Deck-O-Seal® 4705012 11 oz One-Step Polysulfide Sealing Compound Tube 12 per Case. Seal all cracks and joints with DECK-O-SEAL two-part, elastomeric, polysulfide-based joint sealant. DECK-O-SEAL is used for caulking and sealing joints subject to concrete movement to provide a firm, flexible, weather-tight seal. It is ideal for sealing joints around swimming pools, and is applicable for both interior and exterior use. DECK-O-SEAL is highly resilient and has excellent recovery characteristics after extended periods of compression or elongation.