Masonry Joint Sealants

Concrete control joints and expansion joints open and close with heat and load, so an expansion joint filler has to stretch with them instead of cracking out of the joint. The polyurethane sealants here fill concrete and brickwork joints and keep that seal through seasonal movement.

Choosing a joint sealant

Movement capacity decides the pick. Sikaflex 11FC, Sikaflex Construction AP+ and Bostik Seal 'N' Flex One each carry plus and minus 25 percent movement on expansion and control joints. Fireban One cures as a low-modulus sealant for high-movement and fire-rated work. Put backing rod in the joint first to set the bead depth before you gun the sealant.

Where this range stops

These sealants close the joint; they do not rebuild damaged concrete around it. Cracks in the slab or wall itself belong in the crack injection range. Check the movement class and substrate notes on each product data sheet before you order.