Penetrations

Tiles cut for penetrations through the roof should be provided with upstands and over-flashed for drainage from above without restricting the water flow.

The flashing should finish 15 mm beyond the tile head lap above the penetration and should be wide enough to cover the nearest tile rib or up-stand. When the construction is solid masonry or brickwork, and flashings cannot be installed under the wall cladding, a chased should be cut and an over-flashing installed in the chase to provide weather protection.