A zinc or lead channel between two sloping sections of roof.

An impervious material usually plastic or foil placed on the warm side of any insulation material to prevent moisture penetration.

The edge of the roof where it meets the gable wall. Generally, where there is a roof verge the roof will project slightly beyond the wall.

A granular material with thermal insulating properties which is used as loose-fill loft insulation. It can also be mixed with cement to form a lightweight, fire-resistant concrete.

A plastic material widely used in the manufacture of easy-to-clean floor coverings. Also used as a protective covering on wallpapers designed for the kitchen or bathroom to increase its durability and to allow it to be wiped clean.

The unit of electromotive force.