DYCO PRODUCTS #20/20 RV ROOF SEAM SEALANT - Resealing your RVÃ¢â‚¬â„¢s seams and roof on an annual basis can prevent leaks and could prevent thousands of dollars of damage to your motor home, travel trailer, fifth wheel, or mobile home. 20/20 is a premium synthetic rubber brush on, solvent based caulk sealant used exclusively for sealing seams. Once applied 20/20 Seam Seal gradually forms a flexible water resistant elastometric seal making it ideal for seams around vents, stacks & attached structures such as carports. May be applied at freezing or above. 1 gallon will cover about 50-200 square feet of surface depending on thickness applied and smoothness of the seams. Not recommended for EPDM rubber roofs. Gallon, White.