whether hot or cold, can change the physical properties of coatings, sealants, primers, and adhesives. Applying liquid-applied products outside their recommended temperature window may lead to performance issues. Equally important and related to temperature, the relative humidity should be 85% or less and ambient air temperature must be 5°F above the dew point at the time of application.
· Cold temperatures will increase the viscosity (thickness) of a product and hot temperatures will decrease viscosity. This can affect the rate of application, causing too much or too little product to be applied.
Application Rates Matter!
· Applying a product at the incorrect rate (too thick) can lengthen cure times (adhesives/primers), affect reflectivity (aluminum coatings),or cause blistering (solvent & water-based coatings).
· For products that cure by evaporation of solvent or water, warm air allows for quicker evaporation as long as the relative humidity is below 85% and the ambient air temperature is 5°F above the dew point. For moisture curing products, warm air holds more moisture helping trigger curing mechanisms. Colder air is dryer and holds less moisture so evaporation is slowed and moisture reliant curing is drawn out longer.
· Aluminum coatings require the sun’s heat to help the aluminum pigment leaf to the surface. As the solvent evaporates, the pigments remain on the coating surface to produce a consistent, reflective film.
· This is when moisture vapor condenses on the surface of a liquid-applied product due to evaporation of the solvent when applied in warm, humid, or cold, damp weather. The moisture layer will slow evaporation and curing and may affect the appearance and reflectivity of a coating.
RECOMMENDED APPLICATION TEMPERATURE CHART
Weather plays an important role in the application of liquid-applied roof products. Make sure you STAY WEATHER-AWARE by downloading a weather app to keep you informed of current conditions on your project site.
For any questions, contact KARNAK Technical Services at 800-526-4236 or firstname.lastname@example.org.