Glossary of Tile Terminology
The Most Comprehensive Glossary of Ceramic & Stone Tile Terminology Online
Although this may be the most comprehensive list of tile terminology you can find, it is by no means complete. Glossaries and tile articles from around the Internet have been researched to compile this list and it is an ongoing project. If you know a term related to ceramic or stone tile that is not listed here, please use the comment form to add it. In return, we will link to your professional flooring related website. You might also spot a mistake in our glossary, or feel additional information should be provided. Please use the comment form below to inform us so we can continue to make this the finest place for flooring information on the web.
ABSORPTION: The relationship of the weight of water absorbed to the weight of the dry specimen, expressed in percentages.
ACCELERATORS: Materials used to speed up the setting of mortar.
ACOUSTICAL SEALANT: A sealant with acoustical properties used to seal the joints in the construction of sound rated ceramic tile installations.
ACRYLIC: A general class of resinous polymers used as additives for thin-set mortar and grout (see PORTLAND CEMENT MORTAR or GROUT).
ADHESIVE: A product used for bonding tile to a surface.
ADDITIVE or ADMIXTURE: A material other than water, aggregates, or hydraulic cement, used as an ingredient of grout or mortar and which is added immediately before or during its mixing.
AGGLOMERATED PRODUCT: A man made stone product generally consisting of either crushed natural marble, natural granite or quartz chips with a matrix of resins and mineral pigments. The product is available in assorted tile sizes as well as large slabs.
AGGREGATE: Granular material such as sand, gravel, or crushed stone, used with a cementing medium to form a hydraulic-cement or mortar.
ANGLED TILES: Trim tiles mitered along one or two edges, used in corner and countertop installations (see JOLLY).
ANGOLO: A decorative corner piece used in floor installations. Often used in conjunction with a fascia to create a “rug” border effect. Some angolos may be used together to create a small ROSONE.
APRON: Trim or facing on the side or in front of a countertop, table edge or windowsill.
ASTM: American Society for Testing & Materials. Most ceramic tile manufacturers use a rating system based on or supported by this group.
BACK-BUTTER: The spreading of a bond coat to the back of a ceramic tile immediately before the tile is installed.
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 ceramic tile is to be installed (see SUBSTRATE).
BALANCED CUTS: Cuts of tile at the perimeter of an area which will not take full tiles. Also the same sized cuts on each side of a miter.
BASE: One or more rows of tile installed above the floor (see COVE BASE).
BATTISCOPA: The Italian term for a bull nose trim piece.
BEATING BLOCK: A wooden block used to embed tiles in a flat plane. The method is called “beating in.”
BENCH MARK: Permanent reference point or mark.
BIOCUTTURA TILE: Ceramic tiles fired in a kiln at temperatures ~ 2,000 degrees Fahrenheit. These tiles are first fired after the green tile dries and then again after glaze is applied.
BISQUE: The larger of a tile’s two layers. The top layer is called the glaze the bottom layer is the bisque. Tiles are manufactured using varying bisque recipes. The recipe of the bisque and the temperature used when kiln-firing the tile will determine the moisture absorbency of the tile body (bisque).
BISQUE CRACKS: Any fractures in the body of a tile visible both on the face and back.
BODY: The term refers to the structural portion of a ceramic product and to the material or mixture from which it is made.
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 Portland cement mortar, organic adhesive and epoxy mortar or adhesive.
BOND STRENGTH: A bond coat’s ability to resist separating from the tile and setting bed. Measured in pounds per square inch (psi).
BORDER: A strip of tile with design, texture or contrasting color that creates a design concept (see FEATURE STRIP).
BOX SCREED: A jig used to apply mortar onto the back side of large-sized ceramic, marble and granite tiles which may vary in thickness, in order to achieve a uniform unit of thickness of the tile and mortar combined.
BRICK PATTERN: Tile is set in a staggered pattern similar to a brick wall (see RUNNING BOND). Any shape tile that is square or rectangular may be set with a brick pattern.
BROKEN JOINT: Ceramic tile installation featuring each row offset (see RUNNING BOND).
BRUSHED FINISH: A finish resulting from treating the stone surface with a coarse wire rotary brush.
BULLNOSE: A trim tile with a convex radius or finished edge on one side. Used for finishing top of wainscot, turning of an outside corner, or floor base.
BUTTERING: The spreading of a bond coat to the back of a ceramic tile immediately before the tile is installed.
BUTTONBACK TILE: Tile that has 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.
CAP: 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.
CAULK: A soft, water resistant plastic material used for sealing joints.
CBU: Cement backer unit. Provides a supportive and water resistant layer between the porous substrate and the mortar and tile applied on top of it.
CEMENT: Refers to Portland cement, which when mixed with sand, gravel, and water forms concrete. Generally, cement is an adhesive; specifically, it is that type of adhesive which sets by virtue of a chemical reaction.
CEMENT GROUT: A cementious mixture of Portland cement, sand or other ingredients and water, to produce a water resistant, uniformly colored material used to fill the joints between tile units.
