Beam

A large and long piece of squared timber, used in horizontal positions for supporting a superincumbent weight, or for counteracting two opposite forces, tending either to stretch or to compress it in the direction of its length. Employed as a lintel, or for the support of the ends of joists in a floor, it simply sustains a weight; if employed as a tie-beam to the truss of a roof, it resists the strain or thrust exerted by the truss-rafters; or, if as a collar-beam between the heads of truss-rafters, it resists the strain they exert, and is compressed.

Beam-Compass

An instrument for describing circles of a larger diameter than may be practicable with ordinary compasses. It consists of a rod, or beam, on which are two sliding sockets, one provided with a sharp steel needle for fixing the centre of the circle to be described, and the other with a pencil for describing the circle itself. A very common method among carpenters for marking large circles, such as plans of domes, etc, is to determine the centre, and then affix to it the end of a slip or lath of wood, at the other extremity of which is the instrument for tracing the circle required.

Beam-Filling

The brickwork about the rafters at the eaves of a brick building.

Bearer

Any timber or wall that supports another timber, and retains it in its proper place.

Bearing

The distance or length which the ends of a timber or joist rest on another, or are inserted in a wall. A beam inserted 12 in. in a pier or wall is said to have a 12 in. bearing.

Beetle

A large and heavy wooden mallet or hammer for driving stakes, piles, wedges, etc. It has one, two, or three handles, as may be required.

Belfry

The part or section of a steeple in which the bell is suspended. The term was formerly used to denote more particularly the framing to which the bell was hung.

Bell-Roof

A roof the vertical section of which is concave at the bottom, and convex at the top. It is often called an ogee roof.

Belvtdere

A turret or lantern used for an observatory; also an arbor or artificial eminence in a garden.

Bevel

An instrument of the nature of a try-square, one leg being movable on a centre, so that it may be set at any angle. The term also denotes an angle which is more or less than a right angle.

Binding-Joists

In old methods of framing, binding-joists were large joists or timbers framed between the girders, in a transverse direction, for the support of the floor-joists above, and the ceiling-joists below. This method of framing is now but seldom used in this country.

Board

In America, a board is a piece of timber of any length or width, and from £ in. to 2 in. in thickness. Pieces of 2 or more in. up to 6 in. in thickness are called planks. In England, a board is a piece of timber more than 4 in. in width, and may be 2 1/2 in. thick; and all boards wider than 9 in. are called planks.

Boarding-Joists

The same as floor-joists.

Bolt

A square or round iron pin, with a head or flange at one end, and a thread and nut at the other.

Bond

Any thing that connects and retains two or more bodies in a particular position.

Bond-Timbers

The timbers or pieces of wood which are built into the walls of a brick or stone building to secure the internal finishing.

Boning

The act of judging and forming a plain surface or straight line by the eye. The art is usually termed sighting. Carpenters and joiners use for this purpose two straight edges, by which they determine whether the surface is true or twisted

Boring

The act of perforating any substance. In joinery, this is done with a brad-awl, gimlet, or bit; and in carpentry, by an auger.

Bow

Any part of a building that projects from a straight wall. It may be either circular or polygonal in plan: the last-named are termed canted bows.

Brace

A piece of timber fixed across the internal angle of the larger timbers of a frame; by which arrangement the whole of the work is stiffened, and the building prevented from swerving either way.

Break In

An old expression in use among carpenters, signifying the act of cutting or breaking a hole into a brick or stone wall to admit the ends of joists, beams, etc.

Breast-Summer

A piece of timber used for sustaining a superincumbent weight, and performing the office of a lintel over any large opening; as large windows, or doors in a store, or an open passage-way under the second story of a building.

Bbidge

A term denoting that one timber lies across and immediately upon another, or is notched into it. Thus, in framed roofing, the common rafters bridge over the purlins, and the purlins over the principal rafters.

Bridging

Pieces placed between timbers to prevent their nearer approach. In floors, the joists are often stayed in this manner by pieces of the same kind of joist cut and nailed in between them at right angles, or by narrow pieces of board placed in a similar position, and diagonally crossing each other.

Bridging-Floors

Those in whose construction bridging-joists are used.

Bridging-Joists

Those sustained by a beam beneath them.

Building

A fabric or edifice of any kind, constructed for occupancy; as a house, barn, church, etc.

Bulker

A term in use in some parts of England to denote a beam or rafter.

Butment-Cheeks

The two sides of a mortise in any piece of framing.

But-End

The end nearest the root of a tree.

Buttress

A pier or external support, designed to resist any pressure from within which may affect the wall or thing so supported.

C

Caliber

The greatest diameter of any round body; as of a log or ball, or the bore of a gun.

Camber

An arch or curve on the top of an aperture or of a beam. A beam is said to be cambered when it is hewn or bent so as to form a slight curve.