U V

Valley Board
Boarding fixed to the top of a roof valley rafter to form the support for a valley gutter.

Valley Gutter
Sheet metal gutter sloping along the valley surface of a roof.

Variation
An addition or omission to contracted works.

Ventilation
The supplying of outside air to an enclosed area.

Vitrified Clay Tile
A non-porous tile used in areas where low water absorption is required.