Page "Brickwork" Paragraph 10

The third of three common strengthening devices has become almost ubiquitous in brickwork since the advent of the cavity wall during the mid nineteenth century.

A cavity wall comprises two totally discrete walls — each one of which is called a leaf.

A cavity separates the two leaves so that there is no masonry connection between them at all.

The transverse rigidity of this structure must therefore come from some source other than interlocking bricks, and the device used is the insertion at regular intervals of wall ties into the cavity wall ’ s mortar beds.