At a glance
| Word | What it can mean | Write instead |
|---|---|---|
| Bevel | A very small chamfer, a larger V-groove, or any edge treatment | Edge detail, size and a section drawing |
| Brushed | Timber: wire-brushed grain. Stone: abrasive brushes, rippled face | 'Wire-brushed oak' or 'brushed limestone, sample ref' |
| Hardwood | A broad-leaved tree (botanical), or just a solid timber floor (US trade) | The species, and a hardness test if needed |
| Parquet | A panel (old French sense), or any pattern floor of blocks | 'Panels' or 'loose-lay blocks', with sizes |
| Rift | Timber with rings at about 30 to 60 degrees; used differently in stone | The angle range and the share of each board |
| Plain sawn | Only plain sawn, or any mix of cuts (NWFA/NOFMA) | The cut and the share that must be quartered |
Six words that most often cause trouble. The full A to Z follows.
A board and a stone surface, labelled
A floor is described in words that mean different things to different people, so the first job of a specification is to fix the words. This sheet defines 44 terms for timber and stone floors in plain English, says where each definition comes from, and warns where a word is a trap. The two drawings show a board in section with its parts named, and six stone finishes. The next section shows how the cut of timber and the edge of a board are named.
Where a standard names the terms, it is BS EN 13756 for wood flooring and parquet (BSI lists the 2018 edition as current) and BS EN 12670 for natural stone (BSI lists the 2019 edition as current, and the 2002 edition as withdrawn). We have not read either, so each definition here comes from a document we did read, or says it is trade usage. Check a definition against the standard before you rely on it in a contract.
Cuts and edges
Timber is named by how the log is sawn, and a board by its edges. Both are drawn here in section. The angle of the growth rings to the wide face decides the cut: the Wood Handbook calls 0 to 45 degrees plainsawn and 45 to 90 degrees quartersawn, and the US NWFA/NOFMA standard adds rift at 30 to 60 degrees (rings of that angle the Handbook calls bastard sawn). The trade does not agree where one cut ends and the next begins, so give an angle range or a sample: see timber cuts explained.
Edges have no standard names. A micro-bevel, a bevel and a bombé edge are makers' words for a square, a chamfered and a rounded top edge. Draw the joint in section and say the size.
A to C
Source keys are in square brackets and are explained in the last section. Sheet means another sheet in this library, Trade means trade usage with no standard found.
| Term | What it means | Also called or code | Watch out |
|---|---|---|---|
| Acclimatisation | Leaving flooring in the room, or an equivalent space, until it has reached the moisture content it will have in use. UK guidance gives days (72 hours is common); the US trade body gives no number of days and asks for readings. [DIST; NIG; Sheet: acclimatisation and site conditions] | Also: conditioning (US trade body). | Specify the room conditions and the readings, not a number of days. |
| Antiqued, tumbled (stone) | A stone surface made to look worn, by tumbling, brushing or sanding, so that faces and edges are softened. The name does not say which. BCA lists antique among 'others'. [Sheet: natural stone finishes; BCA] | Also: aged, distressed. | Ask what was done to the stone and approve a sample of the real slab. Tumbled is not among the nine finishes Stone Federation GB lists. |
| Balancing layer (backer) | The bottom layer of an engineered board, opposite the wear layer on top. [Trade] | Also: backing layer. | Ask for the build-up: the thickness and material of each layer are the maker's. |
| Bevel, micro-bevel | A chamfered top edge, cut at an angle so that a small V forms where two boards meet. A micro-bevel is a very small chamfer. A distributor's guideline says that where components have micro-bevelled edges the bevel is to be recreated on any cut edge, such as at a border, with a router and bevel cutter. [DIST; Trade] | Also: V-groove (a larger bevel); square edge means none. | Give the size and draw the joint: 'micro-bevel' has no standard size. |
| Bombé edge | A rounded, domed top edge on a floor board, in place of a straight chamfer. Bombé is French for curved outward. Our Biscuit collection page describes a softly rounded, bombé board. [Trade; Live: /products/flooring/biscuit] | Also: rounded edge. | Give the radius or show the section, and say whether the ends are rounded as well as the long edges. |
