RetroFit RetroFit Is an Open Cell Foam that remains in it’s liquid form longer, in order for the material to run down the stud bay, then expands and fills the bay with insulation foam. Benefits Expands 125-150 timesSeals all openingsR-Value of 3.5 per inchNot a Food Source for MoldGreat for Over the Air SoundProofing Recommended Uses Drafty Exterior wallsHomes with No or Failed InsulationPartition walls between rooms Contact Us