Flooring Glossary

Every term here is defined in plain English. Where a definition rests on a standard or on legislation, the source is linked so you can check it yourself.

Wood

Brushed

A surface treatment that opens the soft grain with a wire brush so the texture of the timber is felt as well as seen.

Engineered wood flooring

A board with a real wood wear layer bonded to a cross-bonded plywood or HDF base, so the finished board moves far less with humidity than a solid board of the same thickness. BS EN 13489:2023 - Wood-flooring and parquet. Multi-layer parquet elements

Grading

A description of how much knot, sapwood and colour variation a batch contains. It is an appearance classification, not a quality or strength classification.

Janka hardness

A measure of how much force embeds a steel ball halfway into a timber sample. It ranks species against each other and says nothing about the finish, which is what usually fails first.

Lacquered finish

A film finish on the surface of the board. It resists spills well and cannot be spot-repaired — damage means sanding the area back.

Lamella

Another word for the wear layer of an engineered board.

Moisture content

The weight of water in a piece of timber as a percentage of its dry weight. Wood swells and shrinks as it changes.

Oiled finish

A penetrating finish that sits in the timber rather than on it. It can be spot-repaired without redoing the whole floor and needs periodic reapplication.

Sanding and refinishing

Removing the top fraction of a millimetre of a wood floor with an abrasive machine and applying a new finish. FAQ about flooring - Kährs

Smoked oak

Oak darkened right through by reaction with ammonia rather than by a surface stain, so a scratch does not show a pale line.

Solid wood flooring

A board milled from a single piece of timber through its full thickness. BS EN 13226:2009 - Wood flooring. Solid parquet elements with grooves and/or tongues

Wear layer

The layer of real wood above the tongue on an engineered board. It is what can be sanded, so it decides how many times the floor can be refinished. FAQ about flooring - Kährs

Laminate

AC rating

The abrasion class of a laminate floor under EN 13329. It is the single number that separates a floor that survives a hallway from one that does not. Environmental Product Declaration - Direct Pressure Laminate Floor Covering (DPL Floor Covering), owner of the declaration: European Producers of Laminate Flooring e.V. (EPLF), decl. no. EPD-EPL-20210138-CBE1-EN

HDF core

A dense fibreboard panel used as the structural core of laminate and some engineered boards. It swells irreversibly if water sits on a joint.

Laminate flooring

A photographic decor layer over an HDF core, sealed under a transparent wear layer of resin. There is no wood at the surface. BS EN 13329:2016+A2:2021 | 31 Oct 2021 | BSI Knowledge

LVT, SPC and vinyl

EN 16511

The European standard for modular multilayer floor coverings with a mechanical lock — the family that rigid-core vinyl belongs to. BS EN 16511:2023 - Modular mechanical locked floor coverings (MMF). Specification, requirements and test method for multilayer modular panels for floating installation

LVT

A vinyl floor covering supplied in planks or tiles, with a printed decor under a clear wear layer. ISO 10582:2017 - Resilient floor coverings - Heterogeneous poly(vinyl chloride) floor covering - Specifications

SPC

A rigid-core vinyl floor whose core is a mineral-filled polymer, stiff enough to bridge small irregularities in the subfloor that a flexible vinyl would telegraph. Multilayer Modular Flooring in focus - MMFA (Multilayer Modular Flooring Association)

Water resistance

The distinction that matters is between a covering whose material does not absorb water and an installation that keeps water out. A waterproof plank over an open joint still lets water reach the subfloor.

Wear layer thickness

The thickness of the clear layer above the decor on a vinyl floor. It is the number that predicts service life; the overall board thickness does not, and neither does the use class — the class describes intensity of use, not millimetres. ISO 10582:2017 - Resilient floor coverings - Heterogeneous poly(vinyl chloride) floor covering - Specifications (ISO catalogue page, abstract)

WPC

A rigid-core vinyl with a foamed rather than mineral-filled core: warmer and softer underfoot than SPC, less dimensionally stable in heat.

Patterns and formats

Bevel

A chamfer along the edge of a board that makes each plank read as a separate piece and hides small differences in height between neighbours.

Chevron

Blocks cut at an angle at both ends so they meet point to point, producing a continuous unbroken V.

Herringbone

Rectangular blocks laid at a right angle to each other so the ends of one row meet the sides of the next, producing a staggered zigzag.

Plank width

The face width of a board. Wider boards show more of the grain and fewer joints, and move more across their width for the same change in humidity.

Versailles panel

A square framed panel with a woven or diagonal infill, laid as a unit rather than board by board.

