| ARCHITECTURAL DICTIONARY | |||||||||
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B
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| Board Measure | The superficial measurement of a quantity of timber |
| Board-finish plaster | Usually a low expansion retarded hemihydrate plaster, suitable for single coat finishing work on true surface such as gypsum plasterboard. It is one of the few plasters to which lime should never be added |
| Boarding Joists | Common Joists for floorboarding |
| Boarding, sheathing boards | Boards laid side by side |
| Boasted Ashlar | A rough finish to stonework made by boasting |
| Boaster | A mason's boasting chisel, 40 to 80 mm wide, struck by a mallet in dressing stone |
| Boasting | The hand wasting or rough dressing of the surface with oblique or vertical strokes, which are usually not uniform, from a boaster |
| Boil resistant adhesive | An adhesive with good water resistance, able to withstand hot water for many years also attracts by insects and fungi |
| Boiler | A water heater in which the water should not boil. A boiler is used for the production of domestic hot water and hot water for central heating |
| Boiler House | A plantroom for housing boilers |
| Bolster | A broad based steel brick layer's chisel with a blade about 110 mm wide |
| Bolt |
1) A fastener with a head and screw thread, for a nut 2) The tongue of the lock that prevents the door opening when it is out (thrown) and allows it to open when withdrawn 3) Hardware to hold door or shutter closed, usually with direct or simple action |
| Bolt Box | Formwork round foundation holding down bolts for structure steelwork, to make a pocket in the concrete. During Concreting the bolts may move out of position by up to 20 mm. After the concrete hardens steelwork is erected, with the bolts passing through holes in each baseplate. The pocket formed by the bolt box allows the baseplate to be moved into its right place. Later the bolt boxes are grouted |
| Bolt Croppers | A pair of hand shears used for cutting bolts or steel rods |
| Bond | The layout of courses of bricks or blocks in a wall. It is important to keep every vertical joint at least a quarter length of a brick or stone from the next vertical joint above or below, using bats and closers. |
| Bond Beam | A reinforced concrete beam made inside a course of hollow blockwork from which the block ends and internal walls have been removed. The beam ties the wall together |
| Bond Course | A course of headers in a brickwork or blockwork wall |
| Bonding | The use of high strength adhesive usually thermosetting resins, elstomers or thermoplastics to make permanent structural joints, composite metal members, prefabricated building panels etc. |
| Bonding compound | Hot molten blown bitumen put on to a roof to stick layers of built-up roofing together. A sealing compound is similar but is applied cold |
| Bonding Plaster | A pre-mixed light weight gypsum plaster containing exfoliated vermiculite, used as the undercoat in two-coat work on surfaces difficult to bond, such as smooth formed concrete walls |
| Bonding Tape | Tape glued on both faces for joining sheet materials in damp-proof courses, vapour barriers (to control humidity, smell etc). The tapes could be of bitumen felt, polyethylene |
| Bonding Treatment | Any treatment of a surface before the application of a finish (paint, plaster) so that it will stick. E.g. Roughing up the wall surface before plastering |
| Boning | The use of T shaped rods for setting out a flat surface, for excavations, ground slabs, drain laying etc. |
| Boning Pegs | Small hardwood pegs that are placed at the edges of large stones to be dressed flat, used with winding strips as guides |
| Boom | The jib of a crane, the dipper arm of a backhoe |
| Booster |
1) A pump for increasing the pressure in a water supply pipe or fire riser. 2) A heating element in an electric storage water heater which is switched on during the day if the draw-off temperature drops too low |
| Boot | A step down formed in the edge of a concrete floor slab (or a beam or lintel) to carry the outer skin of a cavity wall. This allows a drop in the damproof course to drain rainwater outwards through weepholes in the facing brickwork. The movement joint under the boot is weatherproofed with a sealant and the boot's outside face may be concealed with brick slips |
| Boot Lintel | A lintel across a door or window opening, with a boot |
| Booth | A small room or cubicle, for privacy or isolation, often with sound insulation |
| Bore |
1) To pierce so as to form a hole. 2) To drill a hole, or the hole after it is drilled 3) The internal diameter of a hole or a pipe. Copper pipe for water supply is mainly Microbore |