| Book-match | Consecutive slices of stone, veneer or timber opened like a book so that the grain or veining mirrors across the join. Four-way and slip matches are variants. [Sheet: stone slab and book-match approval; Trade] | Also: slip match, random match (other layouts). | Approve the slab layout, not a single sample. |
| Border, apron, frame | A band of different pattern or species laid round the field of a floor to frame it and to meet the walls. The US trade body calls the band between border and wall the apron. [Sheet: borders, frames, medallions and inlays; NIG] | Also: frieze (see Frieze). | Draw its width at each wall: it takes up the difference between pattern and room. |
| Brushed | Two meanings. In timber the surface is brushed to wear back the softer wood and leave the harder grain standing; makers list it as a treatment beside oiled, smoked and lacquered. [Live: /products/flooring; Trade] In stone, abrasive brushes wear back the softer minerals, leaving a slightly rippled, low-sheen face; Stone Federation GB lists it among nine finishes. [Sheet: natural stone finishes; SFGB] | Stone: overlaps with leathered. | Say timber or stone, and approve a sample. Makers use brushed and leathered for different textures. |
| Bush-hammered | A coarse, pitted stone surface made by striking with a multi-pointed hammer. BCA lists it among 'others'. [Sheet: natural stone finishes; SFGB; BCA] | Strong grip but hard to keep clean: test a sample. | |
| Click system | An edge profile that locks boards together mechanically. A maker's guide notes that a click board can also be fully bonded. [Trade; MAKER] | Also: locking, glueless. | Ask whether the board is approved for the fixing method and for underfloor heating. |
| Cupping, crowning | Cupping is distortion across a board in which the edges rise above the centre, as when the top face is drier than the underside. The US trade body describes engineered boards dry cupping when humidity stays below the maker's range, and a UK maker says heating a room that has been closed up and damp dries the surface and causes cupping. Crowning is the reverse. [NMAG; MAKER; Sheet: seasonal movement. Crowning: Trade] | Both are moisture problems. See the seasonal movement sheet. |
D to L
| Term | What it means | Also called or code | Watch out |
|---|---|---|---|
| Damp-proof membrane (DPM) | A barrier that stops moisture from the ground or the base reaching the floor. A distributor allows a higher screed humidity (75 % in place of 65 %) where a vapour check or surface damp proof membrane is applied over the subfloor. [DIST; Trade] | Not a damp-proof course. | Say whether it is under the slab, over it or on the surface: they are different things. |
| Engineered wood flooring | A board with a layer of real timber on top, bonded to a core of other layers, built to move less than a single piece of solid timber. It still reacts to low humidity, by dry cupping. [NMAG; Sheet: solid vs engineered. BS EN 13489 covers multi-layer parquet elements; Sheet: wood flooring standards map records the 2023 edition as current] | Not laminate. | Ask for the wear layer thickness: it sets how often the floor can be sanded. |
| Equilibrium moisture content (EMC), moisture content | Moisture content is the mass of water in wood as a percentage of the mass of the oven-dry wood. EMC is the moisture content at which wood is neither gaining nor losing moisture in air of a given humidity and temperature. [WH ch. 4] | Also: MC. | A floor settles towards the EMC of its room: the humidity range sets the swing. |
| Expansion gap | A deliberate space left at the edges of a timber floor, and at fixed obstructions, so that it can swell. Published figures differ: 1.5 mm per metre with a minimum of 10 mm (a UK distributor), at least 12 to 15 mm (a UK maker), ½ in for parquet and ¾ in for solid strip and plank (the US trade body). [DIST; MAKER; NIG] | Also: perimeter gap. | Not a movement joint, which is a break within the floor. The maker states the figure for its floor. |
| Flamed | A rough stone surface made by playing a high-temperature flame over the face so that crystals pop and flake. BCA calls it exfoliated and says it is used outside where slip resistance is a priority. [Sheet: natural stone finishes; SFGB; BCA] | Also: exfoliated. | Sources disagree about which stones suit it. |
| Flat-sawn, plain-sawn | Timber cut tangentially to the growth rings, so the rings meet the wide face at 0 to 45 degrees: cathedral figure and the most movement across the width. [WH ch. 3; Sheet: timber cuts explained] | Also: plainsawn; slash-grained (softwoods). | The US trade standard lets 'plain sawn' flooring contain any mix of plain, rift and quarter sawn. [NN] |
