Can Waterproof Sealant be applied to Styrofoam? Yes, all the products are water based containing no solvents or VOC's. It can be applied to Styrofoam. Related articles Use in Concrete Cistern for Bathing? Can Waterproof Sealant be put on tarred surfaces? How come it feels tacky? Is it cured? Comments 0 comments Please sign in to leave a comment.