Pure, mould-resistant, acetic silicone sealant with BioBlock technology for movements up to 25%. Revamp your home with ease with the MAPEI Mapeisil AC 143 Terracotta Silicone Sealant 310ml. Backed by bio-block technology, this silicone sealant handles up to 25% movements while providing excellent mould resistance. It's highly elastic and perfect for sealing, filling gaps, bonding various surfaces together, and more. 310ml Mastic Cartridge Good adhesion to non-porous surfaces. This is a best-selling coloured mastic sealant, available in 38 different colours.