Fosroc Nitoseal PU40 Low-Modulus Polyurethane Expansion Joint Sealant (600 ml * 20 pcs)

An expansion joint exists so the structure can move, which means the sealant in it has to stretch and compress over and over without tearing or peeling off the joint faces. The joints between concrete panels, precast segments and stone cladding open and close with heat and load every day. Fosroc Nitoseal PU40 from Fosroc is the low-modulus polyurethane sealant rated for that movement, built to flex with the joint instead of cracking across it.

It's a one-part, gun-grade polyurethane that cures to a soft, low-modulus rubber, so it accommodates joint movement of around 25 percent without putting stress on the bond. It's certified to ISO 11600 F 25LM for construction joints, holds its seal across joints from 5 to 35mm wide, and bonds to most building materials without a primer on standard work. It's also very UV resistant, so it lasts on exposed facades and external joints where the sun would degrade a lesser sealant.

That puts it on expansion and movement joints in concrete, brickwork and blockwork, between precast panels and stone cladding, around door and window perimeters, and on non-trafficked floor joints. It seals those joints watertight against seepage and wind-driven rain, and for high-movement or immersed joints a Fosroc primer brings the adhesion up to the demand.

For expansion joints that have to move and stay sealed, Fosroc Nitoseal PU40 is the low-modulus polyurethane sealant rated to flex with them and hold the weather out.