How to use this glossary
This glossary defines the terms flooring businesses, builders, architects and homeowners meet when choosing, specifying and installing timber floorboards and parquet. Terms are listed A–Z. Where a figure or standard is quoted, the source is linked or listed under Sources.
A
Acclimatisation
Letting timber flooring adjust toward the moisture conditions it will live in before installation, usually with the building enclosed and conditions close to normal. See acclimatising oak flooring.
Adhesive (flooring adhesive)
Glue used to bond parquet or boards to a slab or subfloor. Parquet adhesives are usually elastic; some also act as a moisture barrier. The adhesive maker's moisture limits govern use.
AS 2796
The Australian Standard for hardwood flooring, which grades Australian hardwoods into Select, Standard (Medium) Feature and High Feature. It does not grade European oak (ATFA).
AS 3959
The Australian Standard for construction of buildings in bushfire-prone areas. It mainly affects exposed elements such as elevated subfloors and decks, not internal floors over a slab.
AS 4586
The Australian Standard for classifying the slip resistance of new pedestrian surfaces, using the pendulum (P rating) and ramp (R rating) tests.
ATFA
The Australasian Timber Flooring Association, the industry body for timber flooring in Australia, which publishes specifications and consumer information.
B
BAL (Bushfire Attack Level)
A rating of a site's potential exposure to ember attack, radiant heat and flame under AS 3959: BAL-LOW, BAL-12.5, BAL-19, BAL-29, BAL-40 and BAL-FZ. See timber flooring in bushfire areas.
Basketweave
A parquet pattern in which small groups of parallel blocks alternate direction, like woven strands.
Batten
A strip of timber fixed to a slab or frame to support floorboards above it.
Bevel
A small chamfer along the edges of pre-finished boards or blocks that softens the joint line. Site-sanded raw parquet is usually square-edged.
Border
A strip of blocks or boards framing the main field of a parquet floor, often laid parallel to the walls.
BRANZ
Building Research Association of New Zealand, which publishes building guidance, including on timber floors over concrete slabs.
Brushed finish
A surface textured with wire brushes to remove some softer wood and emphasise the grain.
C
Chain of custody (CoC)
Certification that tracks certified timber through each business that owns it, so an FSC or PEFC claim remains valid on the final invoice.
Chevron
A parquet pattern of blocks with angled ends that meet point to point, forming a continuous V or zigzag.
Concrete slab
A concrete floor, either on the ground or suspended. Parquet is commonly glued directly to a flat, dry slab.
Crowning
The opposite of cupping: the centre of a board is higher than its edges, often after a cupped floor is sanded flat and then dries out.
Cupping
Boards whose edges sit higher than their centres, usually caused by more moisture below the board than above.
D
D_fl-s1
A European reaction-to-fire class for floorings under EN 13501-1. "fl" means flooring and "s1" means low smoke. Untreated solid parquet is typically D_fl-s1 (dataholz).
Declaration of Performance (DoP)
A manufacturer's document for a CE-marked construction product, declaring its performance against a harmonised European standard – for wood flooring, EN 14342.
Due diligence
A documented process to gather information, assess and reduce the risk that timber was illegally logged. Required of Australian importers of regulated timber products.
E
EMC (equilibrium moisture content)
The moisture content timber settles at for a given temperature and humidity – about 11% at 25°C and 60% RH, and about 16% at 80% RH (ATFA).
EN 13226
European standard for solid parquet elements with grooves and/or tongues.
EN 14342
European harmonised standard for wood flooring and parquet, covering characteristics such as reaction to fire, formaldehyde and slip, and the basis for CE marking and the DoP.
End-matched
Boards with tongue and groove on their ends as well as their edges.
Engineered flooring
Flooring with a top layer of real timber bonded to a stable base, usually plywood or other timber layers. See solid vs engineered oak.
EUDR
The EU Deforestation Regulation, which applies from 30 December 2026 to operators placing wood products on the EU market or exporting them.