| Bore Lock ( Key-in-knob set, tubular mortice) | A door lock with a tubular T-shaped case. It fits into a bored mortice made with a hole saw from the face and with a drill from the stile, which is easier than cutting a rectangular mortice |
| Borer (Woodworm) | Wood-boring beetles in the larval phase, which burrow into timber for food and shelter, leaving behind wormholes when they emerge as adults e.g. furniture beetle, longhorn beetle etc. Treatment against attack using preservatives usually does not penetrate deeply enough to reach all borers, but they are killed by high temperatures, as in kiln dried timbers |
| Borosilicate Glass | Heat and chemical resistant clear glass made from borax as well as the usual silica, giving complex compounds of sodium borosilicate. It is used in factory shaped and tempered fire resisting glass, as glassfibre, to make vitreous enamel and in glass drain pipes |
| Bottle Trap | A trap on the waste from a kitchen sink or bathroom basin which has a bottle shaped cap that can be removed to clean out any rubbish causing a blockage, such as matches, hairpins and hair. Bottle traps are usually less self cleansing than a tubular S-trap |
| Bottom Chord | The lowest member of truss or girder |
| Bottom Plate | A member along the bottom of a framed partition that spreads the loads from the studs to the supporting floor |
| Bottom Rail | The horizontal bottom member of a framed door, casement or lower sash |
| Bottom Tie | A base tie of a pressed metal door frame |
| Bottom Ventilation | An air inlet for natural ventilation, particularly to a plantroom or machinery enclosure |
| Bottom-hung window | A window with its opening sash hinged at the bottom |
| Bottoming | Hand trimming excavations with a shovel, working behind an excavator such as backhoe, to clean out lumps of dirt and leave a tidy formation |
| Bottomless hole | A hole which passes through a material. It is therefore difficult to make a fixing in it except with a toggle bolt, anchor etc |
| Boundary | The edge of a building site |
| Bow Window | A projecting Bay Window which is curved in Plan |
| Bowl |
1) The part of a sanitary fitting made to contain water, usually with a waste outlet. Kitchen sinks may have one or two bowls. A bowl of a WC is also called the pan 2) A light diffuser over a luminaire, often made from acrylic sheet |
| Bowl Saw | An ancient type of saw with a thin blade held at both ends in a loose H frame and tightened with twisted wire or string |
| Bowl,urinal, pod | A rounded vitreous china urinal, usually rimless and wall hung at varying heights to suit users |
| Box Cornice | The edge of a roof built out to conceal the gutter, with a fascia in front and a soffit board underneath |
| Box Frame | A sash window cased frame |
| Box Gutter / trough | A roof gutter below the general level of the roofing, with a lining in supported sheetmetal roofing, or bitumen roofing felt over a wooden box. Box gutters should always have a safety overflow, such as a scrapper through a parapet, so that if the outlet becomes blocked with leaves or snow, the rainwater will not flood though the ceiling or overload the roof |
| Boxed Heart | The heart centre, usually within a 100 mm square, cut out during the conversion of timber and discarded, This is done with some eucalyptus hardwoods, which have poor heart |
| Boxing | A formwork box, or a casing of building board on ground or studs |
| Boxwood | A hard hardwood used for making chisel handles |
| BQ,BOQ | Bill of quantities |
| Brace | A strut or tie that stabilizes other members, usually placed so that a triangle is formed, e.g. a knee brace, the braces on a matchboard door, temporary braces during construction etc. |
| Braced Frame | A structural timber building frame with widely spaced, heavy posts and beams and girders which carry main loads. It has infill walls, which are non load bearing. Bracing for structural stability comes partly from the joint between the posts and beams, although additional cross-bracing can be concealed in the walls |
| Bracket | A support for a shelf, projecting from a wall. |
| Bracket Arm | An outreach arm |
| Bracket Lamp | A wall-hung Lamp |
| Bracket Scaffold | A scaffold carried on brackets bolted to a wall |
| Bracketed Stairs | Stairs with treads carried on a cut string, usually with overhanging nosings |
| Brad |
1) A wire nail usually 50 to 65 mm long, with rounded built head 2) A cut nail of constant thickness but tapering width, with a square head projecting from one edge only, or an oval-wire brad |
| Bradder | A small nail gun that drives brads up to about 65 mm long |
| Braided Cable | Flexible flat cable made from several strands of bare copper wire plaited together, used for the earth bonding of moving parts, e.g. switchboard doors |
