What it is called, by market
One concept, four markets. Where a name means something else locally, the card says so rather than leaving you to find out on site.
United Kingdom
Close, not identicalchipboard
also particle board, flooring grade, P5, moisture-resistant chipboard
Graded P1 to P7 under BS EN 312. Domestic flooring is normally P5, which is moisture-resistant and tongue-and-grooved; the grade is what matters and the word does not carry it.
Australia
Close, not identicalparticleboard
also chipboard, structural flooring, yellow tongue
Yellow tongue names the flooring grade by the colour of its tongue — a genuinely useful convention, since it identifies the grade at a glance on site in a way a British board does not.
United Statesyours
Same word, different thingparticleboard
also chipboard, PB, underlayment
Mostly a furniture and shelving material. American subfloors are overwhelmingly OSB or plywood, so a specification calling for particleboard underfoot reads as an error rather than a grade choice.
Canada
Same word, different thingparticleboard
also chipboard, MDF core, underlayment
As the United States, with OSB the default sheathing and subfloor material.
The governing standard, by market
United Kingdom
BS EN 312 / BS EN 13986
Particleboard grades P1 to P7 and their requirements, and wood-based panels for use in construction.
United States
ANSI A208.1 / APA rated sheathing
Particleboard grades for industrial and furniture use, and the panel ratings that govern structural sheathing instead.
Calculators for this
Each works in either measurement system, and the terminology on the page follows whichever market you have selected.
Frequently asked questions
- Is all chipboard the same thing in different thicknesses?
- No, and it is the assumption behind most chipboard failures. The European grading runs from P1, a general-purpose board for dry interior use, up through P5, which is load-bearing and moisture-resistant, to P7 for heavy-duty humid conditions. They look similar on a stack and behave nothing alike: ordinary board exposed to water swells irreversibly, loses its strength, and does not recover when it dries — the particles have been pushed apart and the resin bond is gone. P5 flooring board is made with a different resin system and is dimensionally far more stable when wet, which is why it survives a building being closed in and why a bathroom floor in the wrong grade fails around the WC and the bath within a few years. The grade is printed on the board; it is worth reading.
- Why does a chipboard floor squeak and dip at the joints when plywood does not?
- Because of how the panel carries load at its edge and what holds the edge down. Chipboard flooring is tongue-and-grooved so that adjacent boards support each other along their long edges, and that joint depends on being glued: the specification is to glue the tongue, not merely to push it home. Left unglued, the edge relies on the tongue alone, and the repeated flexing of two boards moving independently wears the joint, dips under foot and squeaks. The second factor is the fixing — chipboard's screw-holding is weaker than plywood's, so a screw that is overdriven strips its own hole and the board lifts back onto it. The practical consequences are that chipboard flooring is a glued-and-screwed installation rather than a nailed one, and that a squeaky chipboard floor is rarely fixed by adding screws in the same places.
- Chipboard, MDF or OSB — what actually decides?
- Particle size and where the strength comes from, which sends each to a different job. CHIPBOARD is pressed from relatively large flakes and chips, giving reasonable stiffness across a panel and mediocre edges. MDF is milled to fibres and pressed to a uniform density, so it has no grain and a machinable edge — which is why it takes a moulded profile and a painted finish and why it is the joinery and moulding material. OSB is made from long strands laid in oriented layers, so it behaves far more like a structural panel and is what carries load in a North American wall or roof. Asking chipboard to do OSB's job underfoot in a wet area, or MDF's job on a moulded edge, is the usual way each of them disappoints.