President’s Message November 1989 RCI is maturing. The Board of Directors is taking long strides in implementing the bylaws and activating committees. In doing so, we are finding the bylaws need some work. At the National Convention in March, your Board of Directors will consider some major revisions. The relationship between the member and the Board, between committee and the Board, the role of the Executive Committee, and the role of the non¬ registered professionals are all being challenged. We do need to remember this is a volunteer association and you are the association. RCI needs the input of everyone so the direction of RCI is the result of consen¬ sus among the majority of members. Least we forget the purpose of RCI, our objectives are listed below: This is a volunteer association — you are the association. 1. An organiza¬ tion to represent the roof consulting, non-destructive roof testing, and waterproofing con¬ sultants. 2. An organization acting as a clearinghouse for in¬ formation relevant to the roofing industry. 3. An organization actively involved with other in¬ dustry-related association including the National Roof¬ ing Contractors Association (NRCA), the American Institute of Architects (AIA), the National Society of Professional Engineers (NSPE), the American Stand¬ ards for Testing and Materials (ASTM), the American Society of Civil Engineers (ASCE), and the Construc¬ tion Specifications Institute (CSI). continued on page 2 A Caution For Structural Metal Roofs Lyle Hogan, PE, CRC Abstract Metal roofing systems are a legitimate selection in some instances. Desig¬ ners have made recent strides in fitting such con¬ struction to both new and re-roof markets. In trying to gain market share in the “flat roofing” sector, a dis¬ turbing tendency is gaining acceptance. The tendency is to construct metal roofing systems with very shallow slopes. We pinpointed this in recent studies as the most frequent cause of leaks in metal roof systems. This paper explores findings gathered during several such studies. Photographs document problems associated with shallow slope metal roofs. Photograph 1 Metal Roof Classifications Some classify structural metal roofs as those with slopes of 1/4 inch per foot and greater. 1 Structural metal roofs re¬ quire no subdeck. Metal roofs having slopes of 3 inches per foot and greater are more visible. Many classify these as architectural metal continued on page 4 Newsletter of The Roof Consultants Institute 2 message from the president continued from page 1 4. An organization with an active committed mem¬ bership, each member having an active role on one or more of the working committees. YOUR ATTENTION PLEASE: Asbestos in Roofs You will receive 90 minutes of update at your con¬ vention. Dick Canon and Joe Hale will present the latest on this issue. The NRCA has informed us they would appreciate air-monitoring results from our projects. You can make the reports generic by blocking out your client’s name, etc. NRCA will provide you with copies of their data at the cost of reproduction. Coordinate your submittals and requests with your na¬ tional headquarters. (Paula Bakerat 1-919-859-0742). Wind Uplift RCI did participate in the Uplift Workshop in Oak Ridge, TN, in November. Bob Phillips and Paula Baker Many RCI mem¬ bers attended the Wind Uplift Workshop in Oak Ridge, TN did a super job representing RCI by assisting at the registra¬ tion desk. Ben Hales, Alan Kidd, and many others par¬ ticipated by con¬ tributing time and effort in the committees. Many RCI members at¬ tended the sessions gaining tremendously from the in¬ formation presented. RCI is proceeding with a proposal to assist in the field efforts to observe the damage of wind. This effort is being spearheaded by Joe Hale. Joe is currently being assisted by Phil Dawson and William Kivette. Alan Kidd will carry the RCI proposal to the ad hoc Wind Uplift Committee on behalf of RCI. We have also committed our resources to help begin to address the identified research needs. You can help and have immediate impact by sending a letter to one or both of the individuals listed below stating your sup¬ port for their efforts in the area of wind uplift research. You can also donate money toward the purchase of the first dynamic wind uplift apparatus in the United States. The apparatus will likely be fashioned after the English version called BRER WULF. The machine will be part of the work at Texas Tech and Colorado State. Kishor C Mehta Professor of Civil Engineering Texas Tech University Institute for Disaster Research P.O. Box 4089 Lubbock TX 79409-1023 (803) 742-3476 Robert N. Meroney Professor of Civil Engineering Colorado State University Department of Civil Engineering Engineering Research Center Ft. Collins CO 80523 (303)491-8574 National Convention You should have received your attendee brochure. Reserve your place at the convention. There is an enor¬ mous amount of interest in this convention and we want you to have the first opportunity to attend. Register today and include the one-day, add-on Metal Roofing Seminar. NRCA/NIST International Symposium 1991 The National Roofing Contractors Association and the National Institute of Standards and Technology are looking for several things from RCI members: 1. Your name, if you have specialized experience in a particular area of roofing industry. You may be called upon to review proposed articles. Please call George Kanz, 1-800-798-0227, if you are interested. If you have specialized experience in wind uplift, please volunteer your credentials now. 2. Your response to the call for papers for this sym¬ posium. You will be receiving a notice in the next few weeks. 