As temperatures fall and winter approaches, specifying and handling building envelope products – especially adhesives and primers – becomes a concern.
Low-VOC adhesives and primers contain more water than standard adhesives and primers and can be adversely affected by outside temperatures.
When specifying a low-VOC bonding adhesive or primer for a winter installation time frame, make sure to include information in the specification regarding cold weather application. This should include heated storage enclosures, or "hot boxes", for jobsite adhesive storage. This practice is strongly recommended when ambient temperatures are expected to fall below 40°F for an extended period of time.
Adhesives and primers should be stored in locations where temperatures are between 60°F and 80°F. While working with adhesives, they should be rotated in hot boxes to ensure the temperature of the product stays above 40°F. Adhesives may appear gelled or lumpy when left for extended periods of time at temperatures below 40°F. If this occurs, return the material to room temperature for a minimum of 24 hours prior to use.
In all applications, but especially in colder conditions, make sure you achieve the proper coverage rates for the adhesive or primer being used. Following coverage rates for Low-VOC adhesives and primers allows proper flash-off and reduces the trapped solvents which could lead to membrane blistering.
For applications in very cold temperatures, Flexible FAST™ Adhesive may be necessary. Flexible FAST is a two-part polyurethane foam adhesive which is spray-applied and used with a fleece-backed single-ply membrane. The advantage of this system is that it can be sprayed using 15- or 50-gallon drums of Part A and Part B, which can be heated using drum or band heaters. This allows the material to stay warmer during application and lowers the minimum application temperature to 25°F.
So for your next cold weather specification of Low-VOC adhesives and primers, include some installation precautions as mentioned. Contact Craig Tyler at [email protected] with further questions.