CEMENTIOUS: Having the properties of cement.
CERAMIC TILE: A product of organic materials extracted from the earth that is shaped into tiles and then fired in kilns at extremely high temperatures.
CHALK LINE: Usually a cotton cord coated with chalk. The cord is pulled taut and snapped to mark a straight line. The chalk line is used to align spots or screeds and to align tiles.
CHEMICAL RESISTANCE: The resistance offered by products to physical or chemical reactions as a result of contact with or immersion in various solvents, acids, alkalis, salts, etc.
CLAY: Natural earthen material, which is the basic raw material of ceramic tiles.
CLEAVAGE MEMBRANES: A membrane that provides a separation and slip-sheet between the mortar setting bed and the backing or base surface.
CLINKER (KLINKER): Red body formed by either the extrusion process or dust pressing. Sometimes referred to as red stoneware. This tile can be glazed or unglazed with a water absorption of 0.7%.
COEFFICIENT OF FRICTION (COF): The Slip resistance of a tile.
COLD JOINT: Any point in concrete construction where a pour was terminated and the surface lost its plasticity before work was continued.
COLORED GROUT: Commercially prepared grout consisting of carefully graded aggregate, Portland cement, water dispersing agents, plasticizers and color fast pigments.
COMPACTION: The process whereby the volume of freshly placed mortar or concrete is reduced to the minimum practical space usually by vibration, centrifugation, tamping or some combination of these; to mold it within forms or molds and around imbedded parts and reinforcement and to eliminate voids other than entrained air.
COMPOSITION TILE: A hard tile surface made from a mixture of chemicals. The finished surface can be the mixture of chemicals or can be marble chips to create a terrazzo finish. The tile is made hard by the set of the chemicals and the products are not fired as they are in ceramic tile.
COMPRESSIVE STRENGTH: A material’s ability to withstand a load measured in psi.
CONDUCTIVE MORTAR: A tile mortar to which specific electrical conductivity is imparted through the use of conductive additives.
CONSTRUCTION JOINT: The surface where two successive layers of concrete meet.
CONTRACTION JOINT: Groove in concrete structure to regulate location of cracking resulting from dimensional change of different parts of a structure.
COPING: The material or units used to form a cap or finish on top of a wall, pier, pilaster or chimney.
CORUNDUM: An abrasive or grit added to a tile glaze in order to increase tile slip-resistance.
COVE: A trim tile unit having one edge with a concave radius. This is used to form a junction between the bottom wall course and the floor or to form an inside corner.
COVE BASE: A trim tile having a concave radius on one edge and a convex radius on the opposite edge. This base is used as the only course of tile above the floor tile.
CRAWLING: A parting and contraction of the glaze on the surface of ceramic ware during drying or firing, which results in unglazed areas bordered by coalesced glaze.
CRAZING: The cracking that occurs in fired glazes or other ceramic coatings due to critical tensile stresses (minute surface cracks).
CURING: Time period that a tile installation setting material must be undisturbed and allowed to set for it to reach full strength.
CUSHION-EDGED TILE: Tile on which the facial edges have a distinct curvature that results in a slightly recessed joint.
DASH COAT: A first coat of mortar sometimes applied to a smooth surface with a whisk broom or fiber brush in such a manner as to provide a good mechanical key for subsequent mortar coats.
DECK-MUD: A mixture of sand, Portland cement and water used to create a suitable floor surface to receive tile. The mixture is mixed to a stiff consistency (is not pourable) then placed on the surface and compacted using a wooden float, then the surface is shaved to a level finish. See also SANDMIX, SHOWER BASE MUD.
DECORATIVE TILE: any tile face with a decoration on the surface.
DEFLECTION: A measure of the rigidity of a suspended wood floor structure, specifically, the amount of movement between the joists in a particular span of post or column supported joists. The accepted minimum deflection is L/360 for most tile, which is the Length of the supported span divided by 360. Although the failure of tile installations over structures that do not meet the minimum is well known, research has shown that structures much greater than L/360 (L/600 observed) have also failed.
DENSITY: The weight of a tile. As it increases, the amount of moisture that tile can absorb becomes less.
DIAGONAL SET: Tile set at a 45° angle to the floor or wall.
DOLLOP: A small amount (aprox. 1-Tblsp) of cement-based tile adhesive used to apply tiles to walls. A typical wall tile application may use the “Five Dollop Method,” where five equal sized dollops of adhesive are placed uniformly on the back of a tile before placing it on the wall.
DOUBLE FIRED TILE: Ceramic tiles fired in a kiln at temperatures ~ 2,000 degrees Fahrenheit. These tiles are first fired after the green tile dries and then again after glaze is applied.
DOT-MOUNTED TILE: Tile packaged in sheet format and held together by plastic or rubber dots between the joints.
