Carrying beam:

A large beam providing intermediate support for floor joists in place of a supporting wall.

Casement:

The hinged, opening section of a window.

Cavity wall:

A wall comprising two leaves of brickwork or masonry with a small gap between, usually bound together with cavity wall ties.

Cement fillet:

A narrow band of cement mortar around the base of a chimney stack at the junction with the roof covering, often used in place of flashings in an older building.

Chipboard flooring:

Larger manufactured flooring panels of a square or rectangular shape.

Cladding:

The outer facing of a wall, usually applied to a building or structure of framed construction.

Collar (or collar beam):

A horizontal tie beam extending between the two principal rafters of a roof truss at approximately mid-height, or between a pair of common rafters.

Combi boiler:

A central heating boiler which also provides domestic hot water directly from the mains, heated as it passes through the boiler.

Condensation:

The formation of water droplets on a cold surface in conditions of high humidity.

Condensing boiler:

A modern, efficient central heating boiler which, by means of a heat exchanger, reduces the amount of heat lost through the flue by cooling down the products of combustion.

Conduit:

A metal or plastic duct containing electrical cables.

Consumer unit:

The panel in an electrical installation on which the main fuses and trip switches are located, otherwise known as a distribution board or fuse box.

Coping stones:

Slabs of stone or concrete fixed onto the top of a wall either as a decorative capping piece or to throw off water from the face of the wall.

Coping:

A slab of stone or concrete at the top of the chimney, usually projecting beyond the face of the stack.

Corbelling:

A projecting course of brick or stone, or individual blocks of masonry built out from the top of a wall, usually supporting a gutter or other projecting structure.

Cornice gutter (or parapet gutter):

A gutter which is hidden from the ground, usually behind a decorative stone cornice or low parapet wall.

Cornice:

A decorative feature at the top of a wall, usually of stone construction and often concealing a hidden gutter.

Cowl:

A metal device fitted into the top of a chimney pot to prevent down-draughts.