Are You Meeting Thermal Insulation Code Requirements?

Photo 1. Conditions such as this, in which the fastener plates melt the snow, visually demonstrate the heat loss that is a known entity to roof installers and knowledgeable roofing professionals.

You may have overheard conversations such as this:

New Building Owner: “You promised energy conservation and savings.”

Mechanical Engineer: “We sized the mechanical unit based on the code required effective thermal value.”

New Building Owner: “But why are my cost 30 percent above your estimates and I am needing to run my units constantly and they still barely maintain a comfortable environment?”

Mechanical Engineer: “We have checked all the set points and systems and they are all working, albeit with a bit of laboring. We don’t know why there is not enough heat.”

New Building Owner: “Well, someone is going to have to pay for this!”

Scenarios and liability questions like this are being repeated across the northern North American continent, and to mechanical engineers, architects and owners, the cause is a mystery. Perhaps they should have talked to seasoned roofing professionals and consultants. They could’ve told them that many mechanically attached roofs, incorrectly promoted and sold as energy-saving systems, were actually energy pigs. One only needed to walk a mechanically attached roof with a few inches of snow on it to see the heat loss occurring. It doesn’t take scientific studies and long-winded scenarios to prove this — just get up on the roof and see it. (See Photo 1.)

Photo 2. When a light dusting of snow blew off this 2 million-square-foot facility in central Illinois, every single mechanical fastener and insulation joint could be identified by the ice visible at their locations. This roof needed to be replaced due to condensation issues several years after installation at a cost of more than $10 million.

I spoke on this topic back in 2007 at the RCI Cool Roofing Symposium. I always like being a soothsayer, and several recent studies are demonstrating and attempting to quantify this energy loss that most roofers could tell you was there.

For years the NRCA suggested a loss of thermal value of 7 percent to 15 percent through the joints in a single-layer insulation application and through mechanical fasteners used to secure the insulation. (The NRCA has since removed this figure and suggests that professionals be consulted to determine thermal heat loss.) The NRCA recommended a cover board to reduce this effect. This was at a time when roof covers were predominantly BUR, modified bitumen or adhered single plies. The upsurge in mechanically attached single-ply membranes, brought on by low-cost installation and the promise of energy savings, changed the game. No one was asking, if there could be a loss of 7-15 percent when mechanically attaching insulation, what could the effective R-value loss be when we install thousands of fasteners and plates 12 inches on center (or less) down a membrane lap seam? Gee, haven’t we seen that before?

Code Requirements

The code and standard bodies — ICC, IECC, ASHRAE — have been repeatedly raising required thermal insulation values over the past decade in an attempt to conserve energy; that is their intent. They listened to astute designers and

Photo 3.This is close-up of the roof shown in Photo 2. Heat loss through the screws and fastener plates and through joints in the single layer of insulation melted the snow. The water froze when the temperatures dropped and the ice was revealed when a light wind pillowed the membrane and the remaining snow blew away.

prescribed two layers of insulation, and then again to determine the minimum R-value and not allow averages. The intent is clear. The required R-value per ASHRAE zone is to be achieved.

Their goals were laudable, but not all roof systems achieved the in-place R-values required. So, this article is in part an attempt to educate code officials and explain the need for a change.

Words can explain the phenomenon of thermal loss, but photos are worth a thousand words, and since my editor has told me that I cannot have a 4,000-word article, I leave it to the photos to do the talking. (See Photos 2, 3 and 4.)

Scientific Studies

In their Buildings 2016 article titled “Three-Dimensional Heat Transfer Analysis of Metal Fasteners in Roofing Systems,” Singh, Gulati, Srinivasan and Bhandari (Singh) studied the effect of heat transfer through thermal bridging (mechanical fasteners) in various roof assembly scenarios.

Their study exposes a shortfall in many standards that have as their goal a reduction in energy loss through building envelope systems through prescriptive approaches. For roofing assemblies, standards prescribe a minimum R-value, but they do not take into consideration the heat loss that happens though metal fasteners. There are no guidelines or recommendations in regards to thermal loss, including the loss of heat through roof system fasteners. It’s actually ignored.