DRY-SET MORTAR: A mixture of Portland cement with sand and additives imparting water retentivity, which is used as a bond coat for setting tile. Normally, when this mortar is used, neither the tile nor the walls have to be soaked during installation. See also UNMODIFIED TILE MORTAR.
DUST-PRESSED TILES: Tiles formed by the dust-pressed method in which the finely milled raw materials are shaped in molds at high pressure before firing (see EXTRUDED TILE).
EFFLORESCENCE: The residue deposited on the surface of a material (usually the grout joint) by crystallization of soluble salts.
ELASTOMERIC: Any of various elastic substances resembling rubber.
EMBOSSED: A decoration in relief or excised on the wear surface.
ENCAUSTIC TILE: Decorated with colored clays inlaid and fired. Also colored tile laid in a wall or floor to form a pattern.
EPOXY ADHESIVE: A 2-part adhesive system employing epoxy hardener and resin for bonding ceramic or stone.
EPOXY GROUT: A 2-part system employing epoxy resin and epoxy hardener to fill the joints between tiles. It is generally resistant to chemicals and stains.
EPOXY MORTAR: A system employing epoxy resins and hardener portions, often containing coarse silica filler and which is usually formulated for industrial and commercial installations where chemical resistance is of great importance.
EPOXY RESIN: An epoxy composition used as a chemical resistant setting adhesive or chemical resistant grout.
ESTIMATE: Projected cost of materials and labor for a construction project or portion of a project.
EXPANSION JOINT: A joint through the tile, mortar and reinforcing wire down to the substrate.
EXTRUDED TILE: A process in which clay material is forced through a mold for the desired shape versus pressing the tile.
FAN or FANNING: Spacing tile joints to widen certain areas so they will conform to a section that is not parallel.
FASCIA: A decorative piece used in floor installations. Often used in conjunction with an ANGOLO to create a “rug” border effect.
FAT-MUD: Similar to DECK-MUD, but fat-mud also contains lime, in addition to Portland cement and sand, mixed to a stiff consistency (not pourable). Lime in the mixture is required for vertical surfaces such as curbs, dams and walls to prevent SAG. See also MORTAR MIX.
FEATURE STRIP: Narrow strip of tile with design, texture or contrasting color that creates a design concept (see BORDER).
FIELD TILE: The primary, uncut tile used to cover a wall or floor.
FIRING: The fifth step in the process of manufacturing ceramic tile. Tiles are fired in a kiln at temperatures ~ 2,000 degrees Fahrenheit.
FLAT TROWEL: This is used in conjunction with the HAWK for transferring mortar from the mortarboard to the wall or to other vertical surfaces. It is also used for spreading CEMENT on the finished FLOAT COAT. The flat trowel also is used for spreading mortar on floor surfaces before tiles are set.
FLOAT COAT: The final mortar coat over which the neat coat, pure coat or skim coat is applied.
FLOAT STRIP: A strip of wood about 1/4 inch thick and 1-1/4 inches wide. It is used as a guide to align mortar surfaces.
FLOATING: A method of using a straightedge to align mortar with float strips or screeds. Specialists use this technique when they are setting glass mosaic murals.
FLOOR TILE: Ceramic tile or natural stone tile durable enough to withstand traffic and abrasion.
FORMELLA: Square tile of classic style with antique glazed or bas-relief decoration.
FRIT: A glass derivative that is applied to ceramic tile as part of a glaze liquid, along with colored dyes, by a high pressure spray or is poured directly onto the tile.
FROST RESISTANT: Vitreous tile that absorbs .5% to 3% water.
FROST PROOF: Tile that is impervious to freezing and absorbs 0% to 0.5% water. Strongest tile for outdoor use.
FURAN GROUT: An intimate mixture of a Furan resin, selected fillers and an acid catalyst. Fillers are generally carbon, silica or combination thereof into which the acid catalyst, or setting agent, may be incorporated. When combined, the components form a trowelable material for buttering or pointing tile.
FURAN RESIN: A chemical resistant acid catalyzed condensation reaction product from furfural alcohol, furfural or combinations thereof.
FURRING: Stripping used to build out a surface such as a studded wall. Strips of suitable size are added to the studs to accommodate vent pipes, shower pans, tubs or other fixtures.
GLASS MESH MORTAR UNIT: A backer board designed for use with ceramic tile in wet areas. It can be used in place of metal lath, Portland cement scratch coat and mortar bed (see CBU).
GLAZED TILE: Tile with an impervious facial finish composed of gaseous ceramic materials fused to the surface of the tile.
GRADE: A predetermined degree of slope that a finished floor should have.
GRADES: Grades of tile recognized in ANSI standard specifications for ceramic tile.
GRANITE: Natural stone more dense than marble. Granite is molten lava that never rose above the surface of the earth. It is extremely durable and holds a polish. Available in polished, honed or flamed (rough) surfaces.
GROUT: A cementitious or other type material used for filling joints between tiles.
GROUTING: The process of filling tile joints with grout.
GROUT SAW: Tool with a saw-toothed carbide steel blade used to remove old grout.
