Cavity walls are held together by metal ties bridging the gap between the inner and outer leaves. Older mild steel ties corrode, and as the rust expands it lifts the mortar joints, causing horizontal cracking. Eventually the ties can fail completely and the outer wall can bow away.
Where ties have failed, we install high-performance stainless steel replacement ties in the pattern required by current building regulations and, where necessary, isolate the old corroded ties so they stop expanding.
Where cracking has already occurred, structural crack stitching restores strength. Mortar joints are raked out, high-tensile stainless steel helical bars are bonded in with specialist resin, and the joints are repointed to match, giving a strong, discreet repair.