The tiling glossary.

Also called: 2 cm porcelain slab, Outdoor porcelain slab

An outdoor porcelain slab about 20 mm thick, far stronger under load than a standard tile. Depending on the manufacturer’s instructions, it is laid on pedestals over a waterproofing layer, on a gravel bed or bonded to a concrete slab, and when laid dry it is easy to lift.

In practice: Terrace and outdoor tiling

Also called: Encaustic cement tile, Hydraulic tile

An unfired tile made by pressing a mix of cement, sand and pigments, with a coloured decorative layer a few millimetres thick on the surface. Porous and sensitive to stains and acids, it needs a protective treatment before grouting, a suitable adhesive and cleaning with pH-neutral products.

In practice: Floor and wall tiling

Also called: Glazed wall tile, Faience

A glazed ceramic tile with a porous body, lighter and easier to cut than porcelain. Its high water absorption, often above 10%, limits it to indoor walls: bathrooms, kitchens, splashbacks. It is not designed to take foot traffic on a floor.

In practice: Wall tiles and splashbacks

Also called: Engineered parquet, Engineered hardwood

Parquet made of several layers: a hardwood wear layer bonded to a backing of plywood, softwood or fibreboard. More stable than solid wood, it can be floated, glued or sometimes nailed, and generally suits underfloor heating better. The thickness of the wear layer limits how often it can be sanded.

In practice: Parquet flooring

Also called: Frost-proof tile

A tile that withstands freeze-thaw cycles without cracking or flaking, thanks to very low water absorption. The property is stated on the manufacturer’s technical data sheet. It is essential for terraces, balconies and outdoor steps exposed to frost, where porcelain is the usual choice.

In practice: Terrace and outdoor tiling

Also called: Through-body porcelain

Porcelain tile whose colour and composition are the same through its whole thickness, generally with no glaze on the surface. A chip or a worn patch shows far less, which makes it a reliable choice for hallways, shops and other high-traffic areas.

In practice: Floor and wall tiling

An igneous rock made mainly of quartz, feldspar and mica, very hard and of low porosity. Resistant to abrasion and less sensitive to acids than marble, it suits busy floors, steps and outdoor areas, especially in a flamed or bush-hammered finish that is rougher and less slippery.

In practice: Marble and natural stone

A metamorphic rock formed when limestone recrystallises, prized for its veining and its ability to take a high polish. Like any calcareous stone, it is etched by acids (vinegar, lemon, limescale removers) and scratches more easily than porcelain, so it needs an impregnating sealer and pH-neutral cleaning.

In practice: Marble and natural stone

Also called: Mosaic tiles, Mosaic sheets

A covering made of small tiles a few centimetres across, in glass, ceramic, porcelain or stone, usually mounted on a mesh backing so they can be laid in sheets. It follows the multi-directional falls of a shower floor and suits niches and curved surfaces.

In practice: Walk-in shower

Any stone quarried and then cut into tiles or slabs: marble, travertine, limestone, granite or slate. Each stone has its own porosity, hardness and sensitivity to staining, which guide the choice of room, adhesive, finish and protective treatment.

In practice: Marble and natural stone

Also called: Porcelain stoneware

A ceramic tile made from clays and feldspars, pressed and fired at a very high temperature, with water absorption of no more than 0.5%. Dense and resistant to wear, stains and, in most cases, frost, it suits floors and walls, indoors and out. It comes glazed or unglazed.

In practice: Floor and wall tiling

Also called: Rectified-edge tile

A tile whose edges are ground after firing to give very consistent dimensions and sharp, square edges. This precision allows narrow joints and a more continuous look, provided the substrate is very flat. A joint is still always required, at least as wide as the minimum set by the manufacturer and the laying rules.

In practice: Large-format tiles

Also called: Solid hardwood flooring

Parquet whose boards are each cut from a single piece of wood through their full thickness, so it can be sanded and refinished several times. More sensitive to changes in humidity than engineered boards, it is nailed or glued down, and only suits underfloor heating under certain conditions.

In practice: Parquet flooring

A clay tile fired at a lower temperature than porcelain, usually unglazed, porous and in warm shades from red to ochre. Traditional French tomettes, often hexagonal, and handmade tiles belong to this family. It needs a protective treatment, and its frost resistance must be checked before any outdoor use.

In practice: Floor and wall tiling

A limestone formed by deposits from springs rich in calcium carbonate, recognisable by its natural cavities. It is sold filled, with the holes closed, or unfilled for a rawer look, in honed, polished, brushed or tumbled finishes. Like marble, it is sensitive to acids and is cleaned with neutral products.

In practice: Marble and natural stone

Also called: Zellij

A small glazed terracotta tile, handmade in the Moroccan tradition. Its irregular edges, uneven surface and shade variations give a lively wall with shifting reflections. It is mostly laid on walls with tight joints, and industrial zellige-effect tiles reproduce its look.

In practice: Wall tiles and splashbacks

Also called: Double spreading

The technique of spreading adhesive on the substrate with a notched trowel and also coating the back of the tile with a thin layer. This gives full contact with no voids under the tile. The laying rules require it in particular above a certain tile size and outdoors.