GYPCRETE: Proprietary lite-weight gypsum floor underlayment product, delivering enhanced resistance to surface abrasions and fast drying time. It is not a suitable base for ceramic tile. Special steps must be taken when installing ceramic or stone tile over these lite-weight underlayment products.
HARD SCREED: A mortar screed that has become firm.
HORIZONTAL BROKEN JOINTS: A style of laying tile with each course offset one-half its length.
HOT-MOPPED PAN: A type of shower pan made of alternating layers of hot asphalt and tarpaper.
IMPERVIOUS TILE: Tile with water absorption of 0.5 percent or less.
IN/OUT CORNERS: Trim tile for turning a right-angle inside or outside a wall corner.
INSERT or INSERTO: A decorative tile that coordinates with a field tile and is the same size (e.g. if a field tile is 4″ x 4″, an insert that coordinates is also 4″ x 4″, but is decorative).
IRIDESCENT BILES: Tiles decorated with a lustrous glaze that contains many seemingly changing colors.
ISO: International Standards Organization, a worldwide federation of national standards bodies. ISO/TC 189 “Ceramic Tiles” has drafted international standards for ceramic tiles. ISO Standards unify product standards and testing methods for ceramic tiles worldwide.
ISOLATION JOINT: A separation between adjoining parts of a vertical concrete structure designed to allow for relative movement in three directions.
ISOLATION MEMRANE: Isolation membranes are used to separate a tile installation from its substrate and provide the flexibility necessary to isolate the tile installation from the existing supporting factor.
JOLLY: Trim tiles mitered along one or two edges, used in corner and countertop installations (see ANGLED TILES).
KLINKER (CLINKER): Red body formed by either the extrusion process or dust pressing. Sometimes referred to as red stoneware. This tile can be glazed or unglazed with a water absorption of 0.7%.
L-CUT: A piece of tile cut or shaped to the letter “L”.
LAITANCE: A layer of weak and non-durable material containing cement and fines from aggregates, brought by bleeding water to the top of over-wet concrete, the amount of which is generally increased by overworking or over manipulating concrete at the surface by improper finishing or by job traffic.
LAP JOINT: A method of overlapping adjacent edge areas of two adherents to provide facing surfaces which can be joined with an adhesive.
LAPPATO: Tile finish also known as “Semi-Polished.”
LATEX: A water emulsion of a synthetic rubber or plastic obtained by polymerization and used especially in coatings and adhesives.
LATEX-PORTLAND CEMENT GROUT: Combines Portland cement grout with a special latex additive.
LATEX-PORTLAND CEMENT MORTAR: A mixture of Portland cement, sand and a special latex additive that is used as a bond coat for setting tile.
LATH: Metal mesh which acts as a backing or reinforcing agent for the scratch coat or mortar.
LAYOUT LINES: Lines chalked on a substrate to guide in accurately setting tile.
LAYOUT STICK: A long strip of wood marked at the appropriate joint intervals for the tile to be used. It is used to check the length, width or height of the tile work. Common names for this item are “idiot stick” or “story pole.”
LEACHING: A condition where liquids ooze out of the joint between ceramic tile veneer, regardless if the veneer is grouted or not, and runs down over the tile.
LEG: A tile wall running alongside a bathtub or abutment. This term is sometimes used to describe a narrow strip of tile floor.
LIMESTONE: Sedimentary stone that could have fossils or shells. Usually comes with a honed (matte) finish. Not a wide variety of color; stones have little variety from piece to piece.
LINEAR SHOWER FLOOR DRAIN: Rather than traditional center shower drains that need four slopes and small tiles, the Linear Drain uses a single slope which allows the use of larger format tile. This drain can be installed at the exit of the shower for barrier-free showers.
LIPPAGE: In finished installation, the condition where one edge of a tile is higher than an adjacent tile. May be unavoidable even for tiles that are within the tolerances of dimensional standards, seen especially in very large format tiles.
LISTELLO/LISTEL: Adopted Italian term for decorative border tile, primarily for walls.
LUGGED TILE or LUGS: Protuberances attached to tiles to maintain even spacing for grout lines.
MAJOLICA: Tiles composed of raw materials that produce a yellow-pink body of relatively high water absorption level.
MARBLE TILE: Marble, a natural stone, cut into floor and wall tiles. Available in various finishes; including polished, honed and split face.
MASTER GRADE CERTIFICATE: A certificate which states that the tile listed in the shipment and described on the certificate are made in accordance with ANSI A137.1.
MASTIC: Tile adhesive.
MATTE GLAZE: A glaze that produces a non-shiny finish.
MEMBRANE: A membrane is used to waterproof walls and floors and comes in both sheet and liquid forms. Sheet membranes are applied using thinset mortar while liquid membranes are applied using a paint brush, paint roller, or notched trowel. See also ISOLATION MEMBRANE.
