TPO and PVC Welding Guidelines
August 6, 2019
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]
                                                                                                                                                               
October 1, 2019
Special Color TPO Accessories

As the demand for different colored roof membranes has grown, Carlisle introduced its TPO Color Palette with five new colors. In addition to standard white, gray, and tan, Carlisle’s TPO Color Palette now features Rock Brown, Slate Gray, Terra Cotta, Patina Green, and Medium Bronze. Projects that use special color membrane from the TPO Color Palette usually need flashings and accessories in the same color. Here, contractors have two choices, one of which is painting standard accessories to match the membrane. However, this is a great opportunity to use Carlisle’s custom TPO accessory program and avoid painting altogether. All Carlisle custom accessories are available in the five TPO Color Palette colors, as well as white, tan, and gray. Whether it’s a simple split pipe seal or a complex prefabricated curb wrap, Carlisle can make it in all eight TPO colors and get it to the job quickly. In addition to being available in eight colors, here are some other great advantages to using custom flashings from Carlisle: • Save time vs. field fabrication: Trying to field-fabricate flashings can be time-consuming work, even for the most skilled and experienced roofers. Using prefabricated flashings saves time. • No need for paint: There’s no need to prime and paint the accessories to match the membrane; just install and go. • Speed: Custom accessories can be fabricated and shipped within days, not weeks. • Quality: All of Carlisle’s custom TPO accessories carry the Certified Fabricated Accessory (CFA) stamp of approval, indicating they are eligible for coverage as part of the Carlisle Total Roofing System Warranty. Next time you have a project using Carlisle’s TPO Color Palette TPO, consider using custom accessories to make the job faster and easier to install. Sure-Weld TPO Special Color Painting Guide  Sure-Weld TPO Special Color Program  Custom Accessory Quote Request Form      Adam Burzynski     TPO Product Manager     Product Marketing     [email protected]

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September 17, 2019
Solving Unique Challenges with a Hybrid Approach to Insulation

One of the simplest ways to meet building codes requirements in construction is through the effective use of insulation. There are several types of rooftop insulations available in the marketplace, but two of the most commonly accepted in commercial roofing applications are polyisocyanurate (polyiso) and expanded polystyrene (EPS). Polyiso is a lightweight and cost-effective, closed-cell, rigid foam board insulation that provides energy-efficient solutions for buildings in any region and climate, as well as outstanding return on investment and significant energy savings. EPS is a closed-cell, rigid foam insulation manufactured using expandable polystyrene. It is block-molded for most construction applications and is highly customizable, enabling thicknesses up to 40 inches in a single board. EPS is versatile and durable and can provide significant cost and labor advantages. Both polyiso and EPS provide great benefits and R-value in roof construction projects. However, projects often arise when a hybrid solution to insulation may be the most practical. A hybrid polyiso/EPS solution can help you edge out the competition in a number of scenarios. New Construction with Concrete Decks  A recent innovation introduced by Carlisle is ChannelDry® EPS Insulation. ChannelDry is ideal for new construction projects with structural concrete, lightweight structural concrete, and lightweight insulating concrete roof decks. Using ChannelDry in conjunction with one-way and two-way relief vents allows the installation of the roof system to begin upon structural cure of concrete (typically around 28 days). ChannelDry is compatible with ballasted, mechanically fastened, induction welded, and adhered single-ply roofing systems. The use of ChannelDry creates a problem-solving solution for new construction involving concrete decks, enabling construction to commence immediately upon structural cure. Standing Seam Metal Roofs  With square-, taper-, and profile-cut flute-fill products in custom shapes and sizes, a solution is available for all metal retrofit roofs. Combining EPS to fill the metal roof flutes with a subsequent layer of insulation or coverboard can create an ideal foundation for a retrofit roof. Click here to hear a contractor describe the benefits of this system from a project in Windsor, Ontario, Canada. Tapered Roof Design  A tapered roof is another ideal candidate for a hybrid approach to save time and money. With thicknesses up to 40" and virtually any slope available in a single board, a base layer of tapered EPS insulation can save nearly 30% in product cost alone, with additional savings on installation time when combined with polyiso. Combining polyiso and EPS in commercial roofing applications is an effective solution that can often save you money and labor on a project. Contact your local Carlisle representative to learn more.

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September 3, 2019
Roofing with Resilience: A Review of 30-Year EPDM Enhancements

The history of EPDM roofing runs deep. With over 50 years on the market and billions of square feet produced and installed, Carlisle SynTec’s EPDM has a proven track record as one of the most resilient membranes in the single-ply roofing industry today. As time goes on and the construction industry evolves, more sustainable structures are becoming the norm. Building codes are increasingly robust and are placing a greater emphasis on protecting your building from Mother Nature’s wrath. Your roof system plays a huge part in achieving compliance and serves as the first line of defense against hail, wind, and other damaging elements. This is where EPDM’s sustainability and durability come into to play. Sustainability and resiliency are some of the strongest attributes of Carlisle’s EPDM membranes, and EPDM’s durability allows us to offer a high-end, 30-year Total System Warranty that guarantees long-term performance. Below are the enhancements that Carlisle SynTec requires when upgrading to a 30-year EPDM system: 30-Year EPDM Enhancements The Membrane: The thicker and more durable 90-mil EPDM, 75-mil reinforced EPDM, or 145-mil FleeceBACK® EPDM are required; fully adhered, mechanically fastened, or ballasted designs are available. The thicker membranes will provide greater long-term performance and superior resistance to weathering. Please note, 45-mil and 60-mil membranes are not eligible for 30-year Total System Warranties. The Splices: Membrane splices are one of most important parts of any roofing system and utilizing our Factory-Applied Tape™ means more watertight seams and fewer warranty claims. On a 30-year EPDM system, Carlisle requires membrane with 6”-wide Factory-Applied Tape or 6” SecurTAPE™ to be installed at all seams and end laps. The 6”-wide tape has greater peel and sheer strength and results in a stronger bond. Please note, 3” factory-applied or hand-applied tape on 30-year warranties must be stripped in with Pressure-Sensitive Cured Cover Strip. The Flashing Details: In addition to seams, flashing details are critical to preventing issues where rooftop penetrations are tied in to the field membrane. On 30-year EPDM systems, Carlisle requires specific details to be double-wrapped or covered with two layers of flashing. Below is a list of these details: Key U = Universal (applies to all 30-year systems) A = Adhered Systems Only B = Ballasted Systems Only MF = Mechanically Fastened Systems Only U-2D SecurTAPE Splice Intersection (25-/30-Year Warranties) U-8A.1 Pre-Molded Pressure-Sensitive Pipe Seal with 90-mil Membrane or 25-/30-Year Warranties U-8B.1 Field Fabricated Pipe/Structural Steel Tube Flashing for 25-/30-Year Warranties U-15D.1 Inside Corner Flashing for Projects with 90-mil Membrane or 25-/30-Year Warranties U-15H Outside Corner Flashing for Projects with 90-mil Membrane or 25-/30-Year Warranties A-2 Membrane Splice (25-/30-Year Warranties) B-2 Membrane Splice (25-/30-Year Warranties) MF-2D Membrane Splice (25-/30-Year Warranties) MF-2E SecurTAPE Splice Intersection (25-/30-Year Warranties) ***Please speak with a Carlisle SynTec Design Analyst about additional 30-year requirements in regards to adhesives, coverboards, insulation, fastening density, perimeter securement, and metal edging.***     Ryan Ferguson     EPDM Product Specialist     Product Marketing     [email protected]

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