| Bracket |
1) A projecting support usually fixed to a wall or column, Stair handrails are often on metalwork brackets. Pipework can be supported by brackets with two piece cleats 2) A short vertical board fixed to the carriage of a timber stair to support the tread directly |
| Branch | A secondary pipe or cable connected to a main in a distribution or collection system, such as water supply, drainage, sewerage or electrical circuits |
| Branch Circuit | The electrical wiring to power or lighting use points, from the fuses in the distribution board, usually run as either a ring main or a radial circuit |
| Branch Manhole | A manhole in which a branch connection is made |
| Branch Pipe, discharge pipe | A branch to carry soil water or waste water to the stack |
| Branch Vent | A pipe which admits air to the downstream side of the water seal in a trap the start of a drain. Usually it is run upwards to the stack vent, which lets in air through its top end. The branch vent prevents unsealing of the trap as a flush of water passes down the soil stack, e.g. as in a one-pipe system of sanitary pipework |
| Brash timber, Brashy | Timber which breaks with small resistance to shock and little or no splintering. This short grain may be due to fungus |
| Brass | A metal alloy made from a mixture of copper and zinc, often with small amounts of nickel, lead iron, etc, used in traditional builder's hardware and some pipe fittings. Brasses are mostly easily formed, strong and corrosion resistant, but are best not used with other metals, which could cause dezincification |
| Brazilian Mahogany | True Mahogany, a close grained red timber with fine silky texture, hard and very little moisture movement. It is stronger than oak but slightly easier to work and used for best joinery |
| Brazing | A generally simple, inexpensive way of joining metals using a copper- zinc filler metal (hard solder) which melts above 500deg c, normally with an oxy-acetylene flame. The two surfaces need suitable preparation, usually limited to thorough cleaning. A flux is also needed. Brazing, particularly silver brazing, us widely used for capillary joints in copper tube or brass pipe. Brazed steel joints are not as strong as welded ones |
| Break Draught Damper | A flue damper |
| Break glass unit | A manual fire alarm call point with a breakable glass cover. |
| Break joints | Staggered joints |
| Break out | To cut away part of a building fabric to make a secure connection with new work, e.g. the toothing of brickwork or the exposing of reinforcement bars |
| Breaker | A power tool for breaking rocks, concrete or roads by forcefully hammering a pick or similar tool. It can be a hydraulic, pneumatic or electric hand held jackhammer or a mounted backhoe |
| Breaker Slab | A clay or concrete slab in the backfill over buried cables, to indicate their presence, in the same way as a tracer |
| Breaking Down | The first of two stages in conversion of timber, in which the log is sawn into squared flitches |
| Breaking of seal | The unsealing of traps |
| Breast |
1) A projection of a wall into a room, containing the flue and hearth of a fireplace 2) The wall under a window sill, down to the floor |
| Breast Drill | A large hand drill operated with both hands, with an extension and plate for thrust from the user's chest |
| Breather Hole | A tiny hole from the air space between secondary glazing out to the cold side, where the air contains less moisture in winter, even at a higher relative humidity. As atmospheric pressure rises and falls, the air space gradually fills with dryer air, reducing condensation, but dirt and insects may enter unless the holes have a filter e.g. a porous tape |
| Breather Membrane | A building paper that is microporous to allow ventilation and the escape of water vapour. It is put on over the outside of heat insulation and under the external cladding of a timber framed wall (or roof). It also helps prevent driving rain from passing inwards. Breather membranes must be on the 'cold' side of the wall, i.e. on the opposite side of the framing to its vapour barrier |
| Breech Fitting | A junction pipe fitting |
| Breeching | A double inlet to a dry riser accessible from the street |
| Breeze Block | A building Block formerly made with coke breeze from gas works. It is superseded by the clinker block |
| Breezeway | A covered walk between buildings |
| Bressummer | A long heavy Lintel across an opening, to carry the wall above. It is generally not used nowadays. It was usually made of Timber |
| Brick |
A
rectangular block usually so sized so that it can be easily held in one
hand. They are generally proportioned for the lengths of each side (face,
bed and end) to form multiples, forming Bonds.
