. CAVITY-WALL TIES

Material and Shape

Wall ties bond the two leaves of a cavity wall together to make the two act as one structural wall. Those in general use are made of galvanized mild steel or of stainless steel, but more modern ‘performance-type’ ties of superior strength and quality are also available, and these have started to supersede the more traditional ties.

Ties come in various sizes to suit different cavity widths and are specially shaped so as to form a drip at their centre. If moisture penetrates the outer wall and passes along the wall tie it will meet this drip, fall into the cavity and seep away through weepholes placed at the base of the outer skin of the cavity wall, below the horizontal damp proof course. Weepholes are also found above door and window openings and any other areas where a cavity is bridged (for example, by an airbrick and associated ducting).

. CAVITY-WALL TIES

Fig. 169 Examples of traditional cavity-wall ties.

. CAVITY-WALL TIES

Fig. 170 Modern performance-type cavity-wall ties. Ancon Building Products