Tim Bowers is the Installation and Training Manager at Flex-R, suppliers of RubberBond FleeceBack EPDM and LQD-PUR Polyurethane Liquid waterproofing systems for Specialist Registered Installer (SRI’s) and ClassicBond / ClassicBond PRO EPDM systems for stocking merchants. Tim, who has over 20 years of experience in the roofing and construction industry, offers some topical and timely tips for the trade when it comes to tackling cold-weather roof installations.
WINTER INSTALLATION TIPS FOR LIQUID ROOFING
#WINTERTIP 1. Installation Temperature
For most polyurethane (PU) liquid waterproofing systems application should occur at above 5°C. Industry standard curing times are at 20°C allowing the liquid to cure in a timely manner and with a cut off at 5°C. In colder months, the curing time increases so tackle smaller roof sections to better control the curing and ensuring an effective transfer before progress onto the next stage.
#WINTERTIP 2. Dew Point
Do not apply liquid systems at the dew point. The excess surface moisture will increase the risk of a compromised adhesion between the liquid and surface as well as affecting the curing time and product aesthetic. Dew point calculator apps are available to assist you to identify with when dew point is likely to occur. Early morning and late afternoon is typically when dew point is likely to occur.
#WINTERTIP 3. Product Storage
Polyurethanes are dense liquids, and if left out overnight in winter, they can become far colder than the recommended application temperature. This can make application and system coverage rates a challenge to achieve. They can also freeze.
#WINTERTIP 4. Spread the word – communicate well
You may think it obvious to your customers that a roof is more difficult to work on in cold weather, but it may also help to explain that the chemistry involved in the products used to install flat roof waterproofing system don’t work as effectively at very low temperatures.
#WINTERTIP 5. Tin Hat on the scaffold
If your customer is prepared to pay the extra for having a temporary cover over the scaffolding, be aware that it doesn’t always provide the solution in the wintertime for speeding a job up. Although the roof will be protected from snow or rain, as the area is shaded from sunshine the deck can take a long time to heat up to the correct installation temperature each day and condensation is also more likely to form.
WINTER INSTALLATION TIPS FOR EPDM SYSTEMS
#WINTERTIP 6. Warm the PS Tapes
To make your PS tape easy to work with, use an electric heat gun to warm it prior to installation in colder weather.
#WINTER TIP 7. Installation Tape Tip
During installation, when forming corners, the uncured tape stretches and forms better when the elongated diamond pattern is installed parallel to the deck membrane. Additionally, it helps to use the protective film as a separator when folding the corner in half to prevent the exposed tape edges from sticking to each other.
#WINTER TIP 8. Carlisle Lap Sealant
All Pressure Sensitive Uncured Tapes require Carlisle Lap Sealant to be applied and feathered over the entire edge where water may sit against it. Lap Sealant should be applied on the same day following installation. Applying, as a matter of course, prevents costly callbacks. Should the Lap Sealant be stored at temperatures below 15ºC, restore it to room temperature before use.
WINTER TIP 9. Keep Adhesives Warm
Keep your adhesives warm prior to and during application. WBA (Water Based Adhesive) should not be used when temperatures may drop below 5°C in the 24 hours following application, or freezing may occur, causing bond failures. Storing canister adhesives outside overnight in cold temperatures can cause the canister to lose pressure and become challenging to apply. All Flex-R adhesives cure better when applied warm.
#WINTER TIP 10. EPDM Primer
Prior to application of EPDM Primer, it is advised to heat/warm the target area with an electric heat gun to ensure the chemical bond is not affected by lower temperatures. Should application temperature be below 5°C, use your heat gun to bring the membrane back to at least 18°C.