In practice: Large-format tiles

Also called: Cementitious grout, Tile grout

A cement-based grout mixed with water, worked into the joints with a rubber float and then cleaned off with a sponge. Classed CG1 or CG2 under EN 13888, it comes in many colours. Easy to apply, it remains slightly porous and can stain more readily than epoxy grout.

In practice: Floor and wall tiling

Also called: Epoxy resin grout

A two-part grout made of epoxy resin and hardener, classed RG under EN 13888. Non-porous, it stands up very well to water, stains and household cleaners, which makes it a good choice for showers, splashbacks and worktops. It sets quickly and must be cleaned off carefully during application.

In practice: Walk-in shower

Also called: Silicone joint, Sealant joint

A joint made with an elastic sealant, silicone or polymer, at changes of plane (internal corners, floor-to-wall junctions) and around a bath, shower tray or worktop, where cement grout would crack. In wet rooms a sanitary sealant with a fungicide is used, and it is renewed when it deteriorates.

In practice: Bathroom tiling

Also called: Floating floor

A way of laying parquet in which the boards are joined to each other, by click joints or by gluing the tongues and grooves, without being fixed to the substrate. The floor rests on an underlay, with a vapour barrier over mineral substrates and an expansion gap around the edges. It is covered by NF DTU 51.11.

In practice: Parquet flooring

Also called: Penetrating sealer, Stone sealer

A liquid treatment applied to a porous material (natural stone, terracotta, cement tiles) that soaks into its pores to make it water and oil repellent without forming a surface film. It limits staining while keeping the natural look of the material, and is renewed depending on the product and wear.

In practice: Marble and natural stone

Also called: Setting out, Tile layout

A setting-out plan, drawn up before work starts, that fixes the direction of the tiles, the pattern, the starting point, the joint width and where the cuts fall. It balances the cuts, avoids thin strips at the edges and lines the joints up with doors, walls or a shower drain.

In practice: Floor and wall tiling

Also called: Channel drain, Linear drain

A long, narrow drain with a stainless steel grate or a tileable insert, set along a wall or across the shower. It only needs a fall in one direction, which allows large tiles to be laid with few cuts. Its trap must stay accessible for cleaning.

In practice: Walk-in shower

Also called: Tile lippage, Uneven tile edges

A difference in height between the edges of two adjacent tiles. Visible in low-angle light and sometimes felt underfoot, it is kept down by a flat substrate, back-buttering, a levelling system and a reduced offset for long tiles. The laying rules set tolerances that must be met.

In practice: Large-format tiles

Also called: Thick-bed laying, Sand and cement bed

A traditional method in which tiles are set on a thick bed of fresh sand and cement mortar, which takes up large differences in level. Covered by NF DTU 52.1 for floors, it remains common for natural stone, terracotta, outdoor paths and steps. It needs a longer drying time.

In practice: Terrace and outdoor tiling

Also called: Field joint, Expansion joint

A joint cut through the tiles and their adhesive to divide a large area into bays, so it can absorb expansion and shrinkage. Filled with a flexible sealant or fitted with a profile, it is positioned according to the area, the exposure or the presence of underfloor heating. The building’s structural expansion joints must always be carried through the tiling.

In practice: Floor and wall tiling

Also called: Raised outdoor floor, Adjustable pedestals

Dry laying of outdoor slabs, often 20 mm porcelain, on height-adjustable pedestals placed on a waterproofing layer or a slab. The finished surface is level even when the substrate slopes, water drains away underneath and each slab can be lifted to reach the drains.

In practice: Terrace and outdoor tiling

Also called: Perimeter gap

A gap left between the tiling and walls, columns, thresholds or pipes, so the covering can move without being restrained. Hidden by the skirting or filled with a flexible sealant, it stops a floor from lifting or cracking. For parquet, the same gap is called the expansion gap.

In practice: Floor and wall tiling

Also called: Skirting board, Baseboard

A strip fitted along the bottom of the walls, in tile, wood or MDF, that protects the wall from knocks and mopping and hides the perimeter joint. A tiled skirting is often cut from the floor tiles, bonded and lined up with their joints. With parquet, it is fixed to the wall, never to the floor.

In practice: Floor and wall tiling

Also called: Step nosing

The front edge of a step, where the tread meets the riser, which takes the most impact and wear. It is finished with a special bullnose tile, an anti-slip metal profile or a stone piece. Outdoors, it must remain slip-resistant and clearly visible.

In practice: Terrace and outdoor tiling

Also called: Honing, Marble restoration

Machine grinding with progressively finer diamond abrasives that flattens a marble or stone floor and then brings back its shine. After laying, honing removes lippage and polishing gives the chosen finish. It is also used to restore dull or scratched marble.

In practice: Marble and natural stone

Also called: Door sill, Threshold strip

A transition piece set in a doorway, in stone, tile or a metal profile, that deals with the change in height and floor covering between two rooms. At an outside door, the threshold slopes slightly outwards to shed rainwater.

