Wall Ties
Cavity walls have been used as a method of reducing dampness and improving thermal insulation since the early 1930's. These structures are stable and sound provided that the metal wall ties, tying the two leaves of brickwork together, remain firmly in place.
A deterioration of, or lack of, wall ties in a cavity wall considerably reduces the strength and stability of the wall.
Wall ties have been traditionally protected from corrosion by zinc galvanising. However, this protection has been of poor and variable quality, with the zinc coating being lost within 25 - 30 years allowing the surrounding air and moisture to attack the steel ties.
The corroding effect of the metal causes the wall ties to expand up to 6 times their original thickness. This creates pressure where they are embedded in the mortar and increases the probability of structural cracking and bowing of the wall.
Gullivers can inspect the existing wall ties by drilling through the outer wall and using an endoscope to see if corrosion, deterioration, or, indeed, snapping has taken place.
If it is found that the wall ties need replacing, Gullivers will drill out the old ties and replace them with Stainless Steel ties.
