drainage cavity

The function of a drained cavity is to provide a back-upshould occasional water get past the cladding.

• the cavity is soley a secound line of defence should a failure of the weatherskin occur.
• minimum cavity depth of 20mm.
• specifying continuous vertical battens.
• ensure the cavity always drains outside the building.
• ensure the cavity is vermin-proofed.
• closinf off the top of the cavity from all roof and eaves spaces