Laminate flooring thickness

Laminate flooring thickness chart

Laminate is sold in millimeters even in the US. The figure is the plank alone: a pad attached to the back adds another 1 to 2 mm that is not counted in the name.

In fractions: 6 mm is about ¼ in, 8 mm about 5/16 in, 10 mm about ⅜ in and 12 mm just under ½ in.

Is 6mm laminate flooring any good?

Over a flat concrete slab, in a bedroom or a rental, yes — 6 mm laminate of a decent AC class wears as well as a thicker plank of the same class. Its weaknesses are the hollow sound and a subfloor that is anything less than flat: the thin core flexes into dips and the joints work loose. Over a wood subfloor, or anywhere you will hear the floor from below, go to 8 mm or more.

Is there 20 mm laminate?

Not as laminate. The thickest planks stop at about 12 to 14 mm; a figure near 20 mm is usually the plank plus its pad and underlayment, or an engineered wood floor, which has a real wood top layer and is a different product.

Is thicker laminate flooring better?

Better in three ways, and no better in the one people assume.

• It sounds less hollow. A floating floor drums under heels; more fiberboard core means more mass and less drum. This is most of what you are paying for in 12 mm.
• It bridges small dips. A stiffer plank spans a low spot in the subfloor instead of flexing into it, which is what breaks click joints over time. It does not replace leveling — it buys a little tolerance.
• It locks more firmly. A deeper edge has a deeper tongue and groove, which holds a little better on a less-than-perfect subfloor. Peaking and gapping, though, come from a missing expansion gap or from moisture — no thickness prevents them.
• It does not wear longer. The surface that takes the traffic is a thin layer of aluminum oxide over the photo print, and it is the same on a 7 mm plank as on a 12 mm one of the same grade. That is what the AC rating measures.

AC rating: the number that decides wear

AC classes come from the European standard EN 13329, which grinds, stains, burns and drops weights on the surface; the standard runs from AC1 to AC6, and the descriptions below are the uses retailers attach to each class. Read it alongside thickness, not instead of it: two planks of the same thickness can be two classes apart.

There is no "AC4 wear layer thickness" to look up: the class is set by how many turns of an abrasive wheel the surface survives, not by a wear layer measured in mils — that figure belongs to vinyl plank. So the order of decisions is: AC3 or AC4 first, then the thickness the room's subfloor and noise call for. An AC4 8 mm floor will outlast an AC2 12 mm one.

Underlayment thickness for laminate

Laminate wants a thin, firm underlayment, and thicker is not better here. A soft pad lets the planks rock at the joints with every step, and the click locks wear loose. Most laminate makers specify foam of about 2 to 3 mm, and many installation guides exclude joint damage over anything spongier from the warranty. Never lay laminate over carpet pad.

Most makers do not allow a second foam layer under a plank that already has a pad attached: the extra give works the click joints loose, and many installation guides exclude it from the warranty. A few allow their own thin underlayment under their own planks — the box says which.

Is thick underlay better for laminate?

No. Thick underlay is right under carpet and wrong under laminate, where 3 mm is about the limit. The carpet pad thickness and density guide covers the other case, and the underlay calculator counts the rolls for either.

Finished floor height, doors and transitions

The floor you lay is the plank plus the underlayment, and that is the height the doors have to clear and the transition strips have to meet.

A door needs trimming if the new floor takes up more than the gap under it; a 12 mm plank on 3 mm foam is 15 mm, just under ⅝ in. Leave a ¼ in expansion gap at every wall and doorframe — ⅜ in on runs longer than about 40 ft, or a transition break if your product's guide sets a maximum run — and cover it with baseboard or shoe molding.

Before any of this, the subfloor has to be flat: most makers ask for 3/16 in over 10 ft, about 5 mm over 3 m. A thicker plank does not get you out of that. High spots are ground down and dips deeper than that are filled with a leveler — self-leveling concrete thickness covers how thin and how thick it can go.

The laminate flooring calculator counts the boxes, the underlayment rolls and the transition strips for your rooms.

Trim to finish the edges is sized in baseboard and crown molding sizes.

Figures: thickness and underlayment ranges as sold by US retailers; AC classes from EN 13329. Flatness and underlayment limits vary by maker and are set in each product's installation guide, which is what the warranty is judged against.