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