Figure A: The effect of mechanical fasteners below the roof cover in mechanically attached roofs is not negligible as considered by general standards. As can be seen here for systems 1A and 1 B, in which mechanical fasteners are used in the lap seams of the roof cover (systems 3A and 3B have the fasteners below a layer of insulation), the actual thermal value loss caused by mechanical fasteners can be as high as 48 percent, as seen in system 1A with a high density of mechanical fasteners. As the mechanical fastener density decreases (1B), the heat loss also decreases. Thus, a correlation appears to exist in which heat loss due to thermal bridging is proportional to the fastener density.

The results of the Singh study, as seen in the graph (Figure A), show that the effects of thermal shorts, e.g., mechanical fasteners used to secure the roof cover, is not negligible. In fact, thermal shorts can result in a loss of 48 percent of the effective value. Read that again! The thermal value of the roof insulation layer on which the mechanical engineer has in part sized the mechanical equipment — and which the owner is counting on for significant energy savings — could be about half of what was assumed. Add in gaps and voids, and the loss in the effective R-value could top 50 percent. What that means is that to achieve the code required R-30, say in Chicago, mechanically fastened roof systems need to have R-45 in the design to meet the effective code required R-value. This last sentence is for the code bodies — are you listening?

The value of this study cannot be underestimated, as thousands of buildings have been constructed since its publication that would not meet an effective R-value check in a commissioning study.

Changing the Code

The energy inefficiency of mechanically attached roof systems in ASHRAE zones 4 and above has been known to roofing crews for decades. Now, with the requisite scientific studies completed, the codes need to be revised to reflect the inherent thermal loss through mechanical fasteners. Additionally, studies from Oak Ridge National Laboratory highlight the energy increase required with inherent air changes below the membrane, confirming the need for air/vapor barriers on the deck on mechanically attached roof assemblies. (See “The Energy Penalty Associated with the Use of Mechanically Attached Roofing Systems,” by Pallin, Kehrer and Desjarlais.)

Photo 4: Heat loss also occurs through adhered roofs when the insulation is mechanically attached.

As a starting point for code groups and officials, I suggest the following code revisions:

  1. State that if a mechanically attached roof cover is being used that the prescribed thermal R-value shall be increased by 50 percent.
  2. State that if a mechanically attached roof cover is being used that an air barrier below the insulation must be used and that it shall be fully adhered to penetrations and roof perimeters.

Closing Thoughts

The goal of energy conservation is a laudable one. The American Institute of Architects’ goal of zero-energy building by 2030 will never be met until real-world empirical information can be presented at code hearings. (For those of you who do not attend code hearings or know the process, information is usually disseminated in two-minute sound bites without documentation.) This lack of information sharing is a travesty and has resulted in numerous code changes that have been detrimental to the goal of energy savings. Time has come for a new way of thinking.

Ponding Water Basics: Proper Drainage Design and Low-Slope Roofs

Roofing professionals install a new asphalt roof on the Broward County Stephen Booher Building in Coral Springs, Florida. Photo: Advanced Roofing Inc.

A low-slope asphalt roofing system is cost effective, durable and reliable. Multiple layers of weatherproof membranes protect a building, its residents and the property it houses. There are a few design elements that will help building owners get the most from their roofing system. Managing ponding water is essential to properly maintaining a roof.

Ponding water is defined as the water which remains on a roof 48 hours or longer. Water may accumulate on a low-slope roof due to rain, snow or runoff from rooftop equipment. Ponding water can have major negative consequences, regardless of the type of roofing system. Proper design, installation and maintenance of roofing structures can prevent this condition and its associated problems.

The adverse effects of ponding water on roofs can include:

  • Deformation of the deck structure:Ponding water can substantially increase the load on roof decks. As water accumulates, deck deflections can increase, thereby resulting in additional ponding water, which could compromise the structural integrity of the deck.
  • Damage to the roof surface:Ice formations develop and move constantly with changes in temperature. This movement can “scrub” the roof membrane to such an extent that considerable physical damage to the membrane can occur.
  • Growth of algae and vegetation:When water stands for long periods of time, algae and vegetation growth will likely occur, and may cause damage to the roof membrane. Additionally, vegetation can clog drains and cause additional ponding.
  • Accumulation of dirt and debris in the ponding area:Dirt, debris, and other contaminants can affect and damage the membrane surface. The can also lead to clogged drains.

