B

Clay which has expanded during firing,owing to entrapped air or the breakdown of sulfides or other ingredients in the clay;light and porous;suitable for insulating aggregate in lightweight concrete.Also see expanded clay.
 

Masonry that is composed of irregularly shaped stones laid in a mass of mortar.

A pulley block,6 together with rope or cable,used to raise or shift a load. 

A flexural structural member,composed of individual concrete blocks which are joined together by prestressing.
 

Same as common bond.

In joining one part of a brick wall to another,the use of several courses of brickwork.

Same as cushion capital.

Same as block quoin.

A cornice used in Italian architecture;usually consists of a bed molding,a range of block modillions or corbels,and a corona or cornice (the bed molding may be omitted).

Blocks of wood which are used as paving or flooring.

A rigid or semirigid slab of thermal insulation.

See modillion.

A small scale simplified plan of a building,indicating its location and surroundings. 

A small plane,held in one hand;the angle of the cutting blade is low (usually about20);esp.used to clean up end grain and miters.
 

A quoin formed by bricks,distinguished decoratively from adjacent masonry by a contrasting appearance or by a projecting pattern.

In plumbing pure tin.

Hammer dressed stones (which may vary in length) having square faces,laid with close joints,in courses not exceeding 12 in. (30 cm) in height;used in heavy engineering masonry construction.

In a brick arch of concentric rings which is divided in sections,a bond within a section formed through the full depth of the archivolt by a block of bonded brick or by a voussoir inserted at intervals;ties together the concentric rings.

See coreboard;strip core.

The breaking of boulders by firing a charge of explosive that has been loaded in a drill hole.

1.A plain finishing course of masonry directly above a cornice.2.A string course.

In a concrete structure under construction,a space where concrete is not to be placed.

1.Masonry of concrete block and mortar.2.In timber and log construction,a technique for notching the corners of a house.

See bloom,4.

1.See throw,1.2.The eruption of  water and sand inside a cofferdam,causing flooding. 

1.The number of blows required to drive an object into soil.2.In soil borings,the number of blows required to advance a sample spoon 6 in. (15.2 cm) or 12 in.(30.5 cm).3.In pile driving,the number of blows required to advance the pile 12 in.(30.5 cm) or the number of blows per unit distance of advance.

1.Same as gas pocket.2.Same as bug hole.
 

On a boiler,an outlet to permit the discharge of accumulated deposits from water.

Localized buckling or shattering of rigid pavement caused by excessive longitudinal pressure.

A characteristic of a safety valve;the difference between the pressure at which it opens and the pressure at which it closes automatically,after the excess pressure has been released.
 

In an autoclave,the time taken to reduce the pressure from its maximum value to atmospheric pressure.

A fan,often heavy duty,used in HVACsystem applications.
 

In an  HVAC system,a  blower that moves an airstream across cooling coils,heating coils,and through an air filter.

1.See popping.2.The upward movement of soil material at the base of an excavation or cofferdam as a result of groundwater pressure.

British term for blowtorch.

On drawings,abbr.for boiler.

A small hole in a mold or plaster cast,formed by trapped air.

A hydraulic lime obtained by burning blue lias limestone.When mixed with water,it has a set which is not characteristic of regular limes.

A hard rock,bluish in color,which  is crushed and used in macadam.

A reproduction of a drawing by means of a contact printing process on light sensitive paper,producing a negative image consisting of white lines on a blue background;esp.refers to such reproductions of architectural drawings or working drawings used on construction sites.

A dark stain in the sapwood of some species of trees,usually caused by a fungus; it does not weaken the wood;also called sap stain. 

A stake which is driven into the ground,the top of which indicates the grade level.

Said of a steel nail surface that has been heated so that its surface takes on an oxidized bluish hue.

The addition of a small amount of clean blue colorant to a white paint to promote the visual perception of whiteness.

A white or grayish cast on high-gloss paint;results from the precipitation of binder solids owing to incompatibility with water,oil,or solvent.

1.On drawings,abbr.for bench mark.2.On drawings,abbr.for beam.
 

A type of carpentry work consisting of boards which are grooved along both edges and have thinner boards fitted between them.

In shotcrete construction,a joint which is formed by sloping the gunned surface to meet a board laid flat.

A board atop a wall plate that carries and distributes the load imposed on it by structural members supporting the roof.

A unit of cubic content used in measuring lumber;equal in volume to an area of 1 square foot having a thickness of 1 inch.