Engineered Wood Flooring Thickness Guide: How to Choose

Thickness is one of the first decisions you will make when choosing an engineered wood floor and it is also one of the most misunderstood. A thicker board is not automatically a better board and the number that matters most for how long your floor lasts is not the overall thickness at all. This guide explains the two measurements that actually count, walks through every common thickness from 10mm to 20mm and helps you match the right board to the right room.

At Grosvenor Flooring in Altrincham we supply engineered wood flooring in the full range of thicknesses across South Manchester and Cheshire and this is the same advice we give customers in the Wood Room every week. Get thickness right and you get a floor that suits your subfloor, your doors and the way each room is used.

Key takeaways

Two measurements matter: the overall board thickness and the wear layer, which is the real hardwood on top. The wear layer is the one that decides how long the floor lasts.
Overall thickness is mostly about feel, stability and build height. Most UK engineered boards run from 10mm to 20mm.
The wear layer sets how many times a floor can be sanded and refinished. A 2mm layer refinishes once or not at all, while a 4mm to 6mm layer can be renewed several times over decades.
Thinner boards suit height-restricted rooms and underfloor heating. Thicker boards feel more solid and last longer through refinishing.
For most homes a 14mm or 15mm board with a 3mm to 4mm wear layer is the sweet spot. Busy hallways and kitchens benefit from a thicker wear layer.

The Two Measurements That Matter

Every engineered board has two thickness figures and confusing them is the most common mistake buyers make. The first is the overall thickness, the full depth of the board from the wear surface down to the bottom of the core. The second is the wear layer, the slice of genuine hardwood bonded to the top. You can have two boards of identical overall thickness with completely different wear layers and it is the wear layer that determines the real quality and lifespan of the floor.

The reason is simple. Only the hardwood wear layer can be sanded and refinished. The plywood or timber core beneath it is there for stability and height, not for the surface. So when you compare boards, look past the headline thickness and ask what the wear layer is. A 15mm board with a 4mm wear layer is a better long-term floor than an 18mm board with a 2mm wear layer, even though the second sounds thicker.

Overall Thickness Explained

Overall thickness affects three things: how substantial the floor feels underfoot, how much it can absorb minor subfloor imperfections and how much height it adds to the room. Most UK engineered wood sits between 10mm and 20mm. Thinner boards are easier to fit where height is tight, such as against existing floors or under doors and they transfer heat more readily over underfloor heating. Thicker boards feel closer to solid wood and give a little more acoustic warmth, but they raise the floor level more and cost more to produce.

Overall thickness also influences how the board is fitted. Thinner boards are often glued down, while thicker boards can be floated over an underlay or fixed down depending on the subfloor. Our complete installation guide covers the fitting methods in full.

Wear Layer Explained

The wear layer is the part of the floor you actually live on and it is what lets an engineered floor be renewed rather than replaced. UK wear layers typically run from 2mm to 6mm. A thin 2mm wear layer can usually be sanded once, or in some cases not at all, so the floor lasts as long as its surface finish holds up. A 3mm to 4mm wear layer can be sanded a couple of times and a premium 5mm to 6mm wear layer can be refinished several times, which comfortably takes a floor across the life of most homes.

As a rough guide, a floor is sanded roughly every five to ten years if it needs it at all, so a thicker wear layer translates directly into decades of extra service. If long life and the ability to refresh the floor matter to you, spend your budget on the wear layer rather than the overall thickness. Our engineered wood care guide explains how to protect the wear layer you have so it lasts as long as possible.

Engineered Wood Thickness Compared

Overall thickness	Typical wear layer	Refinishing	Best for
10mm	2mm to 3mm	Once, or none	Height-restricted rooms, underfloor heating, matching existing floors
11mm to 13mm	2.5mm to 3mm	Once or twice	Bedrooms and lower-traffic rooms, tighter build heights
14mm	3mm to 4mm	Two to three times	Most rooms, living and dining rooms, general use
15mm	4mm	Two to three times	All-round choice, good balance of feel and value
18mm to 20mm	5mm to 6mm	Several times	Hallways, kitchens, busy homes, near-solid feel

Figures are typical rather than absolute. Always check the wear layer quoted for the specific board, because it varies between ranges.

