Which is better for exterior sealant joints, urethane or silicone?
A. Unless the joint is to be coated or immersed, HCI recommends neutral cure silicone sealant for satisfactory long-term sealant performance. UV exposure can deteriorate urethane sealant within as few as three to five years in southern states. Up to twenty-year warranties are available for neutral cure silicone sealants.
