Back wall

The wall facing an observer who is standing at the entrance to a room, shower, or tub shower. Backing. Any material used as a base over which a finished material is to be installed.

Backing off

See Featheredging tile. Angle tile. See under Tile, mounted.

Balanced cuts

Cuts of tile at the perimeter of an area that will not take full tiles. The cuts on opposite sides of such an area shall be the same size. Also the same sized cuts on each side of a miter.

Ball clay

A secondary clay, commonly characterized by the presence of organic matter, high plasticity high dry strength, long vitrification range, and a light color when fired. (ASTM C 242).

Ball milling

A method of grinding and mixture material, with or without liquid, in a rotating cylinder or conical mill partially filled with grinding media such as balls or pebbles. (ASTM C 242).

Bar support

A rigid device used to support or hold reinforcing bars in proper position to prevent displacement before or during concrete placement.

Basalt ware

A black unglazed vitreous ceramic ware having the appearance of basalt rock. (ASTM C 242). Base. One or more rows of tile installed above the floor. See Cove.

Basis for acceptance

The method of determining whether a lot of ceramic tile is acceptable under these specifications.

Batch mixer

A machine which mixes batches of concrete or mortar in contrast to a continuous mixer.

Batch plant

An operating installation of equipment including batchers and mixers as required for batching or for batching and mixing concrete materials; also called mixing plant when equipment is included.

Beating block

A wooden block used to embed tiles in a flat plane. The method used is called beating in.

Belleek china

A highly translucent whiteware composed of a body containing a significant amount of frit and normally having a luster glaze. (Produced commercially at Belleek, Ireland.) (ASTM C 242).

Bench mark

Permanent reference point or mark.

Bentonite

A clay composed principally of minerals of the montmorillonoid group, charactersized by high absorption and very large volume change with wetting or drying.

Beryllium oxide (berylla) (BeO)

An inorganic material of exceptionally high thermal conductivity which is toxic in the powder form.

Biscuit chips

Glazed-over chips on the edge or corner of the body of a tile.

Biscuit cracks

Any fractures in the body of a tile visible both on face and back.

Bisque fire

See Fire, bisque.

Blaine fineness

The fineness of powdered materials such as cement and pozzolans, expressed as surface area usually in square centimeters per gram, determined by the Blaine apparatus.

Bleb

A small blister or bubble.

Bleeding

The autogenous flow of mixing water within, or its emergence from newly placed concrete or mortar; caused by the settlement of the solid materials within the mass; also called water gain.

Blend

To mix or make homogeneous.

Blistering

The development during firing of enclosed or broken macroscopic vesicles or bubbles in a body, or in a glaze or other coating. (ASTM C 242).

Block angle

A square of tile specially made for changing direction of the trim.

Bloom

A visible exudation or efflorescence on the surface.

Blots

Green marks or stains on the face of a tile.

Blunging

The wet process of blending, or suspending ceramic material in liquid by agitation. (ASTM C 242). The structural portion of a ceramic article. This term also refers to the material or mixture from which the article is made. (ASTM C 242).

Bond

The adherence of one material to another. Effective bonds must be achieved between the mortar and scratch coat, between the tile and mortar, and between the adhesive and backing.

Bond breaker

A material used to prevent adhesion of newly placed concrete and the substrate.

Bond coat

A material used between the back of the tile and the prepared surface. Suitable bond coats include pure portland cement, Dry-Set portland cement mortar, latex-type portland cement mortar, organic adhesive, and the like.

Bonding agent

A substance applied to a suitable substrate to create a bond between it and a succeeding layer as between a subsurface and a terrazzo topping or a succeeding plaster application.

Bone ash

Calcined bone consisting essentially of calcium phosphate. (ASTM C 242).

Bone china

A translucent china made from a ceramic whiteware body composition containing a minimum of 25 percent bone ash. (ASTM C 242).

Brick trowel

The brick trowel is larger than the buttering trowel. The most popular size used by tilesetters is 5" wide and 11" long. It is used when any preparatory brick work has to be done. Some tilesetters use it for quarry and terra cotta tilework. Its greater surface and weight are advantageous in the buttering and tapping in of the larger tiles.

Bridge

A straightedge used as a starting line for the laying of tile. The straightedge can be blocked up to support tile over an opening.

Bridge deck

The slab or other structure forming the travel surface of a bridge.

Bright glaze

colorless or colored ceramic glaze having high gloss. (ASTM C 242).

Broom finish

The surface texture obtained by stroking a broom over freshly placed concrete. (See also Brushed surface.)

Brown coat

The second coat in three-coat plaster application.

Brushed surface

A sandy texture obtained by brushing the surface of freshly placed or slightly hardened concrete with a stiff brush for architectural effect or, in pavements, to increase skid resistance. (See also Broom finish.)

Building official

The official charged with administration and enforcement of the applicable building code, or his duly authorized representative.

Bulking

Increase in the bulk volume of a quantity of sand in a moist condition over the volume of the same quantity dry or completely inundated.

Bulking curve

Graph of change in volume of a quantity of sand due to change in moisture content.

Bulking factor

Ratio of the volume of moist sand to the volume of the sand when dry.

Bull float

A tool comprising a large, flat, rectangular piece of wood, aluminum, or magnesium usually 8 in. (20 cm) wide and 42 to 60 in. (100 to 150 cm) long, and a handle 4 to 16 ft. (1 to 5 cm) in length used to smooth unformed surfaces of freshly placed concrete.

Bullnose

A trim tile with a convex radius on one edge. This tile is used for finishing the top of a wainscot or for turning an outside corner.

Bullnose corner

A type of bullnose trim with a convex radius on two adjacent edges.

Bundled bars

A group of not more than four parallel reinforcing bars in contact with each other, usually tied together.

Burlap

A coarse fabric of jute, hemp, or less commonly, flax, for use as a water-retaining covering in curing concrete surfaces; also called Hessian.

Bushhammer

A hammer that has a rectangular head with serrated or jagged faces. The bushhammer is used for roughing concrete to provide a bond for masonry. Butterfly. A slang term for inside corner angles for trim shapes such as AB 106, AF 105, AF 200, AK 106, and AU 106.

Butt joint

A plain square joint between two members.

Buttering

The spreading of a bond coat (followed by a mortar coat, a thin-setting bed mortar, or an organc adhesive) to the backs of ceramic tile just before the tile is placed.

Buttering trowel

The blade of the buttering trowel is 41/2' wide and 7" long. It is used in buttering pure cement to tile, a method commonly used in the eastern states. The trowel is more efficient than the pointer for working on the larger and heavier tiles because more weight can be placed on it.

Buttonback Tile

Tile that have projections on the bondable side. Many of, these projections are round and therefore the term buttonback. Some projections are quite thick and can also be other shapes, such as square.