MEXICAN PAVERS: Terracotta-like tile, used mainly for floors, and handmade. They vary in color, texture and appearance, from tile to tile and within each tile. Available in squares up to 12 inches, and in various shapes, these tiles are coated with various types of sealers because of their soft adsorptive characteristics.
MITERED: To cut on an angle to meet on an edge or corner (similar to picture frame moldings or ceiling cove molding).
MODIFIED THINSET: comes with all the necessary additives in the bag and you add only water. There are a variety of modified thinsets with different combinations and qualities of additives, all mixed with Portland cement. See also THINSET and UNMODIFIED THINSET.
MOH’S SCALE: Scale used to express the measure of a materials hardness.
MOISTURE ABSORPTION: As the weight or the density of a tile increases, it becomes a stronger tile and absorbs less moisture.
MONOCOTTURA: A method of producing tile by a single firing, in which body and glazes are fired in kilns at temperatures over 2000 degrees (see SINGLE-FIRED TILES).
MORTAR BED: The layer of mortar on which tile is set. The final coat of mortar on a wall, floor or ceiling is called a mortar bed.
MORTAR MIX: Pre-mixed FAT-MUD, just add water.
MOSAICS: Ceramic, porcelain, glass, metal or stone tile mounted on mesh for ease of installation. May come in squares, octagons, hexagons or random shapes.
MOUNTED TILES: tiles assembled into units or sheets by the manufacturer for easier installation. Back and edge mounted tiles are bonded to material (mesh, paper, resin or other) that becomes part of the installation. Face mounted tiles are bonded to a material that is removed prior to grouting.
MUD: A slang term for mortar and other products. See also DECK-MUD, FAT-MUD, MODIFIED THINSET, MORTAR MIX, SANDMIX, THINSET and UNMODIFIED THINSET.
NEAT CEMENT: Portland cement mixed with water to a desired creamy consistency (see PURE COAT).
NOMINAL SIZES: The approximate facial size or thickness of tile, expressed in inches or fractions of an inch.
NON-VITREOUS TILE: Tile with water absorption of more than 7.0 percent.
NOTCHED TROWEL: A trowel with a serrated or notched edge. It is used for the application of a gauged amount of tile mortar or adhesive in ridges of a specific thickness.
OPEN TIME: The period of time during which the bond coat retains its ability to adhere to the tile and bond the tile to the substrate.
ORGANIC ADHESIVE: A prepared organic material, ready to use with no further addition of liquid or powder, which cures or sets by evaporation.
OUT CORNER: A trim piece with two connecting edges bull-nosed.
PAN LINER: A vinyl sheet product used to waterproof a shower floor. The pan-liner is placed over the PRE-SLOPE and up walls a minimum height of three inches above the top of the shower curb. The pan-liner is used with a “clamping” shower floor drain fastened to the floor drain. An additional application of cement is then placed over the pan-liner.
PAPER AND WIRE: Tarpaper and wire mesh (or metal lath) that are used as a backing for the installation of tile.
PAVERS: Unglazed porcelain or natural clay tile formed by the dust-pressed method and similar to ceramic mosaics in composition and physical properties, but relatively thicker, with 6 inch square or more surface area.
P.E.I.: Porcelain Enamel Institute, responsible for research, testing and analysis of ceramic materials in the United States. PEI (I thru IV) is only applicable in terms of glazed ceramic and porcelain tiles and applies only to the surface of the tile.
PENCIL ROD: Reinforcing rod with a diameter of no greater than 1/4 inch.
PERM/PERM RATING: A unit of permeance or “water vapor transmission” given a certain differential in partial pressures on either side of a material or membrane.
PINHOLES: Imperfections in the surface of a ceramic body or glaze, or in the surface of a grout.
PLASTER: A cementitious material or combination of cementitious material and aggregate that, when mixed with a suitable amount of water, forms a plastic mass or paste which when applied to a surface, adheres to it and subsequently hardens, preserving in a rigid state the form or texture imposed during the period of plasticity; also the placed and hardened mixture.
PLUMB: Perpendicular to a true level.
PLUMB SCRATCH: An additional scratch coat that has been applied to obtain a uniform setting bed on a plumb vertical plane.
POINTING TROWEL: This versatile tool comes in sizes ranging from 4 to 6 inches in length. It is used for straightening tiles on walls and floors, marking floated surfaces, filling small depressions on float coats, buttering tiles and trim work, and placing mortar in areas that are too small for the flat trowel. The butt of the handle is used for tapping in tiles that are not on a true plane with the rest of the tile work.
PORCELAIN TILE: Characterized by a dense and impervious body generally made of the dust-pressed method.
PORTLAND CEMENT: Type of hydraulic cement often used in tile installation.
POT LIFE: The period of time during which a material maintains its workable properties after it has been mixed.
PREFLOAT: The term used to describe mortar that has been placed and allowed to harden prior to bonding tile to it with thin-set materials.
PRE-SLOPE: The first layer of cement installed to a shower floor when using a PAN LINER. The pre-slope consists of sand, Portland cement, and water, installed so it slopes to the floor drain weep-holes prior to the installation of a shower pan liner product.