Subfloor and screed

Box hygrometer test

A sealed hood taped to the slab until the air under it reaches equilibrium with the base, then read. Digital Hygrometer - Technical Data Sheet, F. Ball and Co. Ltd

Damp-proof membrane

A barrier between the ground and the floor build-up. On a ground floor its presence and condition decide what may be laid. Approved Document C - Site preparation and resistance to contaminants and moisture, 2013 edition (HM Government)

Screed

A layer laid over the structural floor to give a flat surface at the right level, and to bury underfloor heating pipes where there are any. Data Sheet No. 18 Introduction - screed materials to EN 13813 (Tarmac)

Screed drying

The wait between laying a screed and covering it. Screed reaches walk-on strength long before it is dry enough to cover. Drying of Screeds - Ronacrete

Self-levelling compound

A pourable compound that finds its own level and corrects a subfloor that is out of tolerance.

Subfloor

Whatever the new floor is laid on: a concrete slab, a screed, a timber deck or an existing covering. CFA Guide to Contract Flooring - Contract Flooring Association

Subfloor moisture

The residual moisture in a concrete or screed base, measured as the relative humidity in air trapped against it. Laying over a wet base is the most expensive avoidable mistake in flooring. F. Ball and Co. Ltd - Digital Hygrometer, Technical Data Sheet

Surface regularity

How flat the subfloor is, measured as the largest gap under a two-metre straightedge. It is a tolerance, and floor coverings each have one. Surface regularity - straightedge method | The Concrete Society

Suspended timber floor

A ground floor of boards on joists over a ventilated void, rather than on a slab. Common in British housing built before roughly 1930.

Underfloor ventilation

The airflow through the void beneath a suspended timber floor. Blocking it creates a damp problem that the new floor gets blamed for.

Installation

Acclimatisation

Leaving the boards in the room where they will be laid, at the temperature and humidity they will live in, before fitting. CFA Guide to Contract Flooring - Contract Flooring Association

Expansion gap

The space left between a floating floor and every fixed object around it, so the floor can grow and shrink without lifting. EPLF Technical Bulletin — Installation of Laminate Floor Coverings (06/2022), 6.4 Edge gaps

Floating installation

The floor is not fixed to the base. The boards lock to each other and the whole surface moves as one. EPLF Technical Bulletin – Installation of Laminate Floor Coverings (English edition 06/2022), European Producers of Laminate Flooring

Flooring adhesive

The bonding system for a glue-down floor. Which one is right depends on the covering, the base and the residual moisture.

Glue-down installation

The covering is bonded to the base across its whole area. It cannot move independently, so the base has to be right. EPLF Technical Bulletin – Installation of Laminate Floor Coverings (English edition 06/2022), European Producers of Laminate Flooring

Room conditions

The temperature and relative humidity of the room before, during and after fitting. A floor laid into unheated damp air behaves differently once the heating is on. Prior to installation — MMFA (Multilayer Modular Flooring Association)

Secret nailing

Fixing solid boards through the tongue into joists or a batten, so no fixing is visible on the surface.

Underlay

The layer between a floating floor and the base. It levels out minor irregularity, adds impact sound reduction, and often carries the moisture barrier. Underlays — MMFA (Multilayer Modular Flooring Association)

Underfloor heating

Floor surface temperature

The temperature limit at the top of the floor covering over a heating system. It is a limit on the floor, not on the water in the pipes. Uponor underfloor heating/cooling — Planning information (Technical Information TI-1186660)

Heating commissioning

Running a new underfloor heating system through a full heating and cooling cycle before the covering goes down, so the screed does its moving first. CFA Guidance Document — Beyond Installation: Guidance on Underfloor Heating (Contract Flooring Association)

Thermal resistance

How much the floor build-up resists the passage of heat. Over underfloor heating there is a ceiling on it, and underlay plus covering together have to stay below it. Uponor underfloor heating/cooling — Planning information (Technical Information TI-1186660)

Tog

A unit used for underlay in the UK. It converts directly to thermal resistance, which is the number underfloor heating cares about. CFA Guidance Document — Beyond Installation: Guidance on Underfloor Heating (Contract Flooring Association)

Underfloor heating

A heating system in the floor build-up. It changes the specification of the covering above it, not just the comfort of the room. BS EN 1264 — Water based surface embedded heating and cooling systems (BSI series landing page)

Sound

Approved Document E

The part of the English building regulations that sets sound insulation requirements between dwellings. It applies to the separating floor, which in a flat is your floor and your neighbour's ceiling. The Building Regulations 2010, Schedule 1, Part E - Resistance to the passage of sound (legislation.gov.uk)

Impact sound

The noise a footstep makes in the room below, as opposed to the noise it makes in the room you are standing in. Approved Document E - Resistance to the passage of sound, 2003 edition incorporating 2004, 2010, 2013 and 2015 amendments (Table 0.1a)

Impact sound improvement

How much a covering or underlay reduces impact sound compared with the bare structural floor, expressed in decibels. ISO 717-2:2020 - Acoustics - Rating of sound insulation in buildings and of building elements - Part 2: Impact sound insulation (ISO catalogue)

Pre-completion testing

Testing the finished separating floors of a building against the required values before it is signed off. Approved Document E - Resistance to the passage of sound (2003 edition incorporating 2004, 2010, 2013 and 2015 amendments), paragraphs 1.2 and 0.2

Porcelain and outdoor

Outdoor porcelain paving

Porcelain in a thicker format intended for terraces and paths, laid on a bedding system rather than an adhesive bed.

