This page of our online a to z glossary of DIY home improvement terms is for do-it-yourself terms beginning with the letter 'D'.
- Dado rail
- Beading or panelling fixed on the lower half of a wall, well above the skirting. It is a traditional feature that has become popular in recent years.
- Damp proofing
- Treating a surface to prevent water seeping through.
- Distemper
- A type of paint made by mixing glue and water with size, whiting etc. Ready-made distemper is now out of commercial production, but you can make it yourself. Lighter in colour when dry than when applied.
- Doorhead
- The upper, horizontal part of a door's frame.
- Dormer window
- A window which projects out from a sloping roof.
- Double bend
- An S-shaped pipe fitting.
- Double glazing
- The setting of two parallel panes of glass in a window frame to reduce heat loss, external noise, etc.
- Downpipe
- A pipe, usually of metal, used to carry rainwater from the roof to the ground.
- DPM
- Damp-proof membrane, either under a floor screed or between outer and inner leaves of a cavity wall at openings to prevent moisture rising up.
- D.P.C.
- Damp proof course - a waterproof layer built into masonry to prevent rising damp, usually about 150 mm above ground level.
- Distressed effects
- Decorative paint techniques that make use of broken colours rather than solid ones. Examples are ragging and sponging.
- Dowel
- Short lengths of dowelling (tubular-shaped wood, sometimes grooved) used for joining wood.
- Dragging
- A decorative paint technique for walls and ceilings. After a colored base coat has dried you apply a glaze and, while this is still wet, you drag an almost-dry paintbrush across it.
- Drip groove
- A groove cut or moulded in the underside of a windowsill to prevent rainwater running back to the wall.
- Drop
- The distance of a vertical descent, such as a window or a table.
- Drop-in seat
- An upholstered board dropped into the frame of a chair.
- Drop pattern
- A wallpaper pattern in which the repeated images match up diagonally rather than horizontally.
- Dry brushing
- Process in which a glaze applied over a previously painted colour is stippled with a dry brush and then lightly brushed with a dusting brush while still wet.
- Dry laying
- Setting down tiles without using adhesive so that you can adjust pattern and positions before starting to fix the tiles into place.
- Dry lining
- An internal finish to walls composed of sheets of plasterboard rather than wet plaster.
- Dry rot
- The decay of timber brought about by fungal attacks in damp conditions. It appears as right-angled splits with a powdery appearance.
- Dynamic head
- The driving force generated by the central heating pump.