Proper design and installation are crucial factors in roof system performance. This photo shows an Atactic Polypropylene (APP) modified bitumen membrane being applied by torch to a low-slope roof. Photo: ARMA

Ponding water may lead to accelerated erosion and deterioration of the membrane surface that can result in failure of the roof system. Allowing even relatively small amounts of moisture beneath the roof membrane may reduce the thermal efficiency of the insulation. More importantly, moisture intrusion can cause serious damage to the deck, insulation, and membrane as well as the building’s interior.

The Asphalt Roofing Manufacturers Association (ARMA) recommends that roof designs provide adequate slope (minimum of ¼ inch per foot) to ensure that the roof drains freely throughout the life of the building and to thereby avoid the effects of ponding water. Model building codes also require a minimum ¼ inch per foot slope for new construction projects, and require positive drainage for re-roofing projects. These requirements are intended to prevent water from ponding on roof surfaces.

Managing Ponding Water

Here are a few best practices to manage ponding water:

  • Adequate sloping should be taken into account during the design process. A roof’s structural frame or deck should be sloped, and drainage components like roof drains and scuppers should be included in the design.
  • In addition, secondary (or emergency) drains may be required by local plumbing codes to help reduce the risk of a structural failure due to clogged drainage systems. Talk to your roof membrane manufacturer and/or roof system designer to determine the proper location of these components.
  • If a deck does not provide the necessary slope to drain, a tapered insulation system can be used. A combination of different approaches — single slope, two-way slope, and four-way slope — is often used to achieve the necessary slope and to allow for moisture drainage.
  • Additionally, crickets installed upslope of rooftop equipment and saddles positioned along a low-point between drains, can help prevent localized ponding in conjunction with a tapered insulation system.
  • Building designers and owners should work with contractors and roof manufacturers to determine which methods are best and appropriate for a roof assembly’s long-term performance, whether it’s a new construction or re-roof project.

The NRCA Roofing Manual: Membrane Roof Systems—2015, states the following: “NRCA recommends that designers make provisions in their roof designs for positive slope.”

The manual spells out that slope generally is provided by:

  • Sloping the structural framing or roof deck
  • Designing a tapered insulation system
  • Proper location of roof drains, scuppers and gutters
  • A combination of the above

By following the proper drainage practices detailed above, building owners can positively impact their low-slope roofing system and help to ensure it will remain durable and reliable throughout its service life.

To obtain specific information about ponding water on particular products and systems, contact your roof material manufacturer. For more information about low-slope asphalt roofing systems, visit www.asphaltroofing.org.

NRCA to Hold Educational Events for National Safety Stand-Down

As part of its annual support for the National Safety Stand-Down to Prevent Falls in Construction taking place throughout the U.S. from May 7-11, 2018, the National Roofing Contractors Association (NRCA) is partnering with the Occupational Safety and Health Administration (OSHA) to host two educational events aimed at reducing fall fatalities in the roofing industry.

The latest statistics from the Bureau of Labor Statistics (BLS) show 92 workers in the roofing industry died in 2016 from falls that occurred as they were doing their jobs. Those numbers reflect 92 families that have been changed forever by the loss of a loved one — a spouse, father, mother, son or daughter.

Organized by OSHA, the National Safety Stand-Down is an effort to focus company and worker attention on the significance of fall hazards in construction and emphasize the importance of effectively implementing fall-protection systems on every project.

On May 7, NRCA will offer a free webinar at 1 p.m. (CDT), that will kick off with an introduction from Dean McKenzie, OSHA’s director of the directorate of construction. It will focus on how to use a job hazard analysis (JHA) and other pre-job resources and activities during the job and after its completion. A roofing company’s safety culture and its effects on fall prevention also will be addressed.

The second event, a live half-day fall-prevention awareness seminar, will take place Tuesday, May 8, from 8 a.m. until noon at NRCA’s headquarters in Rosemont, Ill. Topics will build off the previous day’s webinar, including performing a JHA, discussing and demonstrating hazards associated with rescuing a fallen worker while suspended by his or her fall-arrest system, key fall-protection regulatory requirements and case studies from attendees’ fall-related experiences. All attendees are encouraged to listen to the webinar before attending the seminar.

