October 16, 2019

Electronic Leak Detection for Roofing Systems

A building’s roofing system separates the damaging outdoor environment from the valuable interior contents. To be effective, it must be watertight. Although roof systems are inspected and sometimes flood tested prior to warranty issuance, small, difficult-to-see breaches in the membrane system can go unnoticed until damaging water leaks occur inside the building. Moreover, once a leak has developed it can be extremely difficult to locate the leak and perform the necessary repair, especially when overburden materials are installed. Enter Electronic Leak Detection, otherwise known as ELD. ELD systems have been around for 20+ years and are gaining popularity due to some revolutionary new products that have expanded testing capabilities. ELD systems come in two main varieties: low-voltage and high-voltage, with low-voltage being the most common. ELD systems work by creating an electrical potential difference between a non-conductive roof membrane and a grounded conductive structural deck or substrate. Testing is performed by applying water, which is conductive, to the surface of the roof membrane. The roof membrane will isolate the potential electrical difference between the deck and the water, but when a breach is present, the water will create an electrical connection to the grounded deck, pinpointing the exact leak location to the testing technician. A major benefit of ELD testing is that it can be performed at any time, even after overburden materials are installed. For ELD systems to be effective, a conductive substrate must be present directly below the membrane’s surface. Due to this requirement, membrane choice and application method can be limited. Two ELD companies that Carlisle has experience with are International Leak Detection (ILD) and Detec Systems. Products from either of these companies are permitted for use in a Carlisle warranted roof system but are not covered in the Carlisle warranty. ILD has been around since 2001 and promotes a conductive mesh that must be installed directly below the membrane for accurate testing of membrane systems over non-conductive decks. Due to the design of the conductive mesh, it is only acceptable for use under thermoplastic FleeceBACK® membranes adhered with FAST™ or Flexible FAST Adhesive. Detec Systems promotes a conductive primer called TruGround® that is roller-applied over the top layer of insulation, prior to adhesive application. Once dried, the membrane system can be installed as usual. TruGround conductive primer expands ELD testing capabilities, as it is suitable for use with bareback membranes and even black EPDM, which historically has not been compatible with ELD testing. Carlisle SynTec Systems has secured FM approvals for Detec’s TruGround in a number of different roofing assemblies. Those assemblies include: EPDM and TPO with CAV-GRIP® III adhesive over SecurShield®, SecurShield HD, DensDeck® Prime, and SECUROCK®. PVC with Low-VOC Bonding Adhesive over InsulBase®, SecurShield, SecurShield HD, and SecurShield HD Plus.  Contact Chris Kann with questions regarding ELD systems.

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September 18, 2019

Fire Performance of Polyiso

All construction materials, including foam plastics such as polyiso insulation, must provide a suitable margin of fire safety. Polyiso possesses a high level of inherent fire resistance when compared to other foam plastic insulations due to its unique structure of strong isocyanurate chemical bonds. These bonds result in improved high-temperature resistance (up to 390°F [199°C], more than twice that of other building insulation foams) which in turn leads to enhanced fire resistance. In addition, because polyiso does not melt or drip when exposed to flame, but rather forms a protective surface char, its fire resistance is further enhanced, especially in terms of flame spread and flashover potential. Polyiso passes both the ANSI UL 1256 and FM 4450 fire tests without a thermal barrier. Polyiso, a thermoset material, stays intact during fire exposure in the ASTM E84 or "Tunnel Test.” It forms a protective char layer and remains in place during the test, thereby meeting all building code requirements and contributing to a fire-safe building. For more information on polyiso’s performance in fire tests, visit the 'Technical Bulletins’ page on the PIMA (Polyiso Manufacturers Association) Website where you can find the following papers: Technical Bulletin 103: Fire Performance in Walls and Ceilings Discusses polyiso insulation as it relates to building codes in construction and fire tests in walls and ceilings, including ASTM E84 and ASTM E119. Technical Bulletin 104: Fire Performance in Roof Systems Provides an overview of polyiso insulation requirements for roof systems and key issues in fire performance, including the importance of the FM 4450 Calorimeter Tests and the UL 1256 Resistance to Interior Spread of Flame test. Technical Bulletin 105: Fire Test Definitions Provides an in-depth look at fire test procedures for building applications. Technical Bulletin 111: Class A and Class 1 Roof Assemblies Are Not the Same Explains why Class 1 and Class A are not the same. Technical Bulletin 111C: Roofing Regulations in Canada – Class A and Class 1 Roof Assemblies Are Not the Same Explains why Class 1 and Class A are not the same. Technical Bulletin 405: Fire Resistance Properties of Polyiso Foam Plastic Insulation Used in Wall Assemblies – Facts and Comparisons Looks at the minimum fire resistance properties required for foam plastic insulation and compares data on polyiso with other recognized combustible materials. Product Stewardship Paper 100: Polyiso Insulation and Flame Retardants New Product Stewardship report on polyiso and flame retardants. Contact Craig Tyler at [email protected] with questions.

