AC4 or AC5: what the wear class is actually telling you
The number on the pack is an abrasion test, not a durability rating. Here is what it predicts, what it does not, and where the money is better spent.
Every laminate pack carries an AC number, and almost every specification argument about laminate is really an argument about that number. It is worth knowing what it measures, because it measures one thing quite narrowly.
What the test does
AC ratings come from EN 13329. A rotating abrasive wheel runs on the decor surface until the pattern wears through at a defined point. More revolutions, higher class. That is the whole test. AC3, AC4, AC5 and AC6 are steps on a single abrasion scale.
So the wear class tells you how long the printed decor survives grit being ground into it. It says nothing about impact, nothing about how the joint behaves when a radiator leaks, and nothing about whether the board will cup in a room that hits 30 °C behind a south-facing window.
Where each class belongs
- AC3 — bedrooms and low-traffic residential only. We do not stock it; the saving against AC4 is not worth the callback.
- AC4 / class 32 — the general residential and light-commercial floor. Hallways, kitchens, rental turnover. Most of what leaves this warehouse.
- AC5 / class 32–33 — heavier residential and real commercial traffic. Offices, small retail, student housing.
- AC6 / class 33 — shops, showrooms, reception floors. The heaviest class made in laminate.
The interesting case is that AC5 is not automatically the safer buy. Swiss Krono's Kronostep K638 is AC5 at 7 mm and about 25 PLN net per square metre; Egger's PRO Large Aqua+ is AC4 at 8 mm and about 61. The Egger is more than twice the price and a lower wear class. It is also the one we would put in a kitchen.
Why, if the class is lower
Because the failure mode in a kitchen is not abrasion. It is water reaching the core through the joint, the HDF swelling, and the joint edges lifting into a ridge you can feel through a sock. Wear class does not model that at all.
Aqua+ cores are treated so that swelling under the same soak test is a fraction of standard HDF, and the joint geometry is cut to hold a surface spill for a day. That is a different property, tested differently, and it is the one that decides whether the floor survives a dishwasher.
What to specify on, instead of AC alone
- Thickness and core density. A 12 mm board on a slightly uneven screed is forgiving; a 7 mm board telegraphs everything underneath it.
- Joint system. 5G and Megaloc close tighter and survive more lifts than a simple angle-angle click.
- Water behaviour, if the room has plumbing in it. Ask for the swell figure, not the marketing name.
- Bevel. Four-sided bevels hide a 1 mm level change between planks; square edges do not.
- Impact sound, if there is a flat below. An integrated pad or a separate underlay is what the neighbour actually experiences.
Spend on the class where the floor will genuinely be ground down — a shop entrance, a corridor in student housing. Everywhere else, spend on the core and the joint and take AC4.
