Chases in walls

Chases in walls
Limit on the depth of chases
A. Vertical chases, indicated B on the above diagram, should not be deeper than 1/3 rd of the wall thickness or, in a cavity wall, 1/3 rd of the thickness of the relevant leaf.
B. Horizontal chases, indicated C on the above diagram, should not be deeper than 1/6 th of the wall thickness or, in a cavity wall, 1/6 th of the thickness of the relevant leaf.
C. Chases should not be so positioned as to impair the stability of the wall. Back to back chases are not permitted.
D. For hollow or cellular blocks maintain a residual thickness of 15mm between the chase and the void unless otherwise recommended by the manufacturer.

Please check with your local building control department before using information contained in this page to ensure that they comply with your local building codes.