Flashing Options for Every Detail
June 11, 2019
Carlisle offers three different types of Sure-Seal® Pressure-Sensitive (PS) flashings to address the variety of details found on any given roof. All three feature the proven weatherability of EPDM and come with 30-mil of Pressure-Sensitive (PS) SecurTape™ to create a watertight seal. The primary difference among the three is the amount of cure in the rubber, and the process used to manufacture them.

PS Elastoform – often called “uncured” flashing – is used to flash irregularly-shaped objects or details with multiple angle changes. The uncured state of the flashing allows the rubber to be formed and stretched into place without reverting to its original shape like cured rubber. The flashing formulation is designed to cure on the roof with exposure to heat. Since it is necessary to limit heat exposure in the manufacturing process; to keep the product uncured; Carlisle requires all edges to be lap sealed. This prevents water from getting between the flashing ply and the tape ply while the material cures on the roof. T-joints, corners, and pockets are all made from Elastoform flashing – which has a 9-month shelf life.

PS Overlayment Strip – often called “semi-cured” flashing – utilizes the same Elastoform flashing formulation, but is semi-cured with heat during the manufacturing process. The overlayment strip has the dark black look of uncured flashing, but is 70% cured in order to add tear resistance for stripping in metal edging or end laps. PS Overlayment Strip is packaged without the diamond pattern film, as it is removed during the semi-curing process. This is an easy way to tell the difference between PS Overlayment Strip and a roll of PS Elastoform. Due to the semi-cured nature of PS Overlayment strip, it can seal step-offs at splice intersections of 60-mil rubber without the need for T-joint covers. PS Overlayment Strip is better suited to strip-in seams than PS Elastoform, as it eliminates the need for lap sealant and T-joints.

PS Cured Cover Strip is made with the same 60-mil non-reinforced membrane as Carlisle’s standard sheeting, and then laminated to 30-mil of SecurTape. This product is primarily used for stripping-in metal or end-laps and offers the same finished appearance as the field membrane. Due to the fully-cured nature and thickness of the product, T-Joints are required at splice intersections.

Carlisle SynTec’s Sure-White® Pressure-Sensitive Flashing is available in Elastoform and cured cover strip options, and is approved for use on both EPDM and TPO roofing systems. Sure-White Elastoform has a more aggressive cure package to account for the fact that the white flashing will not gain as much heat naturally on the roof. This translates into a shorter shelf life of 6 months. Keeping white or black Elastoform flashing cool during long term storage will help to maximize the shelf life.

Carlisle SynTec has all your flashing needs covered. For more information about pressure-sensitive flashing, please contact your Regional Technical Manager.

    Ron Goodman
    EPDM Product Manager
    Product Marketing
    [email protected]
August 6, 2019
TPO and PVC Welding Guidelines

