Wall Tie Failure
What Are Wall Ties?
Wall ties are an essential part of the stability of a cavity wall structure - they tie its weather-protecting masonry façade to the main body of a building at regular spacings. An effective wall tie system transfers static and live loads across the cavity, which enables load-sharing by both inner and outer walls. Typically, cavity wall ties are bedded in the inner leaf mortar bed joint as a building is constructed - or in the mortar bed joint as the outer leaf is constructed.
As wall ties bridge between the two leafs of a building, they must be installed upwards when facing the outer leaf, to prevent water transferring across the cavity. Alternatively, most modern wall ties feature one or more "drip points" where water will drip from the tie, allowing for a more horizontal installation.
Wall ties should be designed to be resistent to corrosion from the weather (air/water), and the bed joints (cement).