGION FOUR J. Jefferson Scott, Region Director A Region 4 meeting has been proposed to the Executive Committee for October, 1985. PLAN TO ATTEND – SECOND INTERNATIONAL SYMPOSIUM ON ROOFING TECHNOLOGY – September 18-20, 1985 Washington, DC The theme is “A Decade of Change and Future Trends in Roofing”. Papers will be presented by leading authorities on roofing technology from all over the world. MEMBERS MASTER FILES How are your C. E.U.’s? Have you returned your Form RCI-2, 2/26/85, RCI Member Master File Update? Please complete and return your Form RCI-2 just as soon as possible, in order for RCI Headquarters to keep your Master File up-to-date as to professional qualifications, C. E.U.’s earned, training, and experience, etc. FROM A MEMBER “Thanks for the very informative 8 RCI Interface, July 1985 April Newsletter. The message from the new president, Dick Canon, was great. We agree with him completely. The “DON’T CARE” attitude is the biggest problem we have today” John A. Lance, Jr. , RCI FROM A PROSPECTIVE MEMBER “I’m impressed! For the past year I have been receiving issues of RCI INTERFACE and I admit that you certainly fill a void in my perception of the roofing industry. — would like to be affiliated with RCI both to learn and to help wherever I might” Donald A. Berg, PE CALL FOR PAPERS We urge you to join the members who have contributed their knowledge and expertise in providing past articles for the RCI INTERFACE and for the “Consultant’s Column” in ROOFER Magazine. CALL OR WRITE THE RCI NATIONAL OFFICE NOW to indicate interest in participation. RECENT NEW VOTING MEMBERS Peter J. Monterose Architect/Roof Consultant Stittville, NY Walter F. Pruter W. F. Pruter Associates Los Angeles, CA Carl Kuhn Construction Resources, Inc. Middleburg Heights, OH For full information on the Roof Consultants Institute and a membership application form, write to William C. Correll, AIA, Executive Director, Roof Consultants Institute, 7424 Chapel Hill Road, Raleigh, NC 27607 or call 919/859-0742. R C I The Roof Consultants Institute 7424 Chapel Hill Road Raleigh, North Carolina 27607 919/859-0742 NEWSLETTER