PSI: Pounds per square inch.
PURE COAT: Neat cement applies to the mortar bed.
QUARRY TILE: Slang term often used for 6×6 impervious unglazed tile.
QUARTER-ROUND or BEAD: A narrow, convexly curved piece designed to create continuity where 90 degree angles occur.
RACK: A metal grid that is used to properly space and align tiles.
RECTIFIED TILE: These are first baked in sheets, then cut to size after, which is why it can be calibrated to exact specifications. Rectified tile can be installed with joints as small as 1/16″.
RAKE or RAKE LINE: The inclination from a horizontal direction.
RECEPTOR: Waterproof base for a shower stall.
REFERENCE LINES: A pair of lines chalked on a substrate that intersect at 90 degree angle and establish the starting point for plotting a grid of layout lines to guide in accurately setting tile.
RETEMPERING: The practice of adding water to mortar to restore workability. Re-tempering MODIFIED THINSET is not recommended.
RETURN: The ending of a small splash wall or wainscot at right angles to the major wall.
ROBINSON TEST: This provides a standardized procedure for evaluating performance of ceramic floor tile installations under conditions similar to actual specific usages. It can be used to make comparisons between customary basic installation methods, to establish the influence of minor changes in a particular installation method, and to judge the merit of proposed novel methods.
RODDING: A method of using a straightedge to align mortar with the float strips or screeds. This technique also is called floating, dragging or pulling.
ROUGHING IN: The act of preparing a surface by applying tar paper and metal lath (or wire mesh). Sometimes called “wiring.”
RUBBER TROWEL: The rubber trowel used for grouting. A nonporous, synthetic rubber-faced float with an aluminum back and wood handle. This trowel is used to force material into tile joints, remove excess grout and form a smooth grout finish.
RUBBING STONE: A Carborundum stone that is used to smooth the rough edges on tile.
RUNNING BOND: Tile is set in a staggered pattern similar to a brick wall (see BRICK PATTERN). Any shape tile that is square or rectangular may be set in a running bond.
SAG: A term used when a wall surface has developed a slide.
SANDBLASTING: 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.
SANDED GROUT: Grout with sand added to provide additional strength to the tile joint. Recommended for tile joints 1/8″ and larger.
SANDMIX: This is pre-mixed DECK-MUD, just add water.
SAND-PORTLAND CEMENT GROUT: A site mixed grout of Portland cement, fine graded sand, lime and water.
SANITARY BASE: A ceramic floor tile trim with a rounded finished top like a bullnose, used to cover up the body of the tile.
SCARIFY: A mechanical means of roughing a surface to obtain a better bond.
SCRATCH COAT: A mixture of Portland cement, sand and water applied as the first coat of mortar on a wall or ceiling. Its surface usually is scratched or roughened so that it will bond properly with subsequent coats of mortar.
SCRATCHER: 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.
SCREED: The mixed cement product being placed on a surface so-as to fill/raise/texture in preparation for the installation/application of finished tiling surface products.
SCREED STRIP: Strips of wood, metal, mortar or other material used as guides on which a straightedge is worked to obtain a true mortar surface.
SCULPTURED TILE: Tile with a decorative design of high and low areas molded into its face.
SEALANT: An elastomeric material used to fill and seal expansion and control joints. This material prevents the passage of moisture and allows the horizontal and lateral movement at the expansion and control joints.
SEALER: A liquid product used to seal (close) the surface pores of tile or grout. It slows the penetration of any spills or unwanted liquids on a surface. Sealers also allow for vapor-transmission from below finished tile and concrete surfaces to promote natural evaporation of moisture.
SELF-SPACING TILE: Tile with lugs, spacers or protuberances on the sides that automatically space the tile for the grout joint. Some tiles are manufactured with the bottom of the tile uniformly wider than the surface of the tile to promote uniform spacing of tiles.
SET-UP TIME: The time adhesive or mortar, spread on a surface takes to cure or harden.
SETTING BED: The layer of mortar on which the tile is set. The final coat of mortar on a wall or ceiling may also be called a setting bed.
SHADE VARIATION: This is inherent in all fired ceramic products. Certain tiles will show greater variation within their dye lots. Typically listed on the back label of each sample with a low, moderate, high or random rating.
SHELF LIFE: The maximum period of time that an item can be stored before it is used.
SHOWER BASE MUD: A mixture of sand, Portland cement, and water used to form a sloped shower base receptor. It is mixed very dry so a handful can be formed into a ball. The mixture is then placed onto the shower PRE-SLOPE, compacted tightly, then shaved with a straightedge to form a ¼” per lineal foot sloping contour to the floor drain.
SHOWER PAN: A waterproof shower floor membrane made from metal, layers of built-up roofing or single or multiple elastomeric membranes.