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September 4, 2019

Alternative Uses for Roofing Membranes

All single-ply membranes make for great roofing systems, but they can be used for a variety of other purposes too. EPDM, TPO, and PVC can be used in the lining of underground tunnels and can serve as liners for water retention ponds, irrigation canals, and other water containment systems. For years, EPDM membranes were used as pond liners – even before they were utilized for commercial roofing. You could see EPDM pond liners being used in agriculture for irrigation canals and ditches, by municipal water systems for retention ponds and spillways, and even in backyards as small ponds and water features. This is still true today, and EPDM has expanded into additional markets such as tunnel waterproofing. The number of large underground transportation tunnels used for vehicle traffic or metropolitan railways has certainly increased in the last few decades as traffic and access needs continue to outstrip the supply of existing infrastructure. These tunnels have to keep water out, whether they’re underneath a river or traversing through a mountain, and single-ply membranes meet their waterproofing needs with the same technology used on the roof. Different types of membrane offer specific benefits, from EPDM’s large sheet size to thermoplastics’ (TPO/PVC) seam weldability. Regardless of whether the tunnel is a boring project or a “cut and cover”, lining the tunnel can be accomplished using several different installation methods and can utilize EPDM, TPO, or PVC. For more information, please consult the links for the products or specifications on the Carlisle SynTec website below. Tunnels – Conventional Blindside Method Consult the Tunnel Waterproofing System – Conventional Specification and Details on the Carlisle SynTec website.  Tunnels – Cut and Cover Method Consult the Tunnel Waterproofing System – Cut and Cover Specification and Details on the Carlisle SynTec website.  Pond Liners Consult GeoMembrane Page for Pond Liner Products and Brochures on the Carlisle SynTec website.   Contact Craig Tyler at [email protected] with questions.

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August 21, 2019

Understanding FM 1-52

There are two recognized field test methods for determining uplift resistance of adhered membrane roof systems, both of which can be problematic: ASTM E907, "Standard Test Method for Field Testing Uplift Resistance of Adhered Membrane Roofing Systems," and  FM Global Loss Prevention Data Sheet 1-52 (FM 1-52), "Field Verification of Roof Wind Uplift Resistance."  Both test methods provide for affixing a 5’ x 5’ dome-like chamber to the roof’s surface and applying a defined negative (uplift) pressure inside the chamber to the roof system's exterior-side surface using a vacuum pump, like in the photo below.  An example of a test chamber used for negative-pressure uplift testing However, ASTM E907 and FM 1-52 differ notably in their test cycles and maximum test pressures for determining roof system deflections and whether a roof system passes or is “suspect”. Using ASTM E907, a roof system is “suspect” if the deflection measured during the test is 25 mm (about 1 inch) or greater.  Using FM 1-52, a roof system is “suspect” if the measured deflection is between ¼ of an inch and 15/16 of an inch, depending on the maximum test pressure; 1 inch where a thin cover board is used; or 2 inches where a thin cover board or flexible, mechanically attached insulation is used.  Test results' reliability  The reliability of the results derived from ASTM E907 and FM 1-52 is a concern, especially when the tests are used for quality assurance purposes. A note in ASTM E907 acknowledges its test viability. "Deflection due to negative pressure will potentially vary at different locations because of varying stiffness of the roof system assembly. Stiffness of a roof system assembly, including the deck, is influenced by the location of mechanical fasteners, thickness of insulation, stiffness of deck, and by the type, proximity, and rigidity of connections between the deck and framing system." For example, when testing an adhered roof system over a steel roof deck, placement of the test chamber relative to the deck supports (bar joists) can have a significant effect on the test results. If positioned between deck supports, the test chamber's deflection gauge will measure roof assembly deflection at the deck's midspan, which is the point of maximum deck deflection. Also, in many instances, field-uplift testing results in steel roof deck overstress and deck deflections far in excess of design values, which can result in roof system failure. These situations can result in false “suspect” determinations of a roof system. Industry position/recommendations Because of the known variability in test results using ASTM E907 and FM 1-52 and the lack of correlation between laboratory uplift-resistance testing and field-uplift testing, the roofing industry considers field-uplift testing to be inappropriate for use as a post-installation quality-assurance measure for membrane roof systems. Conclusion FM 1-52 is an FM Global-promulgated evaluation method and not a recognized industry-consensus test standard. The scope of FM 1-52 indicates that it’s only intended to confirm acceptable wind-uplift resistance on completed roof systems in hurricane-prone regions, where a partial blow-off has occurred, or where inferior roof system construction is suspected or known to be present. FM 1-52 was originally published by FM Global in October 1970. The negative-pressure uplift test was added in August 1980 and has been revised several times. The current edition is dated July 2012 and includes an option for "visual construction observation (VCO)" as an alternative to negative-pressure uplift testing. VCO provides for full-time, third-party monitoring to verify roof system installation is in accordance with contract documents. For more information, contact Craig Tyler.