Expansion gap
A gap left at walls and fixed objects so timber can move with humidity, usually hidden by skirting or trims.
F
Feature grade
A grade that allows more natural features such as knots, gum veins or colour variation. In AS 2796, Standard (Medium) Feature and High Feature grades.
Floating floor
A floor not fixed to the subfloor; boards are joined to each other and laid over an underlay.
FSC
Forest Stewardship Council, a voluntary forest certification scheme. See FSC and PEFC certification.
Fumed (smoked) oak
Oak darkened by exposure to ammonia, which reacts with its natural tannins. "Smoked" is also used loosely for dark-stained oak.
G
Glue-down
Installing flooring by bonding it directly to the substrate with adhesive – the usual method for solid parquet on a slab.
Grade
A classification of timber by appearance – how many knots, colour variations and other features are allowed. See oak flooring grades.
Groove
The slot along the edge of a board or block that receives the tongue of the next piece.
H
Hardwax oil
A finish combining natural oils and waxes that penetrates the timber and forms a thin protective surface. Worn areas can often be spot repaired.
Herringbone
A parquet pattern of rectangular blocks laid at 90° so the end of one block meets the side of the next, forming a staggered zigzag.
Hybrid flooring
A rigid-core click flooring (often stone-plastic composite) with a printed decorative layer and a wear layer. Not timber at the surface.
I
Illegal Logging Prohibition Act 2012
Australian law prohibiting the import of illegally logged timber. Reformed by 2024 amendments and the Illegal Logging Prohibition Rules 2024, in force from 3 March 2025 (DAFF).
ISPM 15
The international standard for treating and marking wood packaging such as pallets and crates to prevent the spread of pests.
J
Janka hardness
A measure of timber's resistance to denting: the force (in kN) to press a steel ball halfway into the wood. European oak is about 4.2–6.1 kN; spotted gum about 11 kN (PFC). See the Janka hardness chart.
Joist
A horizontal framing member that supports a suspended timber floor.
K
Kiln-dried
Timber dried in a controlled kiln to a target moisture content before machining.
L
Laminate flooring
Flooring with a fibreboard core, a printed decorative layer and a clear wear layer. Not solid timber.
Levelling compound
A cement-based compound used to flatten a slab before flooring is glued down.
M
Medullary rays
Ribbon-like cells running outward from the centre of the tree. In quarter-sawn oak they show as a distinctive "ray fleck" figure.
Moisture barrier
A membrane, primer or adhesive system that limits moisture moving from a slab into timber flooring.
Moisture content (MC)
The weight of water in timber as a percentage of its oven-dry weight. Install within about ±2% of in-service EMC (WoodSolutions). See moisture content in timber flooring.
MPI
New Zealand's Ministry for Primary Industries, which sets import health standards for wood products.
N
NCC
The National Construction Code, Australia's building code, which sets requirements such as slip resistance for stair treads and fire hazard properties for floor linings.
Nosing
The front edge of a stair tread. Under the NCC, treads or nosing strips need a minimum slip-resistance classification. See slip resistance for timber stairs.
P
P rating
A slip-resistance classification from the wet pendulum test under AS 4586, from P0 (lowest) to P5 (highest).
Parquet / parquetry
Flooring made of small timber blocks laid in a geometric pattern. "Parquetry" is the common Australian term. See parquet patterns.
Pattern parquet
Decorative parquet layouts beyond herringbone and chevron, such as basketweave and panel designs.
PEFC
Programme for the Endorsement of Forest Certification, an umbrella for national forest certification schemes. In Australia, the endorsed scheme is Responsible Wood.
Plain-sawn (flat-sawn)
Timber cut tangentially to the growth rings, giving a cathedral or flame-like grain pattern.
Polyurethane
A film-forming floor coating (water- or solvent-based) that sits on top of the timber, giving a hard-wearing, easy-clean surface.
Pre-finished
Flooring coated in the factory, so it needs no sanding or coating on site.