SHOWER TRAY: A system of providing a pre-made sloping shower floor. Made of plastic and molded with the proper slope for drainage as well as the necessary drain hole. Shower trays are covered with a waterproof membrane to which tile is then directly applied.
SILICONE GROUT: An engineered elastomeric grout system for interior use.
SINGLE-FIRED TILES: Glazed tiles produced by the single-firing method in which the raw tile body and glaze undergo a single pass through the kiln at high temperature (see MONOCTTURA).
SINK ANGLE: Trim shape used on a drainboard at the corners of the kitchen sink. This trim shape, which is AU 106, is also called a “Butterfly.”
SKID RESISTANCE: A measure of the frictional characteristics of a surface.
SKIRTING TILES: Rectangular trim tiles used along baseboard. The length of tile is generally 3 to 4 times the height. Also known as baseboard tiles.
SLAKE: Allowing the mixtures of mortar, thin-set mortar or grout to stand for a brief period of time after ingredients have been thoroughly combined and before the final mixing has occurs to satisfy the thirst of the blended dry products and promote proper melding of the components. Slaking enables the moisture in the mix to penetrate lumps in the dry components, making it easier to complete the mixing procedure.
SLATE TILE: Natural stone material that is known for its dynamic colors and “earthy” appeal. Colors range from grey to purple to black. Slate is used outside as well as inside because of its natural look and wonderful colors.
SLIDE: A fresh tile wall that has sagged. This condition may be caused by excessive mortar, insufficient lime in the mortar or excessive moisture in the mortar. A slide may also result if the surface is slick or if the mortar is too soft.
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 “H” or the letter “L”.
SLURRY COAT: A pure coat of a very soft consistency.
SOLDIER COURSE: Oblong tile laid with the long side vertical and all joints in alignment.
SPACERS: Plastic, rubber, wood or rope used in wall or floor installations to separate tiles. Manufactured spacers are available in thickness’ 1/16 inch to 1/2 inch.
SPACING MIX: A dry or dampened mixture of one part Portland cement and one part extra-fine sand. This mix is used as a filler in the joints of mounted tile.
SPANDREL: That part of a wall between the head of a window and the sill of the window above it.
SPLASH WALLS: The walls of a tile drain board or bathtub.
SPLIT L-CUT: An improper “L” cut that is made by splitting a tile instead of cutting it.
SPOTS: Small pieces of tile placed on a wall or floor surface to align the screeds or setting bed. Spots of casting plaster also may be used.
STACKED SET: Setting a tile in a stacked set means to assemble tiles next to each other with no stagger. Any tile that is square or rectangular may be stacked set.
STANDARD GRADE CERAMIC TILE: Highest grade of all types of ceramic tile.
STATIC COEFFICIENT OF FRICTION (CoF): Slip resistance. The degree of slip resistance presented in a quantitative number that expresses the degree of slip resistance. Slip resistance is evaluated by the horizontal pull method (ASTM C1028). There is no current ANSI requirement a coefficient of friction of 0.5 and above is the recognized industry standard for a slip resistant floor.
STORY POLE: A measuring stick created for a particular tile installation whose unit of measure is the width of a single tile and grout joint rather than inches. This tool gives tile setters a quick, efficient means of determining how many tiles will fit in a given area and where to position layout lines.
STONED: Use of a Carborundum stone to smooth rough edges caused by cutting.
STRAIGHTEDGE: A straight piece of wood or metal that is used to rod mortar and to align tile.
STRAIGHT JOINT: The usual style of laying tile where all the joints are in alignment.
STRAIGHT SET: Tile set square to the wall.
STRETCHER: Trim shapes of tile between trim angles.
STRIKING JOINTS: A process of removing excess grout from the joints by wiping them with a sponge or cloth, or by scraping them with a curved instrument.
STRUCTURAL DEFECTS: Cracks or laminations in the tile body that detract from the aesthetic appearances and/or structural soundness of the installation.
SUBFLOOR: A rough floor – plywood or boards – laid over joists and on which an underlayment or substrate is installed.
SUBSTRATE: The underlying support for ceramic tile installations.
SUBWAY TILE: The shape of a subway tile is rectangular and flat, set with a narrow grout joint and often comes in sizes with a 1:2 ratio (3×6, 4×8). Some subway tiles can have beveled edges for a deeper grout joint. Subway tiles can be stacked set or running bond pattern and installed vertically or horizontally.
TCNA: Tile Council of North America, a trade association representing manufacturers of ceramic tile, installation materials, equipment, raw materials, and other related products. It is recognized for its leadership role in facilitating the development of North American and International industry quality standards to benefit tile consumers. TCNA regularly conducts independent research and product testing, works with regulatory, trade, and other government agencies, offers professional training, and publishes installation guidelines, tile standards, economic reports, and promotional literature.
TERRA COTTA: Hard baked clay-based unglazed or glazed ceramic, where the fired body is porous. This product requires a sealer to prevent staining. Used mainly on interior floors.
THICK-BED MORTAR: A thick layer of mortar (more than 1/2 inch) that is used for leveling.