Job foremen, superintendents, roofing contractors and safety directors are encouraged to attend both events.

For more information, visit www.nrca.net.

NRCA to Launch its ProCertification, Worker Training Initiative in 2018

To address the great need for skilled workers in the roofing industry, NRCA is launching a national worker certification initiative, ProCertification, later this year. The program will provide those interested in entering the industry with a clear career path based on industry-specific training courses and earned credentials.

ProCertification is comprised of two separate components: Training and Certifications.

Training

ProCertification training programs will teach installation skills to roofing field employees in roof system installation, waterproofing, rooftop solar, and repair and maintenance.

Because every roofing contractor operates his or her company differently and uses different manufacturers’ materials, the purpose of ProCertification is to teach comprehension and skills based on industry standards and best practices presented in The NRCA Roofing Manual. Roof system installers will be directed to follow instructions of their foremen, who are responsible for directing crews to adhere to manufacturers instruction and company practices.

ProCertification training programs to be released in 2018 are: basic roofing skills; low-slope decks, insulation and flashing concepts; and thermoplastic single-ply roof system installation.

Trainers throughout the U.S. will be qualified by NRCA and trained to help installers learn and practice skills necessary to successfully complete ProCertification training

Certification

Certification through this program enables experienced roofing professionals to demonstrate they can perform the work to industry standards. Participants will be able to earn certifications in all major roof system, waterproofing and rooftop solar installations, as well as roof system repair and maintenance.

Hands-on skills of ProCertification participants will be verified by NRCA Qualified Assessors. Online training for assessors will be available summer 2018.

For more information, visit www.nrca.net/NRCA-ProCertification.

NRCA Announces National Roofing Week Will Take Place June 3-9

To raise awareness of the significance of roofs to every home and business, the National Roofing Contractors Association (NRCA) has announced National Roofing Week will take place June 3-9.

Celebrated each year during the first full week of June, National Roofing Week serves as a reminder that the roof is one of the most important components of every structure. It is the first line of defense against natural elements, such as rain, snow or wind, yet it is often taken for granted until it falls into disrepair.

National Roofing Week also promotes the good deeds of the roofing industry and stresses the value of professional roofing contractors and the importance of making informed decisions about maintaining or replacing any roof system. During National Roofing Week, NRCA encourages its members to participate by engaging in their communities and informing the public about the essential role roofs and professional roofing contractors play in every community.

NRCA also will be sharing its members’ stories through its various social media outlets, its Roof Scoop blog and Professional Roofing magazine. Members throughout the country are encouraged to share their stories of charitable giving, crew and staff appreciation, and signature roofing projects with NRCA.

In addition, NRCA members are encouraged to promote the importance of what roofing professionals do by encouraging children to participate in NRCA’s 2018 Children’s Art Contest. The contest is open to children in grades 1-8 whose relatives work for NRCA member companies (all NRCA member companies are eligible). Entries will be accepted until April 16.

National Roofing Week 2018 is sponsored by ABC Supply Co. Inc.; A.C.T. Metal Deck Supply; Chem Link; Duro-Last; FlashCo; GAF; Insulfoam; International Roofing Expo (IRE); National Women in Roofing; KM Coatings; Polyglass; and Soprema.

Additional information about National Roofing Week can be found at www.nrca.net/National-Roofing-Week.

The Roofing Industry Alliance for Progress Announces 2018 Gold Circle Awards Winners

The Roofing Industry Alliance for Progress has awarded five members of the Roofing Industry Alliance for Progress and the National Roofing Contractors Association (NRCA) with the prestigious Gold Circle Award during NRCA’s 131st Annual Convention held Feb. 6-8 in New Orleans. The award recognizes outstanding workmanship, including unique roofing-related jobs, programs and services.

The 2018 Gold Circle Awards were presented in the following categories:

Outstanding Workmanship: Low-slope

Winner: Klein Contracting Corp., Doraville, Ga., for AT&T Midtown Center, Atlanta
Finalist: Nations Roof LLC, Rowlett, Texas, for Tyson® Foods Vienna Processing Facility, Vienna, Ga.

