Glossary of Industry Terms




A term used when a wall surface has developed a slide.

Salt glaze

A glaze produced by the reaction, at elevated temperature, between the ceramic body surface and salt fumes produced in the kiln atmosphere. (ASTM C 242).


The method of obtaining tile for testing from an agreed-upon lot.


A method of scarifying the surface of concrete or masonry to provide a bondable surface. Compressed air is used to propel a stream of wet or dry sand onto the surface.

Sand holes

Tiny pits in the surface of the tile. Sandblast. A system of cutting or abrading a surface such as concrete by a stream of sand ejected from a nozzle at high speed by compressed air; often used for cleanup of horizontal construction joints or for exposure of aggregate in architectural concrete.

Sander-grinder (Cutting tool)

In addition to sander and grinder attachment both uninstalled and installed tile. The cutting is done dry.


A portable source of heat, customarily oilburning, used ‘to heat an enclosure around or over newly placed concrete to prevent the concrete from freezing.

Saw cut

A cut in hardened concrete utilizing diamond or silicone-carbide blades or discs.

Sawed joint

A joint cut in hardened concrete, generally not to the full depth of the member, by means of special equipment.


A temporary structure for the support of deck forms, cartways, or workmen, or a combination of these such as an elevated platform for supporting workmen, tools, and materials; adjustable metal scaffolding is frequently adapted for shoring in concrete work.


A piece of thin sheet metal with teeth or serrations cut in the edge. It is used to roughen fresh mortar surfaces to achieve a good bond for the tile. A scarifier also can be used to roughen the surface of concrete. (TCA)
Scarred faces. Surface blemishes caused by scraping or other marring of the tile.


A mixture of portland cement, sand, and water.

Scratch coat

The first coat of plaster or stucco applied to a surface in three-coat work; usually cross-raked or scratched to form a mechanical key with the brown coat.


Tiles that have surface scratches (usually glazed wall tile) caused from sand, tools or rough handling.


Any serrated or sharply tined object that is used to roughen the surface of one coat of mortar to provide a mechanical key for the next coat. See also Scarifier.


The application of a scratch coat and its combing with a scratcher.


To strike off mortar laying above the desired plane or shape.

Screed guide

Firmly established grade strips or side forms for unformed concrete which will guide the strikeoff in producing the desired plane or shape.

Sculptured tile

Tile Nvith a decorative design of high and low areas molded into the finished face. ((:TI) Sealant. An elastomeric material that is used to fill and seal the expansion joint. This material prevents the passage of moisture and allows horizontal and lateral movement at the expansion joint.

Sealing compound

See Joint sealant.

Secondary clay (sedimentary clay)

A clay which has been geologically transported From its place of formation. (ASTM C 242).

Second grade ceramic tile

Ceramic tile with appearance defects not affecting wearing or sanitary qualities.


Metal lath or welded wire fabric formed in the manufacturing process to include means by which the material is held away from the supporting surface, thus creating a space for “keying” of the insulating concrete, plaster, or stucco.

Self-spacing tile

Tile with lugs, spacers, or protuberances on the sides. These devices automatically space the tile for the grout joints. (SS-T-308b)

Semi-mat glaze

A colorless or colored glaze having moderate gloss. (ASTM C 242).


A trade term designating semivitreous dinnerware. (ASTM C 242).


-3 percent to 7 percent water absorption. Set. The condition reached by a cement paste, mortar, or concrete when it has lost plasticity to an arbitrary degree, usually measured in terms of resistance to penetration or deformation; initial set refers to first stiffening; final set refers to attainment of significant rigidity; also, strain remaining after removal of stress. Setting bed. The layer of mortar cm which the tile is set. Tile final coat of mortar oil a wall or cciliu- also may he called a setting bed. (TCA)

Setting time

See Initial setting time and Final setting time.


The gradation of color.

Sharp sand

Coarse sand of which the particles are of angular shape.


A wall portion of a structural frame intended to resist lateral forces, such as earthquake, wind, and blast, acting in or parallel to the plane of the wall.

Shelf life

Maximum interval during which a material may be stored and remain in a usable condition.

Ship and galley tile

A special quarry tile having an indented pattern on the face of the tilt to produce ;in antislip effect. (ASTM C 242).

Shivering (peeling)

The splintering which occurs in fired glazes or other ceramic coatings due to critical compressive stress. (ASTM C 242).

Shore A hardness

The reading of a material’s hardness on a durometer, the scale of which is 0-100, used on elastomers as polyacrylic esters and natural rubber. Consists of a pinpoint depression into the material, the material being at least 100 mils thick. A Shore A reading of 80 equals a Shore D reading of 30.