THINSET: A form of tile adhesive, it comes two ways. Modified and Unmodified, and those two ways also come in grey and white. There are more variations and more coming but this will give you the basic idea. Thinset is a Portland cement type product. See also MODIFIED THINSET and UNMODIFIED THINSET.
THRESHOLD: Raised member of the floor between the doorjambs.
THRICE-FIRED TILES: Decorated, glazed tiles that undergo a third firing after the initial glaze has been applied. This technique is used to obtain special effects or may be used if the material content (e.g. gold) requires it.
THROUGH BODY: Unglazed tiles that are a solid color all the way through and do not have a top layer of glaze.
TIE WIRE: The 18-gauge galvanized wire used for a variety of purposes in construction work.
TILE: A ceramic unit, usually thin in relation to facial area. Made from clay or a mixture of clay and other ceramic material. Has a glazed or an unglazed face. The term is also used for stone used on flooring or walls.
TILE CUTTER: Power or manually operated tool that is one of the most efficient and economic tools in the tile setting trade.
TILE DENSITY: The weight of a tile. As it increases, the amount of moisture that tile can absorb becomes less.
TILE NIPPER: Special pliers that nibble away little pieces of ceramic tile to create small, irregular or curved cuts.
TRAVERTINE TILE: This stone has a similar composition as limestone, but with holes created by hot springs. Colors include beige, red, yellow and brown, with some variation from piece to piece.
3-4-5-TRIANGLE: A triangle with sides in the proportion of 3:4:5, which produces one 90-degree corner. Plotting a 3- 4-5 triangle is a method used to establish a pair of square reference lines on a large surface. These lines can be used to determine if the installation site is square and to create a grid of layout lines for setting tile.
TRIM PIECES: Units of various shapes consisting of items such as bases, caps, corners, moldings and angles necessary to achieve installations of the desired sanitary and architectural design.
TROWEL: A notched trowel is used to apply/spread a pre-determined amount of tile adhesive. Notched trowels are available with various sized and shaped notches to accommodate the needs of many tile installation applications.
TUMBLED TILE: A finish achieved by placing stone tiles in a tumbling machine, sometimes with the addition of acids, to soften the edges and give the surface a worn look.
UNDERLAYMENT: An application of a relatively thin layer of mortar primarily used to level out-of-plane surfaces such as concrete slabs. Cement Backer Boards (CBUs) are also referred to as underlayment.
UNGLAZED TILE: A hard, dense tile of uniform composition, without glazing.
UNMODIFIED THINSET: Contains no additives. You can include your own additives to create modified thinset. See also THINSET and MODIFIED THINSET.
UNMODIFIED TILE MORTAR: A mixture of Portland cement with sand and additives imparting water retentivity, which is used as a bond coat for setting tile. Normally, when this mortar is used, neither the tile nor the walls have to be soaked during installation. See also DRY-SET MORTAR.
UNSANDED GROUT: Portland cement based or epoxy based grout without sand as an ingredient. Typically used in joints that are smaller than 1/8″.
URETHANE: An elastomeric polymer with excellent chemical and water resistance. Single component (moisture cure) and 2-part (chemical cure) systems are available. Both types may be applies in a fluid state and cure (polymerize) after installation. Typical tile industry applications include sealants, caulks, waterproofing membranes and high performance flexible adhesives.
V-CAP TRIM: V-shaped trim tile used on the front edge of a countertop. The tile’s top surface is gently curved upward at the front edge to prevent water from running onto the floor.
VAPOR BARRIER: Waterproof membrane placed under concrete floor slabs.
VERTICAL BROKEN JOINT: Style of laying tile with each vertical row of tile offset for one-half its length.
VITRIFICATION: The condition resulting when kiln temperatures are sufficient to fuse grains and close pores of a clay product.
VITREOUS TILE: Tile that has a water absorption rate of more than 0.5%, but not more than 3%.
WALL TILE: Glazed tile with a body suitable for interior use. Not expected to withstand excessive impact or be subject to freezing/thawing conditions. It is not appropriate for use on a floor.
WARPAGE: Dimensional defect of a tile’s surface flatness. A condition where one corner of a tile is not in the same plane as the other three. Tolerances are given in ISO 13006 Normative annex.
WATERPROOFING MEMBRANE: A covering applied to a substrate before tiling to protect the substrate and framing from damage by water. May be applied below mortar beds or directly beneath this-set tiles.
WEEPHOLE: Opening at the base of a shower drain to collect moisture collected above membrane and dispense it into drain.
WET AREAS: Tile surfaces that are either soaked, saturated or subjected to moisture or liquids (usually water) such as gang showers, tub enclosures, showers, laundries, saunas, steam rooms, swimming pools and exterior areas.
WOOD FLOAT: Sometimes used in place of the flat trowel for floating mortar. It is good for smoothing small irregularities on the mortar bed, working the surface of the mortar before troweling on the pure coat, or compacting floor and deck mortar.