How We Install Wall Ties
The corrosion problem of wall ties was first officially recognised in the 1960’s in South Wales. At first it was thought to be a combination of poor tie protection and exposure to the elements but time has shown that many of the early ties and mortars were just more susceptible to corrosion.
Ferrous oxide ( rust ) will result when embedded mild steel wall ties corrode. This will expand to several times the thickness of the metal that has rusted and results in lifting of the brickwork above and cracks along the relevant mortar course. From a structural perspective, this leaves the wall vulnerable to vertical and wind loads especially in the case of large gable walls and unreturned walls.
The replacement process involves the identification of the existing wall ties using a metal detector and marking the positions of these. New stainless steel wall ties are installed by usually drilling from the external leaf and fitting replacement wall ties in a pattern to match current Building Regulations which is usually 450mm staggered centres and at 300mm centres vertically at opening such as window and doors.
The new replacement wall ties can be either mechanically anchored or fixed with resin.