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August 7, 2019

LEED, Green Globes, and Living Building Challenge

For years, “going green” initiatives have been popping up in all aspects of our lives. In the construction industry, there are three main programs pushing buildings to be greener: LEED®, Green Globes, and Living Building Challenge (LBC). All three of these programs push for more sustainable buildings, but each takes a different approach to accomplish this goal. In this SpecTopics post, we will look at some of the differences between these three programs. Put simply, LEED and Green Globes are working toward making buildings more sustainable by improving existing standards, while LBC takes things a step further and promotes buildings that have little to no negative impact on the environment.  Overall Mission LEED wants to make buildings better for the environment, community, and those who use the building Green Globes wants to make buildings more environmentally efficient based on commonly valued environmental outcomes LBC promotes buildings that have a positive environmental impact   Certification Methods/Requirements  LEED  Points-based rating system (100 points possible)  Four levels of certification: Certified, Silver, Gold, and Platinum Green Globes  Points-based rating system (1,000 points possible)  Four levels of certification: 1 Globe, 2 Globes, 3 Globes, 4 Globes LBC  Seven petals (like those of a plant or flower) broken down into 20 imperatives; number of petals/imperatives completed determines award  Three awards are available (based on which path you take)  A Zero Carbon Certification and a Zero Energy Certification are available Main Points of Focus  LEED Location & Transportation, Sustainable Sites, Water Efficiency, Energy & Atmosphere, Material & Resources, Indoor Environmental Quality, Innovation, Regional Priority, and Integrative Process Green Globes Project Management, Site Energy, Water, Materials & Resources, Emissions, Indoor Environment LBC Place, Water, Energy, Health & Happiness, Materials, Equity, and Beauty

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July 24, 2019

Solar Ready Roofing

As designers and architects try to meet green construction or net-zero energy goals, on-site power generation in the form of photovoltaic (PV) arrays is becoming more and more common. Preparing your roof to accept a PV system in the future is also increasingly commonplace. In general, robust roofs with extended warranties are the best candidates for PV systems. While a normal roof may only experience light foot traffic from the building owner or maintenance personnel a few times a year, a PV installation may need more frequent inspections (i.e. after significant storms or heavy snowfall, monitoring, etc.). So starting out with a thicker membrane, a cover board, and walkway pads are a must. It’s important that the PV array does not interfere with the roof’s drainage. This may mean some of the array will have to be supported by structural steel tubing or piping in lieu of traditional racking (which may rest on the roof utilizing ballast). It’s important to leave room for roofers to inspect or repair seams and flashings, so it may be necessary to raise the height of the array as not to obstruct roof penetrations. Always verify the type of PV array system to be installed on your roof and coordinate with your local Carlisle Field Service Representative (FSR) to assess the new or existing roof’s condition prior to beginning any work. Consult the SOLAReady Specification on the Carlisle SynTec website at or contact Craig Tyler with questions.

