Abacus

The upper plate of a capital, upon which the architrave rests.

Abutment

A foundation; a support.

Acanthus

A leaf, the conventionalized form of which is used upon the Corinthian and composite orders of architecture.

Alburnam

Sap wood.

Anchor

Irons of special form used to fasten together timbers or masonry, or both.

Annulet

A small, flat fillet encircling a column.

Arcade

A series of arches; a long arched building.

Arch

A form of construction which is supported by the pressure of each member against those adjoining.

Architrave

The part of an entablature which rests upon the column. The term is also applied to door and window casings.

Arris

The edge formed by two concave surfaces meeting each other, as the edges which separate the flutes of a Doric column.

Arris Fillet

A triangular piece of wood so arranged as to conduct the water away from the joint between the roof and a chimney or other vertical projection; a cricket; a saddle.

Ashlar

A wall of cut stone.

Astragal

A small round molding surrounding a column. It is also applied to a molding used in laying off panels upon flat surfaces and for similar purposes.

Back Flaps

Oblong-shaped hinges, shorter than strap hinges but generally applied in the same manner.

Backing

The bevel upon the top edge of a hip rafter which allows the roofing boards to fit the top of the rafter without leaving a triangular hole between it and the back of the roof covering.

Balcony

A platform projecting from the side of a house, usually inclosed with a balustrade, and more or less embellished.

Baldachin

A canopy placed over doors, thrones, etc., and supported either from the wall or by columns.

Balloon Frame

The lightest form of construction, generally used only upon the cheapest grade of work.

Baluster

A small column used to support a rail.

Balustrade

A row of balusters with the rails, generally used for porches, etc.

Band

A low flat molding.

Bartizan

A small overhanging turret which projects from the angles of towers or other parts of a building.

Base

The bottom of a column; the finish of a room at the junction of the walls and floor.

Bast

The inner bark of a tree Baston. A round molding used in the base of a column; the torus.

Batten

A narrow strip of board.

Batter Board

A temporary framework used to assist in locating the corners when laying out a foundation. See Topic 3.

Battlement

A parapet used upon ancient fortresses, notched to give protection to those behind it.

Bay Window

A window projecting beyond the wall, sometimes called a bow window.

Bead

A small round molding.

Beam

A horizontal timber used to resist weight or to hold other timbers in their places.

Bedding

A filling of mortar, putty, or other substance in order to secure a firm bearing.

Bevel Board

Used in framing a roof to lay out bevels.

Blockings

Pieces of wood fitted and glued to the inside angle of a joint in order to strengthen it; glue blocks.

Boarding In

The process of nailing boards upon the outside studding of a house.

Bonding

The method of laying brick so that each course will strengthen the one below it and assist in binding the wall together.

Braces

Pieces fitted and firmly fastened at an angle with two others in order to strengthen the angle thus treated.

Bracket

A support for a shelf.

Break Joints

To arrange joints so that they will not come directly under or over the joints of adjoining pieces, as in shingling, siding, etc.

Brick Noggin

A few courses of brick laid dry at the bottom of a studded wall to prevent the passage of flames or vermin.

Bridge Measure

The distance across an angle from a given point upon each side of it; the hypotenuse of a right-angled triangle.

Bridging

Pieces fitted in pairs from the bottom of one floor joist to the top of the one next to it, and crossed to give additional strength to the flooring.

Building Paper

Cheap, thick paper, used for additional warmth in covering a building before the siding is put on.

Built Timber

A timber made of several small pieces and forming one of largo dimensions.

Buttress

A projecting support which adds to the strength of a wall.

Buttress, Flying

Used to strengthen a part of a building which is higher than the rest; a sort of curved brace.

Buttress, Hanging

A buttress supported upon a corbel.

Buttress Steps

Sometimes applied to a flight of closed string steps.

Cambium

The part of a tree between the bast and the sap wood, from which is developed the new wood each year.

Canopy

An ornamental projection over doors and windows.

Cantilever

A timber, stone, or metal beam which projects to form a support, and extends back far enough over its own support to carry its load safely.

Capital

The upper part of a column which supports the entablature, usually more or less ornamented.

Carriages, or Stringers

The supports of the steps and risers of a flight of stairs. The wall string is fastened to the wall, and the face string is upon the outside of the stairs.

Casement

A glazed sash or frame which opens upon hinges.

Casing

The trimming around a door or window opening, either outside or inside.

Castellated

Having turrets and battlements like a castle.

Casting

The bending of a board widthways; warping.

Catherine-wheel Window

A window divided into radiating sections.