Cold welds are a major concern for any thermoplastic roofing installer. But following a few basic guidelines can go a long way toward ensuring good, long-lasting welds on TPO, PVC, and KEE HP membranes. In this post, we’ll discuss a few best practices that reduce the chances of cold welds and help ensure the watertight integrity of TPO, PVC, and KEE HP single-ply roof systems. 1. Appropriate Equipment Use proper power sources or commercial-grade generators. Generators should be rated for 3,000 watts for two hand welders, or 6,500 watts for one auto-welder. Proper extension cords are critical. For auto-welders, use a 10-gauge wire with a maximum length of 100 feet; for hand welders, use a 12-gauge wire with a maximum length of 100 feet. Welders should be in good shape, with clean air screens and a clean nozzle. 2. Proper Temperatures The following are starting guidelines for temperature, speed, and airflow. Settings may vary depending on membrane thickness (45-, 50-, 60-, or 80-mil). Leister Varimat Temp Speed Airflow TPO 1004°F 12.5 ft/min 100% PVC & KEE HP 1094°F 8.5 ft/min 100% ​ Leister V2   Temp  Speed Airflow TPO 986°F 18 ft/min 90% PVC & KEE HP 1094°F 10.4 ft/min 75% ​ BAK LarOn Temp Speed  Airflow  TPO 1004°F 12.5 ft/min 100% PVC & KEE HP 1094°F 8.5 ft/min 100% 3. Critical Welding Steps Keep in mind that ambient temperatures will affect welding temperatures and speeds, as will welding in the sun versus welding in the shade. Certain substrates can hold heat in the membrane (polyiso insulation), while others can rob the heat from the membrane (concrete). When hand welding, immediately roll across the hot seam at a 45° angle with a 2” silicone roller. This helps to ensure the top membrane is adequately pressed into the bottom membrane. When welding across a step-off, be sure to crease the top membrane into the step-off with a 2” silicone roller immediately after welding. This will help prevent a water channel from forming in the weld. It’s important to perform test welds several times each day because of changing ambient and membrane temperatures. Simply cut a 1”-wide strip across the weld and peel to inspect the weld area. Remember to probe all seams at the end of each work day. 4. Cleaning and Maintenance Always clean aged or dirty membrane before welding. On PVC or KEE HP, use PVC and KEE HP Membrane Cleaner; on TPO, use Weathered Membrane Cleaner. Clean all residue from the weld area and allow it to dry before welding. Maintain your equipment before, during, and after welding. Regularly inspect the silicone pressure wheels on your auto-welder and hand roller to make sure they’re not affecting the integrity of the membrane while welding or rolling. Clean the char off the heat gun nozzle using a brass wire brush and keep the intake free of debris to allow maximum airflow. On the auto-welder, adjust the nozzle to eliminate heel drag. Following these helpful hints will ensure a better installation with fewer cold welds. If you have questions, check out Carlisle’s TPO and PVC Welding Guides or contact your Field Service Representative. TPO Welding Guide PVC/KEE HP Welding Guide     John Greko     PVC Product Manager     Product Marketing     [email protected]

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July 23, 2019
Addressing Common Mistakes with Two-Component Low-Rise Adhesives

