BU578 Ventilation drying behind wall claddings (2014)

The most effective way of drying water absorbed on the back of a wall cladding is to allow air to pass through purpose-built vents and remove it by evaporation.

This bulletin explains how ventilation drying can be engineered into a wall.

The bulletin covers:

• air circulation behind wall cladding
• ventilation behind different cladding types - brick veneer, battened cavity walls and direct-fixed claddings
• how much moisture can ventilation drying deal with
• how does ventilation drying depend on the climate
• are some cladding types more leaky than others
• ventilation drying and rain leakage.