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July 10, 2019

Design Wind Speed and Warranty Wind Speed

We’ve already discussed wind uplift design in a previous SpecTopics post (FM 1-90 vs. ASCE 7); this post will help you understand how those wind speed numbers relate to wind speed warranties.  To calculate wind uplift for a roofing project, you’ll need to determine the building type and local wind speed. In gathering this information, some designers look at the American Society of Civil Engineers’ ASCE 7 Wind Maps for their area, see a number like 90- or 120-mph, and think that is the wind speed their building will encounter. Therefore, they specify the same speed for their warranty (i.e. 120 mph local speed means I need a 120-mph wind speed warranty). Rest assured, this is not the case. ASCE 7 maps have contours with the local speeds in 10 mph increments. ASCE 7-2005 and ASCE 7-2010 were relatively straightforward; most of the U.S. was in a 90-mph zone. However, in 2016 ASCE deemed it necessary to have separate maps for each building risk category (Category I, II, III, and IV). This increased the wind speeds for most of the country, especially for projects with increased risk categories. Naturally, designers saw this increase and thought that since the local wind speed was increasing, they needed to ask for increased wind speed warranties. (i.e. 130 mph or more). Again, this is not the case. It’s true that warranted wind speed is the limit of 3-second peak gust recorded at the weather station nearest your building project, measured at 10 meters above the ground, during a weather event that affects your building project. But to achieve wind speeds over 90 mph, a cyclonic windstorm (tornado, hurricane, etc.) is generally necessary. If your building experiences a cyclonic windstorm, there will be flying debris, broken glazing, and other envelope breaches that could cause roof failure (over-pressurizing the building, detachment of decking from structural components, etc.). This would not be covered under a roofing warranty, regardless of the wind speed coverage. Keep in mind that a roofing warranty assumes that the building remains intact, the decking remains solid, the inside pressure of the building is generally equalized, and foot traffic is limited to maintenance and inspection of rooftop equipment. It is not building insurance. Like fires and vandalism, critical weather events such as tornadoes and hurricanes are covered by the building owner’s insurance carrier. Choose a warranted wind speed that makes sense for you and your client, but you don’t need to match that with your local wind speed. You’ll just be paying more for something you don’t need. Always verify your need for increased warranty wind speed before inquiring about matching your local wind speed with the warranty. Contact Craig Tyler at [email protected] with questions.

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June 26, 2019

Moisture in Concrete - Part 1

This post focuses on the moisture phenomenon in concrete and the difference between lightweight and normal-weight structural concrete. Curing versus drying and the standards used to determine relative humidity levels are also addressed. Part II will address design recommendations and roof assembly selection. Moisture in Newly Poured Structural Concrete Roof Decks When investigating roofs for leaks, invariably, moisture is found beneath the roof membrane. However, the source of moisture is not always a roof leak. Newly poured structural concrete could be a contributor to the presence of moisture beneath a new or a replacement roof. Concrete is a mixture of several components that reaches its optimum strength through a chemical reaction induced by water. Concrete needs water to allow for flowability and workability, however, water also has adverse effects. Once the concrete has cured, the remaining water is considered “free water”, or moisture which is no longer consumed by the curing process. Rain and snow add moisture to exposed concrete roof decks and further prolong the drying. As an example, a 4” slab of structural concrete contains as much as 200 gallons of free water per 1,000 square feet. ​Structural Concrete Mix Ratio The ratio for both normal-weight and lightweight structural concrete (LWSC) is generally the same: •10-15% cement •60-75% aggregate (fine and coarse) •15-20% water The difference is in the aggregate; the lightweight aggregate is pre-saturated prior to mixing. The lightweight aggregate, which is made up of shale, slate slag, or clay, can absorb 5-25% of its mass. Normal-weight structural concrete, however, utilizes aggregates such as sand and stone, which are not as porous and do not need to be wetted before adding to the mix. The popularity of LWSC is increasing due to: •Lower building structural cost; •Lesser density for reduced dead loads; and •Environmental and sustainability claims. Drying Time To reach a 75% relative humidity for normal-weight structural concrete, it will take approximately three months. However, achieving the same 75% relative humidity for LWSC will take twice as long. According to the Portland Cement Association, the dry-down time for LWSC is more than normal-weight structural concrete. Standards for Moisture Testing For many years, the roofing industry has used a curing time of 28 days after the concrete is poured. However, there are test methods published by ASTM for determining the moisture content in concrete. Qualitative tests, such as the plastic sheet test and electrical resistance and/or impedance are good indicators of the presence of moisture in a given area but are not as accurate as quantitative tests. Quantitative tests, such as the moisture vapor emission rate test, surface humidity, or in-situ relative humidity tests demonstrate levels of moisture present in the concrete. The recommended quantitative test is the in-situ relative humidity test (ASTM F2170), in which a sleeved probe is placed in a drilled hole in the concrete and left in place for 24 hours. After the 24 hours, an electronic reader is attached, and the information is read directly from the sensor. The relative humidity reading should be less than 80% at a depth of approximately 40% of the thickness of the slab. The moisture values and test duration stated above have been slightly modified to better suit outdoor roof conditions.  Site Considerations The concrete pour schedule can affect moisture testing and provide inaccurate moisture values. Therefore, in phased construction, the field testing and the roofing installation should be aligned with the concrete pour schedule and ICRI-Certified Concrete Inspectors should be commissioned. For in-depth information, the International Concrete Repair Institute (ICRI) offers various resources that can aid with the proper steps required for testing and evaluation. Stay tuned for part II for recommendations on design and the selection of an appropriate roofing assembly.