Two-component low-rise urethane adhesives have become increasingly popular since their introduction into the single-ply roofing industry over 30 years ago. Since 2015, the two-component low-rise urethane adhesive market has significantly expanded due to the introduction of new low-pressure dispensing equipment. While low-rise urethane adhesives provide several advantages when designing a roof to withstand extreme weather events, there are common mistakes that can affect the application of the product. Below are common mistakes that can occur during two-component urethane adhesive applications: Gaps between the deck and wall/penetration that are not sealed: Unsealed gaps allow humid air to enter the roofing assembly and condensate on the deck, weakening the insulation facer. A physical air block using foam or a backer rod in addition to VapAir 725TR or Pressure-Sensitive Flashing is required. Loose material or moisture on the deck: Dirt, dust, debris, and loose felts will compromise the adhesive bond. After brooming, use a blower to remove any residual contamination. Deck must be dry. Un-weathered asphalt wasn’t primed: Carlisle requires the use of CAV-GRIP™ III or 702 Primer over weathered asphalt when beads are spaced at 4”, 6", or 12" o.c.. Adhesion to un-weathered asphalt is doubled with CAV-GRIP III or 702 Primer, with CAV-GRIP III being the preferred method. Fastening the first layer of insulation is an option. Depressions in the deck not accounted for: Hard insulation boards will bridge depressions or deflections in the deck. These areas should be marked ahead of time so that more adhesive or thicker adhesive can be applied to compensate. Pencil thin beads applied: Proper application and performance requires a minimum ½"-wide wet bead of adhesive that will foam out to around 1-1.5". Bead spacing exceeds specification: Bead spacing has a direct impact on the uplift performance of the assembly. If the spec calls for 6" o.c. and it is applied it at 8" or 9" o.c., the ultimate uplift strength will be reduced. A 4" o.c. spacing requires 12 beads per 4' x 4' board. A 6" o.c. spacing requires 8 beads per 4' x 4' board. A 12" o.c. spacing requires 4 beads per 4' x 4' board (Maximum 4' x 4' insulation boards when adhesive is extruded at 12" o.c. or when boards exceed 4" thickness, or 4' x 8' insulation boards when adhesive is applied in full spray, 4", or 6" beads.). 12" bead spacing used in corners and perimeters: Corners and perimeters experience more wind uplift pressure, which is why Carlisle requires tighter bead spacing in these areas. 12" bead spacing is not acceptable in corners or perimeters. Know the spacing requirements prior to starting the job. Thin application over gravel BUR: A thicker application of adhesive is required over a properly prepared gravel BUR. The foam must rise 3/8" above the remaining gravel, or it won’t touch the board. Not waiting for “string/gel” time: If insulation boards are set prior to the adhesive reaching string- or gel-like consistency, the foam cells collapse back to a liquid and the adhesive loses a significant amount of its holding power. This is very important to note. No weighted roller used, and no relief cuts or constant weight applied: Rigid insulation boards must be forced into the adhesive with a 150-lb. segmented weighted roller. Relief cuts and constant weight are sometimes required to promote a solid bond. Rolling the boards at the 5-minute mark allows adhesive to gain strength. Changing static mixing tips: When the Part-A side and Part-B side of 2-component urethane adhesives are mixed together, it creates a thermal reaction that produces the adhesive. The adhesive in small static mixing tips will begin to solidify after 15-20 seconds, meaning the tips must be changed to avoid off-ratio or clogged guns. Not shaking Dual Tanks: Dual Tanks use a propellant to disperse the adhesive. To activate the propellant, the tanks must be shaken for 30-seconds prior to using. When the tanks are not agitated, the adhesive will not disperse properly, reducing coverage rates or producing off ratio adhesive. Cold or Hot Adhesive: Keeping adhesive at the recommended temperatures is important to ensure proper performance. Adhesives that are too cold or too hot will affect coverage rates and the performance of the adhesive. During winter applications, hot boxes and heated blankets should be used to keep the material between 70-90°F. For more information about two-component low-rise adhesives, please contact Austin Kulp.     Austin Kulp     Fleece Membranes & Coatings Product Manager     Product Marketing     [email protected]

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July 9, 2019
CAV-GRIP III Dos and Don'ts

