Bachelor Dwelling Unit – A unit, with not more than one bedroom, providing therein living, sleeping, eating, food preparation and sanitary facilities for one or two adults Other essential facilities and services may be shared with other dwelling units.

Back Bedding – See “Back Putty”.

Backfill – The material used for a trench or around a foundation wall to replace the void left by excavation.

Backflow – Defined under “Plumbing Terms.”

Backing – Material used to provide reinforcement or a nailing surface for certain finish materials.

Back Putty – Mastic material placed in rabbets before installing glass to provide a bed for the glass.

Back Siphonage – Defined under “Plumbing Terms”.

Balance – Defined under “Windows, Part of”.

Balcony – A platform projecting from the face of a wall, either cantilevered or supported by columns or brackets, and surrounded by a balustrade or railing.

Balloon Framing – Defined under “Wood Framing”.

Baluster – Vertical members in a balustrade between the handrail and the treads or stringers in a staircase.

Balustrade – A protective barrier approximately 3 feet to 4 feet high at the edge of openings in floors or at the side of stairs, landings, balconies, mezzanines, galleries, raised walkways, or other locations to prevent accidental falls from one level to another. Such barrier may be solid or may have openings through it.

Banister – The handrail of a staircase.

Barge Board – The finished board covering the gable rafter on a gable roof. See “Facer Board”, “Verge Board”.

Baseboard – Interior trim at the intersection of the wall and the floor.

Baseboard Heater – Defined under “Heating”.

Base Course – In masonry the first or bottom course of masonry units.

Basement – The lower storey of a building below or partly below ground level.

Base Moulding – Any moulding placed at the base of a column, wall, etc. See “Shoe Mould”.

Bat – In masonry a piece of brick with one end whole, the other end broken off.

Batt – A semi-rigid section of mineral wood anchored to paper, that is fixed between framed members. See “Friction Fit Batt”.

Batten – A narrow strip of wood used to cover joints between boards or panels.

Batter – A receding upward slope. A term normally applied to a wall or structural member where the thickness diminishes towards the top.

Batter Board – Boards set adjacent to an excavation and used to level and align the work.

Bay – One of the intervals or spaces into that a building is divided by columns, piers or division walls.
Bay Window – Defined under “Window Types”.

Beam – A structural member supported at two or more points, but not throughout its full length.

Beam Pocket – A notch or space normally in a masonry or concrete wall ion, that the end of the beam is supported.

Bearing Plate – A plate provided to distribute the load imposed by a specific member or members. Normally a steel plate set on concrete or masonry to support a structural member.

Bearing Wall or Partition – A wall that supports any vertical load in addition to its own weight.

Bed – In masonry, the horizontal layer of mortar on that each course of masonry is laid. Generally any horizontal surface that has been prepared to receive the elements it will support.

Bed Joints – The horizontal joints in brick-work or masonry; the radiating joints in an arch.

Bed-Moulding – Any moulding used to cover the joint at the intersection of a wall and projecting cornice.

Bench Mark – A durable post, block or that device established by surveyors to indicate a definite point from that elevations are set.

Bending Stress – A force causing a deflection in shape or position of any member of a structure.

Bent – Defined under “Truss Terminology”.

Bevel – The sloping surface formed when two surfaces meet at an angle other than a right angle.

Bevel Sliding – Boards normally 4 to 12 inches in width tapering to a thing edge, and used as covering for sides of buildings, the thick edge overlapping the thinner edge.

Bib – Commonly known as a hose bib. A tap or faucet that has been threaded for connection of a hose.

Bleeding – An exudation of resin, gum, creosote or other substance in lumber.

Blemish – Anything marring the appearance of wood.

Blind-Nailing – Nailing in such a way that the nail heads are not finally visible on the face of the work.

Blistering – Defined under “Paint”.

Block – In masonry, a manufactured concrete unit in that various types of aggregate may be used.

Block, Cellular – A block having uniformly distributed pores throughout its mass.

Block Plan – A plan of a building site showing the outlines of existing and proposed buildings.

Blowing – A plastering defect in that a conical piece may be blown out of a finished surface owing to moisture getting to an imperfectly slaked particle of quicklime in the mixture. Also called pitting.