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June 12, 2019

An Alternative to Metal Roofing: Special Color TPO with Contour Ribs

An Alternative to Metal Roofing: Special Color TPO with Contour Ribs Carlisle’s TPO Contour Rib Profile offers the look of a standing seam metal roof with the performance of a TPO single-ply membrane. Each section of Contour Rib Profile is manufactured from the same weather-resistant compound as TPO membrane and enhanced with fiberglass for added dimensional stability. The product’s rectangular shape provides exceptional shadow lines for aesthetic appeal.  TPO Contour Rib Profile Quick Facts  Available colors: White, Gray, Tan, Terra Cotta, Patina Green, Slate Gray, Rock Brown, and Medium Bronze. Size: Each section is 1 1/4" tall, 2 1/8" wide (including welding flanges), and 10’ long; the vertical profile is 3/8" thick with a 1/8" alignment hole and a 1/8" fiberglass reinforcing cord. Packaging: 20 pieces per carton, each carton includes 25 connecting pins. Special-Color TPO Program Quick Facts - Carlisle has the industry’s most comprehensive special-color TPO program, with membranes and accessories in Medium Bronze, Patina Green, Rock Brown, Terra Cotta, and Slate Gray. - There are no minimum order quantities. - The following TPO products are available in the five special colors. 1. 60-mil standard reinforced TPO membrane – 5’ x 100’ and 10’ x 100’ rolls.  • 10’ x 100’ rolls – limited quantities stocked in Mississippi; large orders may require a one- to    two-week lead time.  • 5’ x 100’ rolls – require a short lead time; customers must order an even number of rolls.  2. 24” Non-Reinforced TPO Flashing – limited quantities stocked in Mississippi; large orders may require a one- to two-week lead time. 3. TPO Contour Rib Profile – limited quantities stocked in Mississippi; large orders may require a one- to two-week lead time. 4. TPO Coated Metal – made to order; requires a one- to two-week lead time. 5. 115-mil 12’ x 100’ FleeceBACK® TPO – manufactured at the beginning of each calendar quarter (January, April, July, October) to fulfill all orders that are in-hand by the 15th of the previous month (March 15, June 15, September 15, December 15). You can combine Contour Ribs with special-color TPO to create a simulated metal roof in Medium Bronze, Patina Green, Rock Brown, Terra Cotta, or Slate Gray.  Contact Craig Tyler at [email protected] with questions.

