Wall tile

A glazed tile with a body that is suitable for interior use and which is usually nonvitreous, and is not required nor expected to withstand excessive impact or the capillaries.

Warpage

A concave or convex curvature of a tile so that the surface is not perfectly flat.

Water absorption

The ability to take up and retain water. Water-cement ratio. The ratio of the amount of water, exclusive only of that absorbed by the aggregates, to the amount of cement in a concrete or mortar mixture; preferably stated as a decimal by weight.

Water level

The water level is a piece of clear plastic hose 3/8" to 1/2" in diameter and usually about 50' in length. It is filled with water, from which all air must be removed.

Waterproof membrane

A membrane, usually made of built-up roofing, to provide a positive waterproof floor over the substrate, which is to receive a tile installation using a wire reinforced mortar bed. (CTI)

Wearing course

A topping or surface treatment to increase the resistance of a concrete pavement or slab to abrasion.

Weathering

Changes in color, texture, strength, chemical composition or other properties of a natural or artificial material due to the action of the weather.

Welded-wire fabric

A series of longitudinal and transverse wires arranged substantially at right angles to each other and welded together at all points of intersection.

Welded-wire fabric reinforcement

Welded-wire fabric in either sheets or rolls, used to reinforce mortar and concrete.

Well-graded aggregate

Aggregate having a particle size distribution which will produce maximum density, i.e., minimum void space.

Wet areas

Interior or exterior tiled areas subject to periodic or constant wetting. Examples: showers; sunken tubs; pools; exterior walls; roofs; exterior paving and interior floors. (CTI)

Wet pressing

See Pressing, wet. Wet process. See Process, wet.

Wetting

The thorough impregnation of a material by a liquid. The more viscous a fluid, and the higher its surface tension, the more difficult it is for the liquid to "wet" materials. Certain additives, for example, water softeners, reduce surface tension, or viscosity and improve wetting properties, allowing the material to flow out more.

Wetting agent

A substance capable of lowering the surface tension of liquids, facilitating the wetting of solid surfaces and permitting the penetration of liquids into the capillaries.

Whiting

Calcium carbonate powder of high purity. (ASTM C 242).

Wire mesh

See Welded-wire fabric.

Wood float

The wood float is sometimes used in place of the flat trowel for floating mortar. It is good for smoothing small irregularities left on the mortar bed, working the surface of the mortar before troweling on the pure coat, or compacting floor and deck mortar.

Workability

The property of freshly mixed concrete or mortar which determines the ease and homogeneity with which it can be mixed, placed, compacted, and finished.

Wrinkled sheets

Pertaining to ceramic mosaics mounted on paper. Due primarily to rough handling in shipment.