Porcelain tile

A dense fired ceramic with very low water absorption, which is what lets the same body be used outdoors in a British winter.

Slip resistance

How much grip a surface offers, measured with a pendulum. It is a property of the surface in the state it will be used in — wet, if it will be wet. HSE - Assessing the slip resistance of flooring (GEIS2)

Measuring and ordering

Ordering by square metre

Flooring is priced per square metre but sold by the pack, so the number that leaves the warehouse is always rounded up to a whole pack.

Waste allowance

The percentage added to the measured area to cover offcuts, damage and pattern matching. There is no standard for it — the figure is trade practice.

Classification

Use class

A two-digit classification of how hard a floor covering is expected to be used: the first digit is the setting, the second the intensity. How to use the Floor Covering Standard Symbols (FCSS) — EUFCA, symbols per EN 15398

Care

Cleaning and care

How a floor is cleaned decides much of how long it lasts. Standing water is the common denominator behind most avoidable failures. Basic cleaning — MMFA (Multilayer Modular Flooring Association)

Standards, marking and consumer law

Consumer Rights Act 2015

The Act that sets what a consumer may expect of goods sold to them, and what happens when goods fall short. Consumer Rights Act 2015, section 9 (Goods to be of satisfactory quality), subsection (3)

Declaration of Performance

The manufacturer's declared performance for a construction product against a harmonised standard. It is the document behind the marking, and it is the thing to ask for. Regulation (EU) No 305/2011 (assimilated), Article 4 - Declaration of performance

EN 14041

The harmonised standard under which resilient, textile and laminate floor coverings declare their essential characteristics. SLAETTEN laminate flooring — Declaration of Performance, IKEA of Sweden

Formaldehyde class

A classification of formaldehyde release from wood-based panels. OSB with Emission Class E1 - What Does This Mean? — SWISS KRONO

FSC and PEFC

Chain-of-custody schemes that trace certified material through the supply chain. Forest Stewardship Council — What do the FSC labels mean? (chain of custody certification)

Guarantee and warranty

A manufacturer's promise, which sits on top of the consumer's statutory rights and cannot replace them. Consumer Rights Act 2015, section 30: Goods under guarantee — legislation.gov.uk

Made-to-order exception

The exception to the right to cancel for goods made to the consumer's specification or clearly personalised. The Consumer Contracts (Information, Cancellation and Additional Charges) Regulations 2013, regulation 28 (Limits of application: circumstances excluding cancellation), paragraph (1)(b)

Price display

How a price must be presented to a consumer, including charges that are unavoidable. Digital Markets, Competition and Consumers Act 2024, section 230 (Omission of material information from invitation to purchase), subsection (4)

Reaction to fire

The classification of how a floor covering behaves in a fire. The 'fl' in the class marks it as a floor classification rather than a wall or ceiling one. Commission Delegated Regulation (EU) 2016/364 on the classification of the reaction to fire performance of construction products, Annex (as retained in UK law)

Review claims

What a trader may and may not say about customer reviews, and who enforces it. Digital Markets, Competition and Consumers Act 2024, Schedule 20: Commercial practices which are in all circumstances considered unfair

Right to cancel

The right to cancel a contract made at a distance within a fixed period, subject to exceptions. The Consumer Contracts (Information, Cancellation and Additional Charges) Regulations 2013, regulation 30 (Normal cancellation period), paragraph (3)

Short-term right to reject

The consumer's right to reject faulty goods within a fixed period of taking ownership. Consumer Rights Act 2015, section 22 (Time limit for short-term right to reject), subsection (3)

Timber due diligence

The obligation on whoever first places timber on the market to exercise due diligence about its legality. Regulation (EU) No 995/2010 (assimilated), Article 4 - Obligations of operators

UKCA and CE marking

The marking that accompanies a declaration of performance for a construction product placed on the market in Great Britain. Regulation (EU) No 305/2011 (assimilated), Article 4 - Declaration of performance

Common questions

Every term here appears again on the local pages, where the same specifications are set against the housing stock of a particular place. Browse by town and region.