Glossary of Industry Terms




A metal grid that is used to properly space and align floor tiles.

Ragging Off

The procedure of spreading damp cheese cloth and pulling it over the tile surface during the tile grouting process in order to clean the tile.

Raked joint

A joint in a masonry wall which has the mortar raked out to a specified depth while it is only slightly hardened.

Rake or rake line

The inclination from a horizontal direction.

Raw glaze

A glaze compounded primarily from raw constituents, that is, containing no prefused materials. (ASTM C 242).


A metallic ox nonmetallic waterprgof support for a shower stall. (TCA)


A trim unit used to reduce the radius of a bullnose or a cove to another radius or to a square. (TCA)

Refractory concrete

Concrete having refractory prop-. erties, and suitable for use at high temperatures (generally about 315 to 1315 C), in which the binding agent is a hydraulic cement.

Reinforced concrete

Concrete containing adequate reinforcement (prestressed or not prestressed) and designed on the assumption that the two materials act together in resisting forces.

Reinforced masonry

Unit masonry in which reinforcement is embedded in such a manner that the two materials act together in resisting forces.

Reinforcement, mesh

See Welded-wire fabric and Welded-wire fabric reinforcement.

Relative humidity

The ratio of the quantity of water vapor actually present to amount present in a saturated atmosphere at a given temperature; expressed as a percentage.

Release agent

Material used to prevent bonding of concrete to a surface. (See also Bond breaker.)


The ending of a small splash wall or a wainscot at right angle to the major wall.

Rockingham ware

A semivitreous ware or earthenware having a brown or mottled brown bright glaze. Originated in England on the estate of the Marquis of Rockingham. (ASTM C 242).


See Floating.

Rod saw

The rod saw is one of the newest tools used in the cutting of tile. It is a steel rod approximately 1/s” in diameter. The rod has tungsten carbide particles embedded in the surface. The rod saw is used to cut circles or irregular curves in tile.

Roughing in

The act of preparing a surface by applying tar paper and metal lath (or wire mesh). Sometimes called wiring.

Rubber spacers

Cross and tee-shaped objects used to space tile on floors or walls. They are manufactured in thicknesses of 1/16″, 1/8″, 1/4″, 3/8″, and 1/2″.

Rubber trowel

The rubber trowel used for grouting is a non-porous synthetic-rubber-faced float that is mounted on an aluminum back with a wood handle. This trowel is used to force material deep into tile joints and to remove excess material for a perfect finish.

Rubbing stone

A Carborundum stone that is used to smooth the rough edges of tile.


A mineral form of titanium oxide (Ti02) (tetragonal crystallization), but usually produced chemically for use in ceramics and other products. (ASTM C 21)