In practice: Marble and natural stone

Also called: Cementitious adhesive, Thinset

A cement-based tile adhesive supplied as a powder and mixed with water, spread in a thin layer with a notched trowel to bond the tiles. The right one depends on the substrate, the tile size, the room and its use, and is identified by its class (C1, C2, S1, S2). It differs from ready-mixed paste and resin adhesives.

In practice: Floor and wall tiling

Also called: Edge trim, Finishing profile

An aluminium, stainless steel, brass or PVC strip set under the edge of the tiles to protect and finish exposed edges: external corners, splashback edges, steps and transitions between two floor coverings. It avoids raw edges and chipping. For a more discreet corner, the tiles can also be mitre-cut.

In practice: Wall tiles and splashbacks

Also called: ATec, CSTB technical approval

An opinion issued by an expert committee run by the CSTB on the fitness for use of a product or system not covered by a DTU, such as under-tile waterproofing, an uncoupling membrane or a flowing screed. It sets the installation conditions, which matter for durability and insurance. For CE-marked products it is called a Document Technique d’Application.

In practice: Walk-in shower

Also called: DIN 51097

A rating of a floor’s slip resistance for bare feet, based on an inclined ramp test defined by the German standard DIN 51097. Class A is the least demanding and class C the most slip-resistant. For a shower floor, class B or C is generally sought.

In practice: Walk-in shower

Also called: P3 levelling compound

A classification of floor levelling compounds by their resistance to indentation and traffic, rated P2, P3 or P4 (P4S for the most demanding uses). It is read against the P index of the room’s UPEC rating: a P3 compound suits a room rated P3, for example. The manufacturer’s data sheet also gives the permitted thicknesses.

In practice: Screed and levelling

Also called: DTU 26.2

The French unified technical document for screeds and slabs made with hydraulic binders, such as traditional sand and cement screed. It covers bonded, unbonded and floating screeds: thicknesses, mixes, joints, protection and drying. Most flowing screeds are covered by an Avis Technique instead.

In practice: Screed and levelling

Also called: DTU 51.1

The French unified technical document for nailed parquet, fixed to battens or to a timber subfloor. It sets the moisture content of the wood, how the battens are spaced and fixed, how the substrate is prepared and the expansion gap around the edges. It is the traditional method for solid parquet.

In practice: Parquet flooring

Also called: DTU 51.11

The French unified technical document for the floating installation of parquet and engineered floorings with a wood surface. It deals with the underlay, the vapour barrier on mineral substrates, expansion gaps, thresholds and areas that need splitting up. Laminate floors, which have no wood surface, fall outside its scope.

In practice: Parquet flooring

Also called: DTU 51.2

The French unified technical document for parquet fully glued to a screed, a slab or a panel. It sets the flatness and moisture requirements for the substrate, the choice and spread rate of adhesive, and the expansion gaps. Gluing gives a stable floor that sounds less hollow than a floating one.

In practice: Parquet flooring

Also called: DTU 52.1

The French unified technical document for mortar-bed floor coverings, meaning floors set on a bed of fresh mortar. It specifies the substrates, the mortar mix and thickness, any separating layer and the joints, for ceramic tiles and natural stone alike, indoors and outdoors.

In practice: Marble and natural stone

Also called: DTU 52.2

The French unified technical document (DTU), published as an NF standard, that sets the rules for bonding ceramic tiles and natural stone on floors and walls, indoors and outdoors: accepted substrates, preparation, adhesive choice, joints and tolerances. Products outside its scope follow an Avis Technique or the manufacturer’s instructions.

In practice: Floor and wall tiling

Also called: R rating, DIN 51130

A rating of a floor’s slip resistance for people wearing shoes, based on an inclined ramp test defined by the German standard DIN 51130. It runs from R9, the least slip-resistant, to R13, the most. Outdoors and on floors that are often wet, R11 or higher is generally the target.

In practice: Terrace and outdoor tiling

Also called: Decennial insurance, Ten-year guarantee

The builder’s liability under the French Civil Code (articles 1792 onwards) that covers, for ten years after handover, damage that undermines the soundness of the work or makes it unfit for its purpose. The tradesperson must be insured for it, and you can ask for the insurance certificate before signing the quote.

In practice: Floor and wall tiling

Also called: EN 12004, C2 S1 adhesive

Codes from the EN 12004 standard that describe a tile adhesive: C for cementitious, 1 for normal or 2 for improved, plus F (fast setting), T (reduced slip on walls), E (extended open time) and S1 or S2 for a deformable or highly deformable adhesive. A C2 S1 adhesive is common for large formats and outdoors.

In practice: Large-format tiles

Also called: UPEC classification

A classification set by the CSTB (the French building research centre) that rates a floor covering’s resistance to wear (U), indentation (P), water (E) and chemicals (C), each letter followed by an index. Rooms are classified the same way: the covering chosen should match or exceed the room on every index.

In practice: Floor and wall tiling

Also called: EB+ privatif, Wall moisture exposure classes

A CSTB classification of rooms according to how much water their walls are exposed to: EA, EB, EB+ privatif (private use), EB+ collectif (shared use) and EC, from driest to wettest. The walls of a shower in a home are generally EB+ privatif. The class sets which substrates are accepted and whether under-tile waterproofing (SPEC) is needed.

In practice: Bathroom tiling