Valley Flashings


Valley flashings are centrally folded, sloping internal gutters used where the roof pitch is more than 12°. They are required when the roof cladding changes direction at an internal corner or where a pitched dormer window penetrates the roof structure. (See Valley Gutters.)

Valleys should be fixed by clips to allow for longitudinal expansion, and should not be through fixed to the roof cladding.

A valley should be regarded as part of the roof cladding. All vertical valley laps should be sealed to avoid condensation accumulating at the top and to prevent the ingress of water by capillary action at the bottom of the lap.


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0 - Clause Removed
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Clause removed. Valleys are discussed in "Roof Drainage".

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