Building bricks vary widely in strength, durability and appearance from
the most costly engineering bricks
or facing bricks to commons.
They are mostly used to build walls and vary in type from solid to frogged,
cellular, perforated and hollow.
Bricks shaped differently from the normal full brick are called specials.
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| Brick axe | A bricklayer's hammer |
| Brick Damp Course | A damp-proof course in a wall made from two courses of damp-proof course bricks, or engineering bricks with a water absorption of less than 7% laid with staggered joints in 1:1/4:3 cement:lime:sand mortar. The mortar should not carry any plasticizer as this may reduce adhesion. As brick damp courses are more rigid and resist tension better than other types, they are suitable for freestanding walls |
| Brick Elevator | Mobile Contractor's plant used for raising building material to a scaffold. It has a rubber belt and steel cleats to stop brick slipping at steep angles |
| Brick nogging, brick partition wall | Non-Load bearing wall, usually infilling between the columns or a steel framed building. The wall is generally constructed by bricks on edge. Wall ties and movement joints are needed for them |
| Brick Tie | A wall tie |
| Brick trowel | A long tapering triangular trowel held in one hand for bedding and jointing bricks |
| Brickbat |
1) A brick cut across and shorter than full length, used to complete a bond 2) A bat |
| Bricklayer | A person who builds and repairs brickwork (bricklaying), on large projects usually working as part of a gang under a foreman bricklayer |
| Bricklayer's Hammer | A small hammer with sharp cross-peen as well as the striking face, used for breaking and dressing bricks |
| Bricklayer's Line (Soot) | A line used as a guide during bricklaying |
| Bricklayer's Scaffold | A scaffold supported by putlogs, which have a flattened end to fit into raked-out holes in the bed joints, the other end being carried on ledgers held up by the standards |
| Bricklaying | The art of laying bricks in courses to make brickwork by bedding and jointing with cement mortar. Joints are usually shoved and the bricks kept true and plumb by working to a bricklayer's line, which is stretched between profiles |
| Brick-on-edge | Brickwork, usually of headers, laid on edge for a capping or sill |
| Brickwork | A wall made up of courses of bricks laid in mortar according to a bond. |
| Brickwork Beam | A concealed lintel made by inserting reinforcement in bottom bed course of brickwork over an opening, for clear spans upto 2.1 Mt |
| Brickwork Chaser | A power tool that cuts a neat chase in brickwork to receive electrical conduit or a pipe |
| Bridging |
1) The spanning of a gap with common joists 2) The stiffening of adjacent wooden floor joists by a row of solid bridging or herring-bone strutting at right angles to the joists. |
| Bright |
1) A description of freshly sawn timber without discolouration 2) Steel with low surface oxidation |
| Brilliance |
1) The cleanness and brightness of a colour 2) The clearness of a varnish or lacquer; the absence of opalescence and similar defects |
| Brise Soleil | A French term for a permanent sun shade (Horizontal or vertical blades, decorative screen walls) outside an external wall |
| Broach |
1) The pin in the keyhole of lock with a hollow key 2) A pointed mason's chisel used for wasting stone |
| Broadloom Carpet | Fabric floor covering in rolls 2.50 to 4.00 Mt wide. |
| Broken Bond | Brickwork or Blockwork which is not entirely built to format, it has bats in the courses rather than full bricks. |
| Bronze | A hard, corrosion resistant alloy of copper and usually tin, sometimes with other elements |
| Broom-finish concrete | A floor slab that is floated and trowelled smooth, then finished by drawing a stiff broom across it to make it a non slip surface |
| Brooming | Scratching a floating coat with a stiff broom to make a key for plaster, or giving a broom finish to concrete |
| Brush | Paint brushes are made from synthetic fibres or animal bristles (Stiff Hairs) held on to a handle, usually with a metal ring or ferrule. The bristles of larger brushes may be set in synthetic resin |
| Brush Seal | A long Strip of bristles fixed to project from the edge of a door leaf, as a wiping seal for weather-stripping or for smoke control |
| Brushability | The ease with which paint can be applied by brushing. Brushable paints are not gummy, do not cause ropiness and enable a live edge to be easily picked up |
| Brutalism | Functionalist style of the 1950's -60's that left materials such as concrete determinedly undistinguished. |