Shore D hardness

The reading of a material’s hardness on a durometer similar to the Shore A durometer, the scale of which is 0-100, used on rigid and semi-rigid materials such as polystyrene. Consists of a pinpoint depression into the material.Both the Shore A and Shore D instruments are made by the Shore Instrument Manufacturing Company, Inc., Jamaica, New York. Shower floor waterproof membrane. See Waterproof membrane.

Shower pan

Terminology used in sonic areas for Waterproof membrane. (CTI)

Shower receptor

The floor and side walls of the shower up to and including the curb of the shower. (CTI) Shower receptor liner or lining. Terminology used in some areas for Waterproof membrane.

(CTn) Shrinkage

The decrease in volume, or contraction, of a material by the escape of any volatile substance, or by a chemical or physical change in the material.

Shrinkage crack

Crack due to restraint of shrinkage.

Shrinkage cracking

Cracking of a structure or member due to failure in tension caused by external or internal restraints as reduction in moisture content develops, or as carbonation occurs, or both.

Silica (S’OQ)

The common oxide of silicon usually found naturally as quartz or in complex combination with other elements as silicates. Various polymorphs and natural occurrences of silica include cristobalite, tridymite, cryptocrystalline chert, flint, chalcedony, and hydrated opal.

Skid resistance

A measure of the frictional characteristics of a surface.

Skim coat

See Bond coat.


A fresh tile wall that has buckled or sagged. This condition may be caused by excessive mortar, insufficient lime in the mortar, or excessive moisture in the scratch coat. A slide also may result if the surface is slick or the mortar is too soft.

Slip coating

A ceramic material or mixture other than a glaze. applied to a ceramic body and fired to the maturity required to develop specified characteristics. (ASTM C 242).

Slip glaze

A glaze consisting primarily of a readily fusible clay or silt. (ASTM C 242).

Slip process

See Process, wet.

Slip-resistant tile

Tile having greater slip-resistant characteristics clue to an abrasive admixture, abrasive particles in the surface or grooves or patterns in the surface.

Slip (slurry)

A suspension of ceramic material in liquid. (ASTM C 242).

Slot cut

Description of a tile that has been cut to fit around pipes or switch boxes. This tile is usually in the shape of the letter lI or the letter L.


A measure of consistency of freshly mixed concrete, mortar, or stucco equal to the subsidence measured.

Slump cone

A mold in the form of the lateral surface of the frustum of a cone with a base diameter of 8 in. (203 mm), top diameter 4 in. (102 mm), and height 12 in. (305 mm), used to fabricate a specimen of freshly mixed concrete for the slump test; a cone 6 in. (152 mm) high is used for tests of freshly mixed mortar and stucco.

Slump test

The procedure for measuring slump. Slurry. A mixture of water and any finely divided insoluble material, such as portland cement, slag, or clay in suspension.

Slush coat

A pure coat of a very soft consistency. This also is called a slurry coat.

(noun). A specific batch or lot of frit.
(verb). The act of melting a batch of frit. (ASTM C 21).


A furnace in which the raw materials of a frit batch are melted. (ASTM C 21)
Soaping tile. The method of applying a soapy film to newly tiled .walls to protect them from paint and plaster during construction. (TCA)


The underside of a part or member of a structure, such as a beam, stairway, or arch.


A generic term for unconsolidated natural surface material above bedrock.

Soldier course

Oblong tile laid with the long side vertical and all joints in alignment.

Specific gravity

The ratio of the weight of any volume of a mass or substance to the weight of an equal volume of water at a given temperature. The specific gravity of a substance times the density of water equals the density of the substance.

Special-purpose tile

A tile, either glared or unglazed, made to meet or to have specific physical design or appearance characteristics such as size, thickness, shape, color, or decoration; keys or lugs on backs or sides; special resistance to staining, frost, alkalies, acids, thermal shock, physical impact, high coefficient of friction, or electrical properties. (ASTM C 242).

Specific gravity

The ratio of the weight of any volume of a mass or substance to the weight of an equal volume of water at a given temperature. The specific gravity of a substance times the density of water equals the density of the substance.


Any dark dots on the tile less than 1/64 inch in diameter, and noticeable at a distance of more than three feet.


The dry ingredients remaining after evaporation of all volatile solvent or water. Not a fluid and not flowable.

Solid casting

See Casting, solid.

Soluble (adj.)

Describes the property of a substance to dissolve in another and form a solution, e.g., sugar is soluble in water.
Solution. The process by which a substance (solid, liquid, or gas) is homogeneously mixed with a liquid, called the solvent, and the mixture being incapable of mechanical separation into its components. Alloys and amalgams are solutions of metals in metal; brines are solutions of a salt in water; syrups are solutions of sugars in water. Solution should not be confused or used interchangeably with such terms as dispersion, suspension or emulsion.