Outstanding Workmanship: Steep-slope

Winner: American Roofing & Metal Co. Inc., Louisville, Ky., and Steinrock Roofing & Sheet Metal Inc., Louisville, for Fayette County Courthouse, Lexington, Ky.
Honorable Mention: Flynn Southwest LP, Commerce City, Colo., for University of Denver’s Daniel Felix Ritchie School of Engineering & Computer Science
Finalists: Charles F. Evans Co. Inc., Elmira, N.Y., Bradford County Courthouse-Phase 1, Towanda, Pa. Wagner Roofing Co., Hyattsville, Md., Carter’s Grove Plantation, Williamsburg, Va.

Innovative Solutions: New Construction

Winner: Flynn Southwest LP, Commerce City, Colo., for University of Denver’s Daniel Felix Ritchie School of Engineering & Computer Science
Honorable Mention: Roofing Solutions LLC, Prairieville, La., for St. George Catholic Church, Baton Rouge, La.

Innovative Solutions: Reroofing

Winner: Wagner Roofing Co., Hyattsville, Md., for Bethesda Metro Center, Bethesda, Md.
Honorable Mention: American Roofing & Metal Co. Inc., Louisville, Ky., and Steinrock Roofing & Sheet Metal Inc., Louisville, for Fayette County Courthouse, Lexington, Ky.

Safety Preparedness and Performance

Winner: Wagner Roofing Co., Hyattsville, Md., for Bethesda Metro Center, Bethesda, Md.
Finalists: Charles F. Evans Co. Inc. Elmira, N.Y., for Bradford County Courthouse-Phase 1, Towanda, Pa. Douglass Colony Group Inc., Commerce City, Colo., for Colorado State Capitol, Denver

For more information, visit www.roofingindustryalliance.net.

NRCA Announces Significant Updates to Roof Wind Designer Online Wind-Load Calculator

The National Roofing Contractors Association (NRCA) has announced the update of Roof Wind Designer, an online wind-load calculator intended to provide roofing professionals with an easy way to determine a roof system’s design wind loads for many commonly encountered building types subject to code compliance.

The free web-based application has been updated to reflect the significant changes made to ASCE 7, “Minimum Design Loads and Associated Criteria for Buildings and Other Structures.” Changes include basic wind map changes; new roof zone layouts; and updates to pressure coefficients.

Roof Wind Designer also added the ability to perform wind load calculations for the 2016 version of ASCE 7 and enables users to choose between three versions of the standard: ASCE 7-05, ASCE 7-10 and ASCE 7-16.

The 2016 version of the application can also be used on flat buildings up to 160 feet using the standard’s Chapter 30 Part 4: Buildings with 60ft < h ≤ 160ft (Simplified), giving users a wider range of buildings that can be calculated. Design wind loads for other applicable buildings are calculated pursuant to simplified low-rise procedures for each standard. Roof Wind Designer initially was developed in cooperation with the Midwest Roofing Contractors Association and North/East Roofing Contractors Association. For more information visit www.roofwinddesigner.com.

Core Contractors Inc.’s Alan Baird Awarded The Roofing Industry Alliance for Progress’ 2018 Best of the Best Award

The Roofing Industry Alliance for Progress has announced Alan Baird, foreman of Core Contractors Inc., Denver, as the recipient of the Best of the Best Award. Baird was announced as the award winner at the National Roofing Contractors Association’s (NRCA’s) 131th Annual Convention held Feb. 6-8 in New Orleans.

The Best of the Best Award, which is co-sponsored by Professional Roofing magazine and OMG Roofing Products Inc., Agawam, Mass., is awarded each year to one of the recipients of the Alliance’s Most Valuable Player (MVP) Awards program, which recognizes and honors outstanding roofing workers from various U.S. regions.

Baird also was a 2018 MVP Award winner for outstanding on the job performance and other noteworthy contributions and activities.

“He is a shining example of what the true bar of excellence is within his company and within his community,” said Josh Kelly, vice president and general manager of OMG Roofing Products, when announcing Baird as Best of the Best. “He constantly impresses his managers and peers through self-driven educational training, hard work, a positive attitude, public service, and a heart of pure gold.”