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May 29, 2019

Building Envelope Educational Courses, Tools, and Materials

The demand for high-performance building envelope systems is on the rise. Energy codes such as ASHRAE 90.1 and the IECC continue to increase requirements aimed at creating more energy efficient and environmentally friendly designs. Some of these increasing code requirements involve the addition of continuous air barriers, as well as continuous insulation to wrap the entire building. Architects, specification writers, and designers have the almost impossible task of staying up-to-date on new code requirements, understanding how and why changes were made, and accurately and appropriately incorporating these changes into their designs. Over the last several decades, Carlisle Construction Materials (CCM) has become the premier single-source supplier of building envelope materials, including single-ply roofing, air and vapor barriers, waterproofing membranes, insulation, metal products, and more. Therefore, CCM is focused on educating and assisting design professionals through training courses, as well as helpful tools and materials, to minimize the learning curve experienced by architects when code changes occur. Here’s some information on CCM’s newest educational courses, tools, and materials to help you stay at the forefront of building envelope designs. Education is paramount to the success of building envelope projects, which is why CCM offers free courses to design professionals on various building envelope design considerations. CCM’s “Pushing the Envelope: Going Beyond Conceptual Design” is a 300-level, AIA-accredited course that explores proper product selection, material performance characteristics, test procedures, and best practices as they relate to building envelope systems. It is available online as a self-guided course here or you can request a face-to-face presentation here. CCM’s newest course, “Building Envelope Design – Understanding Codes, Best Practices, and Tie-in Detailing”, is a 400-level, AIA-accredited course available exclusively as a face-to-face presentation. This course helps raise awareness of code requirements as they relate to building envelope components and systems, with a focus on the all-important tie-in detailing needed to provide an air tight building. Common material misconceptions are also discussed. For more information on CCM’s Building Envelope Design course, or to request an face-to-face presentation, click here.  As energy code requirements increase the need for air barriers and continuous insulation, questions about fire safety may arise. In most cases, the International Building Code (IBC) requires compliance with NFPA 285, which is the Standard Test Method for Evaluation of Fire Propagation Characteristics of Exterior Wall Assemblies Containing Combustible Components. Carlisle Coatings and Waterproofing (CCW) offers both an online tool and mobile app that allow you to build an NFPA 285-approved assembly. When finished, a submittal document is created for the wall you designed, and this document can be provided to your building code official if your design is ever called into question. To build your NFPA 285 wall assembly, click here or download the app by searching “NFPA Guide” on the AppStore, GooglePlay, and Amazon. Since continuous air barriers became a requirement of energy codes, building designers have been given the difficult task of determining material compatibility and proper tie-in sequencing of dissimilar systems. CCM’s breadth of building envelope materials allows for the internal vetting of material compatibility, taking away the guesswork typically required from designers. CCM’s NVELOP details are easy to read and understand, illustrating the most common material combinations along with step-by-step installation instructions to create the continuous air seal required by energy codes. NVELOP details can be downloaded from the NVELOP website here. CCM is unique in its ability to provide a wide range of materials from a single source. Similarly, NVELOP is unique in its ability to provide a single-source warranty for the tie-ins between dissimilar CCM systems. However, the uniqueness of CCM and NVELOP can make specifying for public bid projects complicated. To address these difficulties, CCM developed the MasterFormat Specification Sell Sheet with instructions on how to write CCM and NVELOP as the basis of design in public bid project specifications, while keeping them open for competition. To download CCM’s NVELOP MasterFormat Specification Sell Sheet, click here. NVELOP is unique in its ability to provide warranty coverage for tie-ins between dissimilar CCM materials. Traditionally, applying for and receiving a warranty for tie-ins was either impossible or extremely difficult and involved lots of paperwork and time. NVELOP eliminates these issues with an easy online warranty application process. Once the individual CCM system warranties are purchased and received, visit NVELOP’s warranty application portal here and fill in the appropriate information. If you have questions about any of these building envelope tools, please contact Chris Kann at [email protected]

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May 15, 2019

FM 1-90 vs. ASCE 7

Wind uplift design for roofing can seem daunting to the uninitiated. But with a little help from online tools, it can be much more straightforward. Wind uplift is calculated for all buildings using formulas, tables, and wind maps developed by the American Society of Civil Engineers (ASCE) in their publication ASCE 7-2016. With a project’s location, building use/occupancy, building height, and roof plan, there are a number of online tools you can use to determine the wind uplift required for your building. The calculator used by the National Roofing Contractors Association (NRCA) can be found at http://www.roofwinddesigner.com/. Once the uplift pressures for your building are determined, you must choose a design for your building that meets these pressures. Roofing manufacturers list their system designs through the DORA Directory of Roof Assemblies https://www.dora-directory.com/ or through Factory Mutual Global’s RoofNav® https://www.roofnav.com/Account/Login. The DORA Directory lists roofing assemblies based on uplift testing that various manufacturers have received through third-party verification, while FM’s RoofNav lists roofing assemblies that have been tested through FM Global’s own testing facility. Roofing assemblies that meet the minimum uplift requirements per ASCE 7-16 will meet the International Building Code (IBC); however, FM Global ratings may require additional enhancements based on their own calculations. The more stringent guidelines are due to the fact that FM Global is an insurance company and they approve designs before they issue coverage for a particular building. While FM 1-90 is a rating used by FM Global-insured buildings as a standard for their insurance coverage, the calculation of wind load for a particular building using ASCE 7 calculations is the basis for designing a roof meeting the IBC for all buildings, whether or not they are insured by FM Global. Meeting the standard for FM 1-90 will result in higher pressures in the perimeter and corners than using the ASCE 7 method, thereby increasing the cost of the construction of the roof. Changing these requirements at a later date or finding out your project does not require FM ratings may cause confusion during the bidding process and could result in higher bids. Always verify your need for FM Global before proceeding with wind load design. Contact Craig Tyler at [email protected] with questions.

