TriggerFoam Pro is a one part polyurethane expanding foam which sets into its final form by using moisture present in the air. When installing the foam, consideration should be given to the 2-3 times expansion of the foam after it leaves the nozzle. The surface of the foam initially dries within 1-5 hours and becomes fully cured in 12-15 hours. TriggerFoam Pro sets well on ordinary surfaces such as concrete, brick, metal, etc. Surfaces do not require preparation and can also be damp. After installation, it is recommended that a full 24 hours elapse prior to scraping, sanding, staining or painting. The foam has a R-5 equivalent value when used in place of traditional installation methods.