Can be overpainted with most paint types or covered over with wallpaper; no sanding down required. Instructions: 125 One Hour Caulk should be at room temperature when you begin using the product. If the caulk has been stored in cool conditions it should be placed in a warm room / bucket of warm water before use to gently heat up to working temperature. Application Temp. Range +4°C to +40°C. Do not apply 125 One Hour Caulk at temperatures below +4°C.