| Floating floor | A floor that is not fixed to the subfloor, only to itself, so it can move as one. [Trade] | In Approved Document E the words mean a floating layer on a resilient layer: see the acoustics sheet. [Sheet: acoustics for wood floors] | |
| Frieze (frise) | A narrow band of boards set round or between panels, or round a pattern. A dealer says 17th century panels were often separated by friezes or shuttle strips; Roubo's chevron floors were laid inside a frieze. [DEAL; MERCH] | Also: navette (strip between panels). | On a drawing say where the band is: in English a frieze is also a wall band. |
| Fully bonded | Fixed over its whole back to the subfloor with adhesive: with a flexible adhesive for design flooring, and with adhesive plus headless pins for parquet strips, in one distributor's guidelines. [DIST] | Needs a flat, dry subfloor: the distributor quotes SR1 and a humidity limit. | |
| Hardwood, softwood | Botanical words. Hardwoods come from broad-leaved (flowering) trees and softwoods from conifers; the words are not a measure of hardness. [WH ch. 3] In US trade usage 'hardwood floor' usually means a solid timber floor. [Trade] | Do not read 'hardwood' as a hardness claim. Ask for a hardness test where it matters. | |
| Herringbone, chevron | Herringbone: square-ended blocks, the end of each meeting the side of the next at 90 degrees. Chevron: angled ends meeting in a V. [Sheet: parquet pattern atlas; herringbone vs chevron] | Chevron: Hungarian point, French herringbone (trade). | Draw the cut angle and say whether a quoted length is the long edge or tip to tip. |
| Honed | A smooth, non-reflective stone surface made with diamond abrasives and not taken to a gloss. BCA calls it more porous than polished. [Sheet: natural stone finishes; BCA; SFGB] | Also: matt (loosely). | Hides etching and fine scratches better than polished. Porosity claims differ: test a sample. |
| Hygrometer test | A test in which a sealed probe measures the relative humidity of a screed or slab, to judge whether a floor can be laid. One distributor says solid subfloors must be checked by hygrometer 'in accordance with British Standards Annex A'; others attribute that annex to BS 8201. [DIST] | Also: RH test. | Limits differ by supplier: ask the maker for its limit and the method. |
| Laitance | A weak, dusty surface skin on a cement or calcium sulphate screed. One distributor asks for subfloors free of laitance and, for anhydrite screed, for the surface to be sanded to remove it and a primer applied. [DIST; Trade] | Not efflorescence. | Say who removes it and who checks that it has gone. |
| Lamella | A word some makers use for the top layer of an engineered board, and others for a strip or slice of timber. [Trade] | Not used consistently: write 'wear layer' and its thickness. | |
| Lamparquet | Thin solid timber strips, narrower and thinner than a plank, for small-scale parquet patterns on a bonded base. BSI lists BS EN 13227:2017 as covering solid lamparquet products and not panels. [Sheet: wood flooring standards map] | Name the pattern, not just the product. | |
| Leathered | A soft, low-sheen stone texture made with diamond brushes that follow the stone's undulations, usually over a honed face. [Sheet: natural stone finishes; SFGB] | Overlaps with brushed. | Hides water spots and fingermarks; texture holds some dirt. |
M to W
| Term | What it means | Also called or code | Watch out |
|---|---|---|---|
| Medullary ray fleck | The shiny flecks on a quarter-sawn oak face, where the cut runs along the rays. The Wood Handbook says quarter-sawn cutting brings out pronounced rays. The NWFA/NOFMA standard treats flecks over 1/16 in (1.59 mm) wide as quarter-sawn character and narrower flecks as rift. [WH ch. 3; NN] | Also: ray fleck. | Say whether fleck is wanted or limited. |
| Navette (shuttle strip) | A narrow strip set between panels in a historic parquet floor; one UK maker shows shuttle connections between its panels. [DEAL; Sheet: parquet panels vs loose-lay] | Also: frieze (loosely). | Draw it if it is wanted: panels with tongue and groove edges do not need one. |
| Panel (parquet), parquet and plancher | A unit of many small pieces assembled in the workshop and laid whole. In the old French sense, as Roubo is quoted, a parquet was the jointed compartment floor and a plancher a floor of boards. [AWAP; Sheet: parquet panels vs loose-lay] | Also: feuille, leaf (historic). | Today 'parquet' is also used for any pattern floor of blocks: say panel or loose-lay. |