CAV-GRIP™ III Low-VOC Adhesive is an optimal choice when you’re installing fully adhered EPDM or TPO roofing systems. This low-odor adhesive requires minimal setup time, dries fast, and can be applied quickly and accurately. Plus, its long “open time” makes it a prime candidate for projects utilizing larger sheets. Like anything else, there are dos and don’ts associated with using CAV-GRIP III. Check out these guidelines to ensure a proper, headache-free installation. DO Keep replacement tips handy – CAV-GRIP III spray guns have brass tips which achieve the optimal spray pattern. However, a clogged or damaged tip can negatively affect spray capabilities and result in wasted adhesive. To ensure that a damaged tip won’t delay your progress, it’s a good idea keep a bag of replacement tips handy. Use a splitter – Consider using a splitter if you’re working with the larger 85 lb. cylinders. Splitters allow you to attach two hoses to one tank, which can double productivity. Store properly – Store CAV-GRIP III cylinders in a protected, conditioned space with temperatures above 70°F prior to and during application. If CAV-GRIP is stored below the 70-degree mark, you’ll have to wait for it to warm up before application. If a cylinder is below the minimum temperature, it will produce an intermittent spray or “sputter” when it is used. TIP: try warming the product up before checking to see if your gun or hose are clogged. Secure all cylinders – Make sure you properly secure cylinders (regardless of whether they’re full, partially full, or empty) so they can’t roll off the roof. Use the right gun for the situation – The CAV-GRIP III Spray Gun with Extension Wand is perfect for wide-open roof areas, while the regular CAV-GRIP III Spray Gun (without the extension wand) is ideal for tight or confined areas. Keep the gun moving – Keep the spray gun moving while you’re spraying the adhesive to avoid thick or puddled areas. Adjust your technique if necessary – While you’re spraying, you may need to adjust the distance between the gun and the substrate to attain the proper coverage rate. In windy conditions, control the amount of trigger pull to ensure a proper web pattern is achieved and to prevent adhesive from being blown away. Clean up – You can reuse your guns and hoses over and over again if you keep them clean. First, completely depressurize the cylinder. Disconnect the gun and hose assembly and immediately attach it to a canister of Low-VOC UN-TACK™. Pull the trigger and allow the UN-TACK to flow through the hose and gun for five to ten seconds, or until the liquid coming out is clear. Depressurize the UN-TACK, remove the assembly, and store for future use. DON'T Don’t wipe adhesive off the spray tip – Immediately after spraying CAV-GRIP III, you may see adhesive buildup on the tip of the spray gun. The installer’s first reaction is often to wipe away this residue with a rag; however, doing this forces cured adhesive back into the tip orifice, leading to improper spray patterns and ultimately a clogged gun. Instead, allow the adhesive to thicken on the tip and peel away the buildup when you’re ready to spray again. Don’t shake – Unlike Carlisle’s Flexible FAST™ Dual Tank Adhesive, you do not need to shake the CAV-GRIP III cylinder prior to application. Shaking the cylinder will disrupt the adhesive and result in the loss of propellant, which is vital to achieving the expected 1,000 ft2 coverage rate per cylinder in a two-sided application. Don’t tilt – Don’t tilt the cylinder or lay it on its side while applying adhesive. Doing so will result in air pockets within the gun and hose assembly which could affect the spray pattern and reduce your coverage rate. Don’t mishandle – CAV-GRIP cylinders are pressured tanks and must be handled with care. Treat cylinders more like a propane torch set and less like a pail of standard bonding adhesive, both on and off the jobsite. Don’t overspray – Don’t apply adhesive to splices to be hot-air welded or areas where primer and pressure-sensitive tape will be applied. If overspray occurs, use Weathered Membrane Cleaner or commercial-grade duct tape to remove it. Don’t install membrane too soon – Don’t install membrane over wet or puddled CAV-GRIP III. Doing so will trap solvents between the membrane and substrate, causing “solvent bubbles”. Allow the adhesive about three to five minutes to set up, or become tacky, before installing membrane. Don’t use band heaters in cold weather – Band heaters can reach temperatures of more than 400° F, which can cause over-pressurization inside the cylinder and lead to a valve failure and loss of product. Instead, try power-heated blankets and/or hot boxes when necessary. Don’t let a disconnected hose sit around – Adhesive can cure inside the hose or gun, causing it to sputter or become blocked. When switching a hose and gun assembly from one cylinder to another, make sure both cylinders are sitting side-by-side during the change. Shut the empty tank off, point the wand into a trash bag, and pull the trigger to empty all excess adhesive out of the hose and gun. Then, unhook the hose from the empty tank and immediately hook it up to a new cylinder. Don’t punch a hole through the side of the tank when the tank is under pressure – Once the hose is removed, open the tank back up slightly to relieve excess pressure. From there, punch a hole through the designated area and properly dispose of the tank. Additional Resources Request Free Trials  CAV GRIP III Low-VOC Adhesive/Primer Product Data Sheet  CAV GRIP III Low-VOC Adhesive/Primer Accessories Product Data Sheet CAV GRIP III Application Video CAV-GRIP III Time Trial Video For technical assistance, or for more information on CAV-GRIP III, please contact Ryan Ferguson.     Ryan Ferguson     EPDM Product Specialist     Product Marketing     [email protected]

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