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May 1, 2019

Misconceptions About Permeance in Wall Air Barriers

In moderate climate regions, and especially in southern states, specifiers are often tasked with selecting an air barrier that is vapor permeable. In many cases, they are advised by product manufacturers’ reps that products with a higher perm rating will deliver better performance. Various manufacturers have used this tactic to drive the sale of their products and limit competition. To counter this misleading marketing technique, it is imperative to understand permeance, how it relates to vapor retarder classification, and what it all means in terms of building performance.  Permeance indicates the rate of water vapor transmission through a material and is dependent on the material’s thickness, much like R-value in heat transmission. Permeance is often abbreviated to “perm”, which is the unit of measure used for vapor retarder classifications. A material’s perm rating is also what is needed when comparing the water vapor transmission of different building products.  The table below shows vapor retarder classification as accepted by the International Building Code (IBC). It is important to note that the less permeable a material is, the greater its resistance to water vapor transmission. Classification Definition Permeance I Vapor Impermeable Greater than or equal to 0.1 perm II Vapor Semi-Impermeable Greater than 0.1 perm but less than or equal to 1.0 perm III Vapor Semi-Permeable Greater than 1.0 perm but less than or equal to 10 perms Vapor Permeable Greater than 10 perms As the table above illustrates, any material with a perm rating greater than 10 is classified as PERMEABLE. Selecting a product solely because it has a higher perm rating than the definition of permeable doesn’t add any meaningful benefits to the performance of the system. The most important thing to consider when comparing perm ratings of various products is the test in which the perm rating was determined. ASTM E96 is the Standard Test Method for Water Vapor Transmission of Materials. ASTM E96 contains two test methods to determine the perm rating of materials: Method A (the desiccant method) and Method B (the water method). Results from these two test methods vary considerably and cannot be compared in any way. Therefore, it is extremely important when comparing and choosing a vapor permeable or vapor impermeable air barrier that the results are from the same ASTM E96 test method. Method B is the most commonly used for classifying materials due to the higher results it yields, representing a worst-case situation with an excess presence of moisture. Please contact Chris Kann at [email protected] with questions.

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April 17, 2019

Do Building Codes Require Structural Enhancement for Re-roofing Work?

Today’s re-roofing market is going strong, making up 62% of all roofing work versus 38% for new construction. While most specifiers and roofers know the requirements for re-roofing to meet current building and energy codes, there is always a level of uncertainty when it comes to the structure of the roof itself. Can I tear off the old roof and start my new roof application with the existing deck? Or is something more required? Re-roofing work consisting of a complete tear-off is considered an Alteration – Level 1 for the International Existing Building Code (IEBC) 2015 and 2018 editions. In Chapter 5, an Alteration – Level 1 is described as, “includes the removal and replacement or the covering of existing materials, elements, equipment, or fixtures using new materials, elements, equipment, or fixtures that serve the same purpose”. Descriptions of the code requirements for Alteration – Level 1 are in Chapter 7 and include Section 707 – Structural, which describes two additional structural requirements for roof replacement: 1.(707.3.1) Where the re-roofing work is more than 25% of the roof area, and the building is assigned a seismic design category of D, E, or F (Chapter 20 of ASCE 7), unreinforced masonry wall parapets must be braced according to 301.1.4.2 of the International Building Code (IBC). 2.(707.3.2) If the existing roofing system is removed and the deck is exposed for more than 50% of the roof area and the building is located where the ultimate design wind speed is greater than 115 mph OR the project is located in a special wind region, all structural roof connections must be evaluated for the wind uplift, and if unable to support 75% of the wind load, they must be strengthened or replaced as defined in Chapter 16 of the IBC. These requirements will not affect all buildings. Checking with a structural engineer to determine the existing building’s seismic design category or evaluating wind uplift potential of existing structural components will increase the project’s cost. Additionally, more costs could be added if structural remediation is required. Always check with the Authority Having Jurisdiction (AHJ) for local requirements before proceeding with re-roofing work. Contact Craig Tyler at [email protected] with questions.