Blue-Stain – A bluish discoloration of lumber, caused by certain fungi, that seldom penetrates beyond the sapwood.

Board – A piece of wood cut to dimensions, of considerably greater length and breadth when compared to its thickness. To cover with boards or a board.

Board Foot – The volume of a piece of wood one inch thick, one foot wide and one foot long, equivalent to 144 cubic inches.

Board Measure – A system of measurement of timber and lumber in that the unit is the board foot.

Bond – In masonry, the pattern in that bricks or blocks are laid to tie the individual units together so that the entire wall they comprise will tend to act as a complete unit.

Bottom Plate – The lower horizontal member of a wood-frame wall nailed to the bottom of the wall studs and to the floor-framing members.

Bowling – A deviation flat wise from a straight line drawn from end to end of a piece. It is measured at the point of greatest distance from the straight line.

Box Beam – A beam made of plywood on a lumber framework.

Box Column – A built-up hollow column of square or rectangular section generally used in porch construction.

Box Gutter – A wooden gutter usually lined with metal having upright sides, sometimes called concealed gutter.

Brace – In carpentry an inclined piece of timber used in walls and in trussed partitions or in framed roofs to form a triangle and thereby stiffen the framing. When a brace is used by way of support to a rafter it is called a strut.

Braced Farming – Supported framework of a house, especially at corners.

Bracing – The ties used for supporting and strengthening the various types of buildings.

Brads – Defined under “Nails”. S

Branch (Plumbing) Defined under “Plumbing Terms”.

Bracing – The ties used for supporting and strengthening the various types of buildings.

Brads – Defined under “Nails”.

Breaking Joints – The manner of laying masonry units so as to avoid vertical joints in adjacent courses from lining up. Also the distribution of joints in lumber sheathing, flooring, lath, and panels so no two adjacent end-joints are directly in line. Also known as “Staggered Joint” or “Step Joint”.

Breeze-Way – A covered passage-way between a house and an auxiliary building.

Brick Construction – Defined under “Construction types”.

Brick Facing – See “Brick Veneer”.

Brick Veneer – A facing of brick tied to a wood-frame, masonry or concrete wall, serving as a wall covering only and carrying no structural loads.

Bridging – Defined under “Wood Framing”.

Bridging (Cross) – Small wood or metal members that are inserted in a diagonal position between adjacent floor or roof joists.

British Thermal Unit – The amount of heat required to raise the temperature of one pound of pure water one degree Fahrenheit.

Broken Joints – A system of staggering joints so that no two of them in successive rows are directly opposite each other. Also known as “Staggered Joints” or “Step Joints”.

B.T.U. – An abbreviation for British Thermal Unit.

Building Area – The greatest horizontal projected area of a building at or above grade within the outside perimeter of the exterior walls or within the outside perimeter of the exterior walls and the center line of fire walls.

Building Drain – Defined under “Plumbing Terms”.

Building Maisonette – A form of horizontal multiple housing in that one dwelling shares three party walls with adjacent dwellings, one wall of that may be an internal corridor. Access to the dwelling is at grade, to either the exterior or the corridor, or both.  S

Building Paper – A breather type sheathing paper usually applied underneath or behind exterior finish material in wood-frame construction.

Building Sewer – Defined under “Plumbing Terms”.

Building Site – A parcel of land suitable for building, or on that a building is or may be built, including all surrounding land specifically allocated to the building.

Building Trap – Defined under “Plumbing Terms”.

Built-Up Roof – A roof covering consisting of layers of roofing felt laid in pitch or asphalt. The top is finished with crushed stone, gravel or a cap sheet. Generally used on flat or low-pitch roofs.

Bulkhead – A structure above the roof of any part of a building enclosing a stairway, tank, elevator machinery or ventilating apparatus, or such part of a shaft as extends above the roof; a sloping door or doors affording entrance to a cellar from outside a building.

Bull-Nose – A rounded corner used to obtain a decorative and finished appearance.

Burl – A distortion of wood grain, usually caused by abnormal growth due to injury of the tree.

Butt-Joint – Any joint made by fastening two members together without overlapping.