CT1 Unique Sealant & Construction Adhesive – Grey is a versatile sealant which is resistant to vibration and it will not shrink. It can be applied onto a wet surface or even under water and unlike conventional silicone it can be painted or structured which is a perfect solution for repairing settlement cracks where fillers fail. It is a perfect for instant repairs as well as great for bonding lead to brick or felt to wood.