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April 3, 2019

A New Trend in Building Envelope Specifications

With the ever-increasing emphasis on airtightness in commercial buildings, many of today’s building envelope projects are taking an approach similar to that of the roofing industry, where products are sourced from and warranted by a single company. Traditionally, building envelope projects have used products supplied by multiple manufacturers for use in below-grade waterproofing, walls, and roofing systems. This poses several concerns for architects and designers, including product compatibility, system performance, and liability. Similar concerns are what led the roofing industry to shift to a single-source, “system” approach in the late 1980s. Today, most roofing systems are single source. These systems utilize materials designed to work together from the start, allowing suppliers to offer extended and unique warranty coverage and eliminate finger-pointing in the event of a leak. One of the biggest advantages of a single-source building envelope is the ability to avoid product incompatibility at tie-in junctions, which can lead to air barrier breaches. With its NVELOP Building Envelope Solutions program and wide breadth of manufacturing capabilities, Carlisle Construction Materials (CCM) is leading the way in the movement toward single-source building envelope systems. CCM’s NVELOP is the industry’s most comprehensive single-source building envelope solution, featuring a variety of waterproofing, wall, and roof system materials. NVELOP's ability to ensure the compatibility of dissimilar materials eliminates the guesswork architects have conventionally dealt with when designing a building envelope system, while still allowing for design flexibility. The program’s tie-in detail suite provides vetted tie-in options that have been tested for durability, compatibility, and constructability. Additionally, NVELOP’s unique single-source tie-in warranty, available for up to 15 years, significantly limits architect and specifier liability and provides peace of mind to the building owner. For more information, visit the NVELOP website at www.carlislenvelop.com. If you have questions, please contact Chris Kann at [email protected]

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March 20, 2019

Tectum Inc. Voluntarily De-Listed from the FM RoofNav Website

Carlisle Construction Materials (CCM) has learned that Tectum Inc. has voluntarily de-listed their decking products from the FM RoofNav site. Tectum Inc. produces structural acoustical roof decks made of wood fiber cement which absorb sound and are compatible with a wide variety of insulation and roofing materials. CCM’s roofing systems are compatible with Tectum decks and share many RoofNav-approved assemblies. Because of the de-listing by Tectum, the FM Approvals for wood fiber cement decks and all related RoofNav listings have been removed from the FM approval site for all roofing manufacturers, not just CCM. Consequently, all wood fiber cement deck ratings listed in Carlisle’s State of Florida Evaluation Reports have been added to the SPRI DORA (Directory of Roof Assemblies) listing website. These ratings will still be applicable and can be specified when using the SPRI DORA directory in lieu of specifying FM approved roof assemblies. Many specifiers use FM approval ratings as a general guide for design, but may be specifying them on buildings which are not insured by FM Global. When specifying for building projects that are not FM insured, the specifier may use SPRI DORA assemblies or UL assemblies. The SPRI DORA listing is a web application database of roof systems tested in accordance with standards referenced in Chapter 15 of the International Building Code (IBC). This service lists wind uplift load capacity on single-ply and modified bitumen roof systems. For more information on the listing, visit www.dora-directory.com or contact Brian Emert.     Brian Emert     Designer & Doc Dev Specialist     Design Services     [email protected]

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March 6, 2019

Welcome to SpecTopics!

Welcome to the first installment of SpecTopics, a bi-monthly blog about topics related to designing and specifying roofing and waterproofing systems using Carlisle’s products. Carlisle has been a recognized leader in the roofing industry for more than half a century, manufacturing high-performance EPDM, TPO, and PVC single-ply membranes. Carlisle also offers roof garden systems, a full line of polyiso and expanded polystyrene insulation, and a host of steep slope underlayments, duct sealants, adhesives, and hardware. In addition to roofing, Carlisle services the waterproofing, framing, and general construction industries. This blog-based format will allow us to answer the most frequently asked questions we receive from architects and specifiers, as well as to share technical information and industry news. Our goal is for SpecTopics to serve as a resource for roofing, waterproofing, and building envelope issues. The focus will be on industry-wide issues that affect building product specifications and code approvals for roofing and air and vapor barriers. In the next few installments, we’ll cover trends in building envelope specifications, FM 1-90 requirements versus ASCE 7 requirements, and code-related language regarding re-roofing. Stay tuned; another SpecTopic will be published in two weeks. Contact Brian Emert for further information.     Brian Emert     Designer & Doc Dev Specialist     Design Services     [email protected]

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