3. Your support of the symposium by attendance. continued on next page Newsletter of The Roof Consultants Institute 3 Hurricane Hugo Texas Tech and NRCA visited the devastation wrought by Hugo. They are asking for assistance. If you are part of roof investigations and/or repair/replacement in the Hugo area and want to share this informa¬ tion for the betterment of the roofing industry, please contact Tom Smith at NRCA (1-312-318-6722). RC1/NRCA Liaison Committee The committee has met twice for a total of eight hours in the past year and discussed many issues. After the last meeting, a “rap” session was held. I firmly believe we have to hold more of these “rap” sessions. NRCA needs to better understand where we are and we, in turn, need to understand NRCA. A detailed report of activities of the committee will be available at the convention. Among items of special note: 1. RCI Asbestos Committee Chairperson will meet with the NRCA Asbestos Committee Chairperson. 2. NRCA will provide a pool of speakers for the RCI asbestos course. 3. We are working on a joint document describing the role of the contractor and the consultant. New Catalog Every once in a while things change and if you have comments, let’s tell people. A manufacturer has com¬ pletely rewritten and reorganized its information into specific sections. The sections include products/application/ safety/warranty/maintenance/repair/design. Let’s tell Firestone what we think about its new system. Extra Effort Required – Top Priority Take time to enjoy the fruits of your labors – spend time with your families this Holiday Season — Have the Happiest of Holidays! George Kanz, PE, CRC Shive-Hattery Engineers PO Box 1803 Cedar Rapids IA 52406 319/364-0227 Asbestos Committee Update increased NESHAP enforcement Joe Hale Region 2 Director Asbestos Committee Chairperson In a nationwide effort, the EPA filed 13 lawsuits in one day last August 22 to demonstrate its in¬ creased commitment to en¬ forcement of the federal asbestos standard in¬ stituted under the National Emissions Standards for Hazardous Air Pollutants (NESHAP) of the Clean Air Act. At the same time, EPA announced a new enforcement policy for asbestos regulation, including increased fines, as well as using for the first time its authority to ban two asbestos abate¬ ment contractors with asbestos violations records from receiving federal funds. Thirty-four defendants, including institutions, companies and individuals, were named in the civil enforcement suits with violations charges dating back to 1984. These suits were chosen be¬ cause they covered a broad area of ac- Thirty-four defendants, including institutions, companies and in¬ dividuals, were named. tivities subject to enforcement by NESHAP involving demolition and renovation projects in various geographical locations and diversity of type and size. Under NESHAP, EPA or specified state or local projects that involve asbestos and asbestos materials must be removed in all cases where laboratory tests indicate a minimum amount is present. Also required are proper work procedures such as wetting and bag¬ ging to prevent fiber release and proper transporting and dis¬ posal. EPA estimates half of the more than 100,000 demolition and renovation projects done in this country each year violate asbestos NESHAP. While in the past, EPA’s enforcement of NESHAP has been poor, due to inadequate resources and staff, officials sought changes in enforcement and policy to improve NESHAP compliance. The August lawsuits and policy an¬ nouncements were among the results of these changes. Tougher penalties and publicity of the lawsuits are hoped to continued on page 8 Newsletter of The Roof Consultants Institute 4 structural metal roofs continued from page 1 roofs. Architectural-style metal roofs require a continuous interior deck. Mansards, cornices, equipment screens, chev¬ rons, and ornamental roofs are architectural metal roofs (photograph 1). This article will explore structural metal roofs only. Photograph 2 Cross-section of Roofs Studied We studied a group of 18 month old metal roofs. These roofs had about two dozen documented leaks dating from completion. These case histories also contain several metal roofs decades old with 2 to 3 inch per foot inclines. These roofs were in surprisingly good condition. There were a few troublesome skylights and gutter joints. Why Design Metal Roofs with Shallow Slopes One argument for low slopes is the volume of interior air space generated by higher slopes. A client was considering a virtually flat standing seam system because of this. We asked about the actual cost of that air space. He could not give a reasonable answer. Interior leaks resulting from “flat work” have a cost of their own. This cost is in the form of incon¬ veniences to occupants and interruption of operations. Desig¬ ners must weigh any possible disadvantage of a large volume of interior air space against the confidence gained at greater roof slopes. Photograph 2 depicts a cosmetically appealing metal roof with commendable slope. Metal Roofs over Large Floor Spaces When buildings are to enclose vast floor spaces, desig¬ ners tend to nest up multiple smaller roofs. Such nesting re¬ quires sharing common gutters which drain internally. We have had unsatisfactory experiences with such shared or common gutters. Recurring leaks characterize these con¬ figurations. We especially caution against such design when light gage sheet metal serves as the conduits. Photograph 3 Thermal Movement Sheet metal panels may experience a far greater tempera¬ ture swing than the range of a given day’s ambient tempera¬ ture. This is due in part to conductivity and, depending on color, absorption. Because of this, metal roofs frequently suf¬ fer from thermally-induced movement. This is called rack¬ ing. One can actually hear racking as the surface responds to solar gain or loss. On roofs installed before the introduction of sliding clips, racking causes conventional Z-shaped pur¬ lins to rotate (roll). This behavior tends to separate panels from fasteners with corresponding wear at fastener holes. 3 Improperly tooled fasteners are particularly prone to back¬ out (photographs 3 and 4). These conditions may exist in any metal roof. The prudent designer will check the need for ade¬ quate slope. Newsletter of The Roof Consultants Institute 5 Lap Problems Two metal sheets lapped and lying tangent are prone to wick water, even uphill. Water may migrate uphill a sig¬ nificant distance. This is due to capillary action. Photographs 5 and 6 show this. Proper selection and use of caulk and sealants is critical. Any fasteners downslope of the caulk line may admit water into the roofing system. Photograph 5 Once contractors install the panels, assessing lap quality is difficult. The diagnostician is unable to see the critical part and its positioning. Inserting a business card within the lap region (photograph 7) will sometimes identify concealed caulk or tape locations. Marginal slope designs compound the potential for leaks from this or other discrepancies. We acknowledge that it is possible to join metal pans Photograph 6 together in one of several rib configurations in a functional, waterproof lap. We also know of many factors which can compromise good lapping/seaming. Among such factors are: Variations in structural members (photograph 8) Misalignment of components (photograph 9) Malfunctioning automatic seamers Marginal skill of mechanics Burning gaskets from fasteners during overtooling Photograph 9 Newsletter of The Roof Consultants Institute 6 Deformation Under Loads Light gage metal panels are prone to deform under even moderate loads. Some panel configurations are particularly vulnerable to deformation from little more than “stepping in¬ correctly.” This is due to certain engineering properties of the panel and is beyond the scope of this paper. Simple geometry, however, can illustrate how damage from point loads varies with slope. This behaves according to the sine of the vertical angle subtended against the roof slope. Point loads inflict more damage at lower slopes than at higher slopes. Deflection resulting in permanent deformation may cause ponding (photographs 10 and 11). Ponding water on a metal roof should be unacceptable. Photograph 10 Complex Systems add to Problems The complexity inherent in metal roof systems adds to the frustration of chasing leaks. Contractors usually install a blanket of fiberglass insulation backed with vinyl beneath metal deck sheets. Manufacturers represent such a blanket as being a vapor retarder. Water entry into the roofing assemb¬ ly, for whatever reason, may migrate laterally. It finally drips onto the floor beneath some imperfection in the vapor retar¬ der detailing. An inspection directly above such a spot on the floor seldom reveals the actual point of water entry. Photograph 12 depicts a condition of saturated insulation blanket. Summary Many knowledgeable roofing professionals postulate that the susceptibility for any given roof discrepancy to leak varies inversely with slope. That is, low slope, high chance; high slope, low chance. Designing and constructing metal roofs with shallow slopes could then be percieved as a quan¬ tum leap in the wrong direction. We call out to the vendors of metal roofing systems to ac¬ knowledge that positive slope should be a prerequisite for all roofing systems, including their own. Designing and con¬ structing such roofs will permit the end user to enjoy the life cycle and weathering benefits of metal membranes without recurring, random and unpredictable leaks. References 1. “RSI”, September 1988. Paul Nimtz, page 42. 2. “RSI”, August 1989. Dick Fricklas, page 8. 