Dado
Panelling or decorative border covering the lower half of a wall, rising from the skirting board and often finished in a Rail.
Dado Rail
The Rail fixed along the top of a 'Dado'.
Damp proof course (D.P.C)
A layer of impervious material incorporated into the structure of the building at various positions in order to prevent damp conditions.
Damp proofing
The provision of a damp proof course or other means of preventing damp within a building.
Death-watch Beetle (Xestobium Rufovillosum)
A 'wood-boring insect' which attacks the sapwood of structural timbers (mostly hardwood) and is therefore difficult to eradicate.
Dehumidifier
An air conditioning unit that removes moisture from the air.
Door Furniture
Decorative fittings provided to a door, including knockers, handles, key escutcheons, letter boxs, and striking, finger or kick plates.
Door Jamb
The upright side members of a door frame.
Dormer
A projection, usually incorporating a window, through a sloping roof to provide additional space and light.
Double Glazing
A form of glazing incorporating two panes of glass separated by a cavity. Usually sealed factory units, sometimes filled with a gas. May also refer to secondary glazing provided to existing windows. Double glazing increases thermal and acoustic insulation.
Down-lighter
A light fixed or recessed into a ceiling to provide a downward illumination. Must be protected for fire safety.
Dry-lining
The lining provided to the inside of a building that does not need plastering other than over its scrim joints.
Dry Rot (Serpula Lacrymans)
Fungal outbreak that affects damp timber, particularly in dark, humid and unventilated areas. Its tendril roots (hyphae) can travel through masonry joints in search of a suitable timber food source, which makes it very destructive and difficult to eradicate.