Prime grade
The cleanest appearance grade of European oak, with even colour and minimal knots and features.
Q
Quarter-sawn
Timber cut roughly at right angles to the growth rings. More dimensionally stable, and in oak it shows the ray fleck figure.
R
Raw (unfinished) flooring
Flooring supplied without a factory finish, sanded and coated on site after installation.
Relative humidity (RH)
The amount of moisture in the air compared with the maximum it can hold at that temperature. Drives timber's EMC.
Rustic grade
An appearance grade that allows larger knots, more colour variation and other natural features.
S
Sanding
Abrading the floor surface to flatten it and prepare it for coating, or to remove a worn finish.
Sapwood
The paler outer wood of a log. Cleaner appearance grades generally limit it.
Select grade
The AS 2796 grade for Australian hardwood with the fewest natural features.
Skirting
Board fixed along the base of walls, which often covers the expansion gap.
Solid timber flooring
Flooring machined from one piece of timber through its full thickness – for example 18mm solid oak parquet – which can be sanded several times.
Subfloor
The structure the flooring sits on: a concrete slab, plywood, particleboard or joists.
T
T&G (tongue and groove)
A jointing system where a tongue on one edge fits a groove on the next piece, keeping boards aligned and flush.
Tannin
Natural compounds abundant in oak that react with iron, ammonia and some chemicals, causing colour change or dark staining.
Threshold
A trim or transition strip where flooring meets another floor or a doorway.
U
Underfloor heating
Heating installed in or under the floor. With timber, the floor surface is commonly kept to a maximum of about 27°C with a floor sensor (Solid Wood Flooring Co).
Underlay
A layer beneath a floating floor (or some acoustic systems) providing cushioning, sound reduction or moisture protection.
W
Waste allowance
Extra flooring ordered to cover cuts and offcuts – as a rule of thumb about 5–10% for straight boards and 10–15% for herringbone and chevron. See how many boxes of flooring.
Wear layer
On engineered flooring, the top layer of real timber; its thickness limits how many times the floor can be sanded.
Sources
- ATFA / Floor Choices – Hardwood flooring grades: floorchoices.com.au
- ATFA / Floor Choices – Acclimatisation of timber flooring: floorchoices.com.au
- WoodSolutions – Moisture guide: woodsolutions.com.au
- dataholz – Wood flooring and parquet: dataholz.eu
- PFC – Janka rating and floor durability: pfc.com.au
- Flooring Expert – European oak vs Australian hardwood: flooringexpert.com.au
- SlipTest – NCC slip-resistance requirements: sliptest.com.au
- WoodSolutions – Designing in bushfire areas: woodsolutions.com.au
- Department of Agriculture, Fisheries and Forestry – Illegal logging: agriculture.gov.au
- Council of the EU – EUDR revision: consilium.europa.eu
- Solid Wood Flooring Co – Underfloor heating: thesolidwoodflooringcompany.com
Frequently asked questions
What is the difference between parquet and parquetry?
None in practice. Parquet is the international term; parquetry is common in Australia. Both mean timber blocks laid in a geometric pattern.
What does T&G mean on floorboards?
Tongue and groove – a projecting tongue on one edge of a board or block fits into a groove on the next, locking them in line and keeping the surface flush.
What does Prime grade mean for oak?
Prime is the cleanest appearance grade of European oak, with even colour and minimal knots and features. It describes appearance, not strength or sourcing.
What is EMC in timber flooring?
Equilibrium moisture content – the moisture content timber settles at for a given temperature and humidity. Australian interiors typically sit around 8–14% EMC.
What is a wear layer?
On engineered flooring, the top layer of real timber above the base. It limits how many times the floor can be sanded. On solid flooring, the timber above the tongue serves the same purpose.
What is a BAL rating?
BAL (Bushfire Attack Level) rates a site's exposure to bushfire under AS 3959, from BAL-LOW to BAL-FZ. It sets construction requirements for the building.