Design Wind Speed and Warranty Wind Speed
July 10, 2019
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.
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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