| Pendulum test value (PTV) | The result of the pendulum slip test. HSE's table, taken from the UK Slip Resistance Group (2011), calls 0 to 24 high slip potential, 25 to 35 moderate and 36 or more low. BS 7976 was withdrawn in 2022 and replaced by BS EN 16165:2021. [HSE; Sheet: natural stone finishes] | Also: slip resistance value. | Quote the test condition: wet or dry, slider, and the sample. |
| Polished | A gloss, mirror-like stone surface made with diamond abrasives followed by polishing powder. BCA calls polished stone not porous. [Sheet: natural stone finishes; BCA; SFGB] | Shows scratches and etching most; grip can fall when wet. | |
| Quarter-sawn | Timber cut so the growth rings meet the face at 45 to 90 degrees: straight grain, ray fleck in oak and less movement in width. The NWFA/NOFMA standard calls a floor quarter sawn when at least 50 % of each piece has quartered character. [WH ch. 3; NN] | Also: quartered, edge-grained (softwoods). | Ask what share of each board must be quartered. |
| Rift-sawn | Timber with the rings at about 30 to 60 degrees to the face, straight grain and little ray fleck. The NWFA/NOFMA standard asks for at least 75 % of the piece to have rift character. The Wood Handbook has no rift category and calls 30 to 60 degrees bastard sawn. [NN; WH ch. 3] | Also: bastard sawn (WH). | Trade usage: give the angle range or a sample. The word is used differently in stone. |
| Sapwood, heartwood | Sapwood is the band of lighter wood next to the bark; heartwood is the darker wood inside it. [WH ch. 3] | Grades limit sapwood differently: see the wood flooring grades sheet. | |
| Screed | A layer laid over a slab to level it and take the floor finish. One distributor names cement and sand screeds and calcium sulphate (anhydrite) screeds, which need different tests and primers. [DIST; Trade] | Also: anhydrite, liquid screed. | Say which type and who tests it. |
| Secret nailing | Nails driven through the tongue so that no head shows. The US trade body says some 3/4 in parquet can be nailed only where it keeps an exposed tongue to nail into. [NIG ch. 7, ch. 9] | Also: blind nailing. | Not for every board or pattern: ask the maker. |
| Slab (stone) | A large flat piece of stone, bigger and thicker than a tile. BS EN 12058 covers slabs for floors and stairs and BS EN 12057 modular tiles. [Sheet: natural stone flooring specification] | Approve the slab, not a tile cut from another. | |
| SR1 | A flatness tolerance for a subfloor, quoted by one distributor as a maximum 3 mm gap under a 2 m straight edge at any point. [DIST] | Which part of BS 8204 defines SR1 is not agreed between sources: confirm before quoting a standard. | |
| Tongue and groove | A joint in which a projecting tongue on one board fits a groove in the next, locking the edges and keeping the surface level. The NWFA/NOFMA standard sets a tolerance on the fit between tongue and groove. [NIG; NN] | Also: T&G. | Both boards need the same profile; a border may need a false tongue. |
| Versailles, Chantilly, Arenberg | Three named panel patterns. One reference dictionary defines Versailles as a border with compartments positioned diagonally to it, Chantilly as a border with compartments at right angles to it and Arenberg as a border with different geometric figures. [VD; Sheet: parquet panels vs loose-lay] | Sources describe Chantilly differently: ask for the maker's panel drawing. | |
| Wear layer | The visible top layer of real timber on an engineered board. Its thickness limits how many times the floor can be sanded; the US trade body does not recommend sanding below 3/32 in (2.38 mm). [NMAG; Sheet: solid vs engineered] | Also: top layer (lamella, loosely). | Quote it in millimetres. |
| Wood moisture equivalent (WME) | A moisture-meter reading on a timber subfloor, calibrated to timber; one distributor asks for a timber subfloor under 14 % WME. [DIST] | A meter reading, not a laboratory moisture content. |
UK and US words, and writing terms into a specification
The words that cross the Atlantic do not always mean the same. Hardwood is botanical in the Wood Handbook and loose in the US trade. Subfloor and radiant heat are US words that UK guidance writes as subfloor or base and underfloor heating. Plainsawn and plain sawn are the same cut, which UK sources also call flat sawn. The US trade body measures in inches, converted here to millimetres at 25.4 mm to the inch.
A term in a specification is only as good as the sample behind it. For any word in the table that describes how a surface looks (honed, brushed, leathered, antiqued, bombé) the sample decides, not the dictionary. See sample hierarchy and approval and stone sample, slab and book-match approval.
The sources behind the keys
Several definitions come from suppliers and trade bodies, not from a standard. The keys in square brackets point to this table.