3. “Roof Design”, June 1984. Fred Stevenson page 37. Lyle Hogan, PE, CRC Trigon Engineering Consultants, Inc. P.O. Box 18846 Greensboro, NC 27419-8846 919-668-0093 Newsletter of The Roof Consultants Institute 7 ROOF CONSULTANTS INSTITUTE FIFTH NATIONAL CONVENTION CHICAGO, ILLINOIS MARCH 19-21, 1990 Newsletter of The Roof Consultants Institute 8 increased NESHAP enforcement continued from page 3 encourage compliance. Systems are in existence for review¬ ing construction license applications, landfill records, and bid requests for demolition and renovation projects and EPA is making better use of these. NESHAP inspections have in¬ creased almost 2.5 times between 1985 and 1988, and civil enforcement action has increased accordingly. Criminal NESHAP violations have also been filed. Penalties are authorized by the Clean Air Act for as much as $25,000 per violation per day. The previous guideline of $4 per square foot or linear foot has been increased to $20 per foot of asbestos materials involved. Penalties will now also be levied on such factors as the severity of the offense environmentally and the defendant’s compliance history. Separate penalties will be imposed for separate violations in¬ cluding wetting, notification or improper disposal. Serious NESHAP offenders will be placed on a list of those banned from receiving federal contracts or funds. Under this previously announced policy, two contracting companies were the first to be listed: Big Apple Wrecking Co., Bronx, NY and J.Y. Arnold Co., Central City, KA. These stronger enforcement measures increase the poten¬ tial for NESHAP violators to be caught and penalized. It is hoped they will provide a deterrent to violation. Source: “As¬ bestos Abatement Report”, Vol. 3, No. 7, Sept. 4, 1989. Two New RIEI Seminars Offered During 1989-1990 The first new seminar is a “Roofing Roundtable.” The seminar objective is to provide a forum in which attendees and RIEI faculty can openly discuss current situations in the roofing industry. Student proposed subjects and roofing problems will also be covered. Hand-out materials will in¬ clude reprints from industry associations and standard¬ making bodies, as well as from recent periodicals. The emphasis will shift to meet the interest of each group of at¬ tendees, but the program will cover commercial roofing such as BUR, single ply, modified bitumens, spray-in-place polyurethane foam, cold process, hot polyester and metal roofing systems. Developments in Codes, FM and UL re¬ quirements, asbestos handling, ASTM and other standards, industry recommendations and new texts will be covered. The second seminar to be introduced is on “Rooftop Quality Assurance.” The seminar objective will be to obtain a quality roofing system. It will focus on the assembly of components into a finished roofing system and will enable at¬ tendees to specify, communicate and verify correct installa¬ tion. The curriculum will include a review of structural requirements, review of attachment methods and application techniques. Key quality assurance indicators and recordkeep¬ ing techniques will also be covered. Inspection and installa¬ tion of details, terminations and surfacings and requirements for temporary roofs, nightly tie-offs, permanent connection of old and new roofing systems will be covered. We will also discuss what works with roof cuts versus visual observa¬ tions. Recommended practices and publications from ASTM, SPRI, NRCA and PFCD will be detailed. These seminars will only be offered one time during the RIEI 1989-1990 year. They will be held in Vail, Colorado on April 2-4, 1990. Seats are limited and early registration is strongly recommended. For further informa¬ tion or to register, please contact RIEI at: 14 Inverness Drive East, Building H, Suite 110 Englewood, Colorado 80112 (303) 790-7200 RIEI Requests Quality Assurance Check Lists RIEI is seeking RCI members who would be willing to share quality assurance check lists for possible use in the “Rooftop Quality Assurance” seminar (see above). Generic check lists or check lists for proprietary roof systems would be appropriate and would be greatly appreciated. Please send check lists to RIEI at the above address or to RCI Headquarters. Duro-Last Sponsors Winter Issue This issue of INTERFACE is made possible through the sponsorship of Duro-Last Roofing, Inc., 525 Morley Drive, Saginaw, Michigan, 48601, (800) 248-0280/2160 N.W. Vine Street, Grants Pass, Oregon, 97526, (800) 356-6646. The Duro-Last Roofing System consists of fabricated single-ply roofing membrane, stacks, curbs, parapets and fas¬ cia. The system, which is designed to meet your individual needs, reduces welds up to 80% and virtually all of the criti¬ cal flashing seams. The roof system will be shipped no later than five (5) working days from the time it is ordered. The “Interface Newsletter” is published by the Roof Consultants Institute. Copyright© 1988 Roof Consultants Institute. All rights reserved. Please address all submittals, subscription requests, advertising, etc. to the Roof Consultants Institute, 7424 Chapel Hill Road, Raleigh, NC 27607. Telephone 919/859-0742. The RCI logo, the name ”Interface Newsletter” and the title “Certified Roof Consultant” abbreviated “CRC” are the property of the Roof Consultants Institute and must not be used without permissionus. Newsletter of The Roof Consultants Institute
