Choosing the right adhesive is critical, as many solvents can dissolve polystyrene.
- Compatible Adhesives:
- Water-Based Latex Adhesives: Specifically formulated for foam board insulation.
- Polyurethane-based Construction Adhesives: These are typically foam-safe (check label).
- Cementitious/Plaster-based Adhesives: Used for attaching XPS to masonry.
- Two-Part Epoxies: Generally safe.
- Adhesives to AVOID: Any adhesive containing solvents like acetone, gasoline, toluene, or certain types of contact cement.
- Compatible Sealants: Use water-based acrylic latex caulk, silicone sealant, or polyurethane sealant. Again, ensure they are labeled as compatible with polystyrene foam. Test a small area first if unsure.
