In hot weather conditions, solvent-based cold adhesives can soften modified bitumen materials.When using PA-311 Adhesive in warmer temperatures, it is helpful to modify certain project staging and application techniques to enhance the appearance of the finished roof system. The following guidelines for Paradiene systems installed in PA-311 Adhesive should be used together with standard Siplast specifications, details and recommendations.
Job Set-up and Scheduling :
- Consider using PA-311 M in lieu of standard PA-311. PA-311 M softens the Paradiene layers to a lesser degree than standard PA-311 in warmer temperatures.
- On multi-level facilities, complete the higher roof levels first, working to lower levels.
- Consider applying both the Paradiene 20 and Paradiene 30 sheets in the same day, or installing the Paradiene 30 finish ply the day following the Paradiene 20 application. If this is not practical, schedule the Paradiene 30 application for early morning hours when surface temperatures are cooler.
- Staging the job to avoid construction traffic on the newly installed membrane is recommended. Newly installed membrane should be protected from material storage, repetitive foot traffic, and construction equipment until the adhesive is fully cured.
- Whenever practical, install flashing membranes in early morning hours when surface temperatures are cooler. When working in warmer conditions is unavoidable, or when there is excessive marring of the material’s surface, workmen installing the flashing membrane should work from a sheet of plywood or other panel to protect the finished roof membrane.
- Limit construction traffic over a newly applied membrane.
- Workmen walking across the roof should talc their shoes (in a talc box) to reduce the potential for tracking the surface of the Paradiene sheets
Application Guidelines :
- Squeegee blades should be inspected frequently for wear. If the notched or grooved pattern is not clearly visible, worn out blades must be changed to ensure the proper quantity of adhesive is applied.
- Application rates should be closely followed and monitored to ensure that coverage is within Siplast recommended application rates. More is not better. Recommended usage is 1½ to 2 gallons between plies and 1½ to 2½ gallons per square over insulation substrates.
- Regardless of ambient conditions, adhesive flash-off time can be reduced by warming the adhesive. Granules should be broadcast onto adhesive bleed-outs immediately following application while the adhesive is still wet to ensure proper embedment.
- Contact your local Siplast representative or the Siplast Technical Department at (800) 922-8800 with any questions.