| Key | Source read | Date |
|---|---|---|
| WH | US Forest Products Laboratory, Wood Handbook (FPL-GTR-282), chapters 3, 4 and 13 | 2021 |
| NN | NWFA/NOFMA International Standards for Unfinished Solid Wood Flooring | April 2018 |
| NIG | NWFA Installation Guidelines, chapters 7 and 9 | revised 02.2016 |
| NMAG | NWFA Hardwood Floors magazine, 'Tis the Season | updated 6 Mar 2026 |
| DIST, MAKER | A UK distributor's installation guidelines; a UK maker's long and wide plank guide | Jan 2024; June 2023 |
| SFGB | Stone Federation Great Britain, Natural stone in your home (list of nine finishes, no definitions) | undated |
| BCA | Singapore Building and Construction Authority, Natural Stone Finishes, section 2.1.3 | 10 Apr 2018 |
| HSE | HSE, Assessing the slip resistance of flooring, as used on our finishes sheet | web page updated 5 Jun 2023 |
| AWAP, DEAL, VD, MERCH | A Walloon heritage agency sheet, a dealer's article, an online illustrated dictionary and a merchant's history, as on our panels sheet | 2020 to 2026 |
| Sheet | Another sheet in this library, which lists its own sources | 5 to 6 Nov 2026 |
| Trade, Live | Trade usage with no standard found; one of our own live pages |
Specification wording
Paste into your schedule or specification and replace anything in [square brackets] with your own figures. Wording is a starting point: your specification governs.
Board cut and edges
Boards [engineered oak, [4] mm wear layer] cut [quarter sawn: growth rings at 45 to 90 degrees to the face on not less than [ ] % of each board, ray fleck [wanted / limited]]. Edges [micro-bevel of [ ] mm on all four edges / square edge / bombé edge of [ ] mm radius on the long edges], tongue and groove on all four edges, as section drawing [ref] and approved sample [ref].
Stone finish
Stone [name, quarry reference] with a [honed] finish on all exposed faces and visible edges, to match approved sample [ref] cut from the production slab. Finish name is to be read as the sample, not as a general description. Slip: pendulum test value [36] or more on a wet sample (BS EN 16165), test report before fabrication.
Terms
Where a term in this specification is not defined by [BS EN 13756 / BS EN 12670 / the workshop's drawing], it has the meaning shown on the approved sample and the layout drawing [ref]. The workshop is to query any term it reads differently before production.
Terms used on this page
- Medullary ray fleck
- The shiny flecks on a quarter-sawn oak face where the cut runs along the rays. The NWFA/NOFMA standard counts flecks over 1.59 mm wide as quarter-sawn character.
- Sapwood, heartwood
- Sapwood is the band of lighter wood next to the bark; heartwood is the darker wood inside it. Floor grades limit sapwood differently.
Standards and sources
- BS EN 13756:2018 (wood flooring and parquet, terminology): BSI: Current, published 28 February 2019. Not read.
- BS EN 12670:2019 (natural stone, terminology): BSI: Current, published 30 June 2019; the 2002 edition is withdrawn. Not read.
- BS 8201:2011: BSI: Current (31 October 2011). Not read.
- Wood Handbook (2021); NWFA/NOFMA standard (2018); BCA Natural Stone Finishes (2018): read. The keys are on the web page.
Questions we are asked
What is a bombé edge on a floor board?
A rounded, domed top edge in place of a straight chamfer. Bombé is French for curved outward. It is a maker's term with no standard size, so give the radius or show the section on the drawing.
What is the difference between a bevel and a micro-bevel?
Both are chamfered top edges. A micro-bevel is a very small one and a bevel a larger V. Neither has a standard size, so state the size. A distributor's guideline says a micro-bevel must be recreated on any cut edge, such as a border.
What is rift-sawn timber?
Timber cut so that the growth rings meet the face at about 30 to 60 degrees, giving straight grain and little ray fleck. The US NWFA/NOFMA standard asks for at least 75 % of a piece to have that character. The Wood Handbook has no rift category and calls 30 to 60 degrees bastard sawn, so give the angle range or a sample.
What is laitance?
A weak, dusty skin on the surface of a cement or calcium sulphate screed. One distributor asks for subfloors free of it and, for anhydrite screed, for the surface to be sanded and primed before adhesive is applied.
What is the difference between honed, polished and leathered stone?
Polished is a gloss, mirror-like surface; honed is smooth and non-reflective, made with diamond abrasives and not taken to a gloss; leathered is a soft, low-sheen texture made with diamond brushes. Names vary between workshops, so approve a sample of the real slab.
Is hardwood flooring harder than other flooring?
Not necessarily. Hardwood is a botanical word for timber from broad-leaved trees. In US trade usage 'hardwood floor' usually just means solid timber. If hardness matters, ask for a hardness test.
What does SR1 mean?
Installers quote SR1 as a subfloor flatness tolerance of no more than 3 mm under a 2 m straight edge. Sources do not agree which part of BS 8204 defines it, so confirm before quoting a standard.
Download the factsheet
A two-page A4 PDF with the six trouble words, the labelled board and stone finishes, the 17 most useful definitions and specification wording, to keep with your project file.