In a solution, that substance which dissolves another is called the solvent.
Solvent is also a common term for many liquids which are commonly used in making solutions, e.g., organic solvents, petroleum solvents, etc. Also used for thinning down a fluid, and for cleaning purposes.


T-shaped and Y-shaped, they are used in installation to separate tile on walls and floors. They are manufactured in various thicknesses from’hs” to 1/2′.

Spacing; mix

A dry or dampened mixture of one part Portland cement and one part extra-fine sand. This inix is used as a filler in the joints of mounted ceramic mosaic tiles to keep them evenly spaced during installation.


A fragment, usually in the shape of a flake, detached from a larger mass by a blow, by the action of weather, by pressure, or by expansion within the larger mass.


That part of a wall between the head of a %,.-indow and the soil of the window above it.


A glaze defect of the pinhole type developed in the decorating kiln, due to evolution of minute gas bubbles from body or glaze. (ASTM C 242).

Splash walls

The walls of a tile drainhoard or bathtub.

Split L cut

An improper L cut that is made by splitting a tile instead of cutting it.

Spodumene (alpha spodumene)

A lithium mineral of the theoretical composition Li20 – A120a – 4Si02 (monoclinic crystallization) which on heating inverts to beta spodumene, a form having very low nil thermal expansion. (ASTM C 21)


Any dark dots on the face of the tile more than 1/64 inch in diameter.

Spread, noun

The quantity of adhesive per unit area applied to an adherent, usually expressed in pounds of adhesive per thousand square feet of area. (1) Single Spread refers to application of adhesive to only one adherent. (2) Double Spread refers to application of adhesive to both adherents.


The ability to remain unchanged; equilibrium, steady, constant. Ability to restore to original condition after being disturbed by some force.

Stacking tile

A method of installation whereby glazed tiles are placed on the wall so that they are in direct contact with the adjacent tiles. The width of the joints is not maintained by the use of string or other ar1cans. The tiles may he set with either straight or broken joints. (TCA)


Discoloration caused by a foreign matter chemically affecting the material itself.

Standard grade ceramic tile

Highest grade of all types of ceramic tile.

Steam curing

Curing of concrete or mortar in water vapor at atmospheric or higher pressures and at temperatures between about 100 and 420 F (40 and 215 C). (See also Autoclave curing).

Steatite porcelain

A vitreous ceramic whiteware for technical application in which magnesium metasilicate (MgO – SiO,) is the essential crystalline phase. (ASTM C 242).

Steatite tale

Massive talc or the pulverized product. thereof having the general formula 3 MgO – 4SiO, H2O. (ASTM C 242).

Steatite whiteware

Any ceramic whiteware in which magnesium metasilicate (MgO – SiO,) is the essential crystalline phase. (ASTM C 242).

Steel square

The steel square is one of the most important tilesetting tools. The large arm of the square is 2″ wide and 24″ long and is called the body or blade. The smaller arm is at a 90-degree angle to the blade and is 1’/.,” wide and 16″ long; it is called the tongue. The point where the outside edges of the blade and tongue join is called the heel. The surface with the manufacturer’s name is called the face; the opposite surface is called the back.


Use of a Carborundurn stone to eliminate the jagged and flaked edges, due to cutting.


A vitreous or semivitreous ceramic ware of fine texture, made primarily from nonrefractory fire clay. (ASTM C 242).

Storage life

In the period of time during which a packaged adhesive can be stored under specified temperature conditions and remain suitable for use. Sometimes called “shelf life”.

Story pole

See Layout stick.

Straight joint

The usual style of laying tile where all the joints alignment.


A straight piece of lumber that is used to rod mortar and to align tile.


A masonry unit laid with its length horizontal and parallel with the face of a wall or other masonry member.

Striking joints

A process of removing excess grout from the joints by wiping with a sponge or cloth or scraping with a curved instrument. (TCA)

Structural defects

Cracks or laminations in the bodv of the tile which detract from the aesthetic appearances and/or the structural soundness of the tile installation.


The underlying support for the ceramic tile installation.


A cement plaster used for coating exterior walls and other exterior surfaces of buildings. (See also Plaster.)


Vertical member of appropriate size (2×4 to 4×10 in.) (50×100 to 100×250 mm) and spacing (16 to 30 in.) (400 to 750 mm) to support sheathing of concrete forms; also a headed steel device used to anchor steel plates or shapes to concrete members.