This page of our online a to z glossary of DIY home improvement terms is for do-it-yourself terms beginning with the letter 'B'.
- Back-siphoning
- The siphoning of part of a plumbing system caused by the failure of mains water pressure.
- Backing
- Rubble used behind a finished masonry facing.
- Backsaw
- A small to medium size fine-toothed hand saw with a stiff steel or brass back used for accurate cutting.
- Bag graining
- A traditional paint finish created by dabbing the freshly-painted surface with a bag full of old rags.
- Balanced flue
- A ducting system that allows a heating appliance, such as a boiler, to draw fresh air from and discharge gases to the outside of a building.
- Ballast
- Coarse gravel of sand, grit and stones of fairly small size.
- Ballvalve
- Valve operated by a float that rises and falls with the water level in wc and cold water cisterns.
- Baluster
- One of a set of posts supporting a stair handrail.
- Banisters
- Also called balustrade. The protective barrier alongside a staircase or landing.
- Barge boards
- Sloping boards fixed to the gable end of a roof to protect the ends of the roof timbers.
- Basecoat
- A flat coat of paint over which a decorative glaze is applied.
- Basin wrench
- Long-handled wrench designed for working in awkward spaces.
- Bat (brickwork)
- A brick cut across its width.
- Batt
- A short cut length of glass-fibre or mineral-fibre insulant.
- Batten
- A narrow strip of softwood, often used as an invisible support.
- Batter
- The slope of the face of a wall that leans backwards or tapers from bottom to top.
- Bay window
- A window or group of windows of several shapes supported by a foundation outside the main wall of a building.
- Beading
- A narrow decorative moulding with a variety of uses, traditionally machined from hardwood.
- Beam
- A transversely-supporting structural member.
- Bedjoint
- A horizontal joint upon which bricks are placed.
- Belt sander
- A machine for removing old paint or finishing wood and metal.
- Bench hook
- A device to hold work in place on a bench which is used while sawing.
- Bending spring
- Long spring that fits inside or over copper pipes so they can be bent without collapsing the walls.
- Bevel
- Angle ground on the blade of a chisel or plane: angle at which a saw file is held during sharpening.
- Bevel-edge chisel
- Bevel-bladed chisel suitable for light woodworking.
- Bisect
- To divide into two equal parts.
- Blind nailing
- Nailing so that the heads are undiscernible on the work's surface.
- Blistering
- The formation of bubbles on painted or varnished surfaces.
- Blockboard
- Sheet material consisting of a core of wood strips, less than 25 mm wide, sandwiched between veneers. Made in various thicknesses and board sizes.
- Blowlamp
- Hand-held propane or butane gas canister with flame used for soldering work and softening old paint ready for stripping. Needs to be used with care.
- Blown
- Broken away, as when a layer of cement rendering has parted from a wall.
- Bolster chisel
- Wide, spade-shaped cold chisel designed for cutting bricks but often used for lifting floorboards.
A bolster chisel
- Bond
- In brickwork, this is a decorative system used to mortar bricks together to form a strong and cohesive wall.
- Bonding
- The joining of two surfaces or the agent which brings it about.
- Bore
- The internal diameter of a pipe or cylinder, or to drill a hole.
- Bowing
- Wood lengths bent out of true by uneven shrinkage or supporting heavy weights.
- Bracket
- A projecting support for a shelf or a strengthening device.
- Bradawl
- Small tool used to make starting holes for screws and nails and for piercing leather.
- Braze
- To join metal by the application of molten brass.
- Brick veneer
- A decorative exterior wall finish of one brick's depth against a wood frame.
- Bridging
- Pairs of diagonal braces fitted between floor joists which distribute the floor load.
- BTU
- British Thermal Unit - a measurement used in air conditioning. 1 BTU = 778.6 ft Ibs. Btu: British Thermal Unit. 1 Therm= 100,000 Btus.
- Buffing compound
- A wax bonded soft abrasive in stick form.
- Burr
- Some roughness or a small projection left on metal after it is cut.
- Butt
- To join two items together end-to-end without overlap.
- Butt joint
- The junction at which two pieces of timber meet.
- Buttercoat
- The top layer of cement render.