As the 2017-18 Best of the Best Award winner, Baird will be featured in Professional Roofing’s April 2018 issue.

For more information about the MVP Awards program or next year’s nominations, contact Bennett Judson, the Alliance’s executive director, at bjudson@roofingindustryalliance.net.

Roofing Industry Stakeholders Meet Elected Officials on Roofing Day in D.C. 2018

More than 400 roofing industry stakeholders from 47 states are in Washington, D.C., on March 7, meeting with their elected officials as part of Roofing Day in D.C. 2018. Led by the National Roofing Contractors Association (NRCA) and more than 20 partner associations and organizations, the event is an unprecedented effort to elevate the image of the roofing industry and share its message with lawmakers on Capitol Hill.

Roofing Day in D.C. 2018 is among the top 10 percent of all national legislative fly-in events and the largest advocacy event dedicated solely to the roofing industry. Participants will visit with members of Congress and discuss three issues on which there is broad consensus within the roofing industry: regulatory reform, workforce development and immigration reform. About 85 percent of Congress will hear from roofing industry stakeholders during the event.

“NRCA is excited to lead this industrywide effort to bring the message of the roofing industry straight to our elected officials,” said Reid Ribble, NRCA’s CEO. “Thanks goes out to the more than 400 stakeholders who travelled to D.C. today to advocate for our great industry.”

For information, visit www.nrca.net.

Auburn University Wins The Roofing Industry Alliance for Progress’ Fourth Student Competition

The Roofing Industry Alliance for Progress has announced the team from the McWhorter School of Building Sciences at Auburn University, Auburn, Ala., was selected as the first-place winner of The Roofing Industry Alliance for Progress’ fourth annual student construction management competition, which took place during the National Roofing Contractors Association’s (NRCA) 131st Annual Convention held Feb. 6-8 in New Orleans.

Members of the winning team were Jordan Edwards, Alexander Gomez, Jason McCay (team captain), Hannah Redifer and faculty advisor Lauren Redden.

Redifer also was selected as the recipient of the competition’s first Best Individual Presenter from among all the finalist teams and received an iPad.

The competition was part of an educational partnership with schools of construction management around the U.S. The four finalist teams selected to present in New Orleans were McWhorter School of Building Sciences at Auburn University; Department of Construction Management at Colorado State University, Fort Collins, Colo.; M.E. Rinker Sr. School of Construction Management at the University of Florida, Gainesville, Fla.; and Bert S. Turner Department of Construction Management at Louisiana State University, Baton Rouge, La.

The goal of the partnership is to raise awareness of the roofing industry by developing roofing-related curriculum that can be incorporated into existing construction management undergraduate degree programs, exploring scholarship programs for both students and faculty members and developing an internship program with interested Alliance members.

Teams participating in the competition were presented with a problem statement: Create a company to bid on installing a roof system on the Audubon Aquarium of the Americas in New Orleans. Each team was required to research the project, review the plans and specifications, and assemble a full estimate and proposal to submit a qualified bid package. For this project, it was important to decide on the correct application methods, show overall roofing knowledge and illustrate the team was prepared to undertake the project.

Oral presentations were given at the convention Feb. 7.

Auburn had the highest cumulative score for their presentation as Summit Roofing. The team had a thorough understanding of site logistics and schedule; exhibited a strong safety plan that included planning, training and execution; and spent a great deal of time preparing the presentation.

The team from Colorado State University was awarded second place in the competition. Team members were Majoney Bajwa, Kyle Bloesser, Sam Hughes (team captain), Ben Jacobs and faculty advisor Nick Rubino.

Auburn University received a team trophy and a $5,000 L.B. Conway scholarship for their school. The team trophy and individual awards were presented during NRCA’s Awards Ceremony and Cocktail Reception March 2.

Colorado State University received a team trophy, a $2,500 scholarship for its school and individual awards.

For more information about the Alliance student competition, contact Bennett Judson, the Alliance’s executive director, at (800) 323-9545, ext. 7513 or bjudson@roofingindustryalliance.net.