Problems with Cavity Walls
The conventional cavity wall construction was intended originally to prevent problems of damp penetration of thin brick walls. It has since been adapted to meet successive changes in Building Regulations, most notably with the introduction of thermal insulation into the cavity.
With the latest changes in Part L it has become apparent that cavity wall construction may not be a practicable method of achieving the necessary standards of thermal performance:
- the thickness of thermal insulation requires wider cavities which, in turn, require longer and more wall ties to achieve structural stability;
- wider cavities may not comply with the Part E requirements for Robust Details;
- thicker walls will either reduce the available space within the building or increase the building footprint, thereby lowering the density of dwellings in a development;
- vents to the cavity results in high levels of air infiltration.
To avoid those and other problems designers should consider other forms of wall construction.
