Black C-TEC CT1 sealant can be applied onto a wet surface 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 roof repair sealant and adhesive for bonding lead to brick or felt to wood. This product is the most environmentally safe sealant you can find as it is 100% Eco-Compliant with EC1 & EC1 A+ certificates, containing no petro chemicals which has enabled it to be accredited with a European food approved certificate.