Thickness by Thickness

9mm and 10mm Engineered Wood

The thinnest boards we stock are the practical answer where height is the constraint. A 9mm or 10mm board is ideal when you are matching the level of an existing floor, working under doors that cannot be trimmed or fitting over underfloor heating where a low profile helps heat through. The wear layer is thinner, so refinishing is limited, but for many rooms a well-finished thin board gives years of good service.

11mm to 13mm Engineered Wood

The 11mm to 13mm range is a useful middle ground for bedrooms and lower-traffic rooms where you want a little more substance than a 10mm board without raising the floor too far. Wear layers here are typically around 3mm, giving you a refinish or two down the line.

14mm and 15mm Engineered Wood

This is the range most people should be looking at. A 14mm or 15mm board pairs a substantial, solid-feeling floor with a 3mm to 4mm wear layer that can be refinished a couple of times and it sits comfortably within the range that works well over underfloor heating. For living rooms, dining rooms, bedrooms and general use across a home it is the sweet spot of feel, longevity and value.

18mm and 20mm Engineered Wood

The thickest boards give the closest experience to solid wood with the most substantial feel underfoot and a bit more acoustic warmth. A 20mm board usually carries a 5mm to 6mm wear layer, so it can be sanded several times and will last the life of most homes. These are the boards to choose for the busiest zones, or where you simply want the most solid floor available. The trade-offs are a higher floor level and a higher price.

Thickness and Underfloor Heating

If your room has underfloor heating, thickness takes on a second job: letting heat through efficiently. Wood resists heat, so a thinner board reaches the room faster and lets the system run more economically. Boards in the 10mm to 15mm range sit within the thermal resistance that underfloor heating systems want, while the thickest 18mm and 20mm boards respond more slowly. For the full detail on getting a wood floor right over a heated subfloor, including temperature limits and commissioning, see our dedicated engineered wood and underfloor heating guide and for a wider view our guide to the best flooring for underfloor heating.

Thickness, Fitting and Build Height

Overall thickness has real-world consequences for fitting that are easy to overlook. Every millimetre you add to the floor raises the finished level, which affects how doors open, how thresholds meet other rooms and how skirtings and stairs line up. In a renovation where you are matching into existing floors, a thinner board is often the pragmatic choice even if a thicker one would feel nicer, simply because it fits the space you have. In a new build or a full refit, where levels can be set from scratch, you have a free hand to choose thickness on feel and longevity alone.

It is always worth measuring the gap under your doors and the height of any thresholds before you settle on a thickness and factoring in any underlay. A little planning here avoids the classic problem of a beautiful floor that stops a door from opening.

Which Thickness Should You Choose?

For most homes, a 14mm or 15mm board with a 3mm to 4mm wear layer is the right answer: substantial underfoot, refinishable and suitable for underfloor heating. Choose a thinner 9mm or 10mm board where height is restricted, where you are matching an existing floor or where fast response over underfloor heating matters most. Step up to an 18mm or 20mm board with a 6mm wear layer for the busiest hallways and kitchens, or where you want the most solid, longest-lasting floor and floor height is not a concern. And whatever the overall thickness, let the wear layer be the figure that guides you, because that is what decides how many decades of service you get.

Thickness is only one part of the decision. Species, finish and format all shape the final look and our guides to finishes, parquet patterns, grades and colours and finishes take you through the rest, alongside our overview of the best engineered wood flooring in the UK. If you are still deciding between engineered wood and other floor types, our LVT vs engineered wood and engineered wood vs laminate comparisons are good next reads.

Compare Thicknesses in Person in Altrincham

The easiest way to judge thickness is to handle the boards and stand on them. Our Smart Showroom and Wood Room at 82 Stamford New Road, Altrincham, WA14 1BS is open 24 hours a day, 7 days a week with no appointment needed. Simply request your free door code and visit when it suits you. Inside you can compare our GF Engineered Wood range in plank and herringbone alongside premium brands such as V4, Ted Todd and Woodpecker and feel the difference between thicknesses and wear layers side by side. Whether you are in Altrincham, Hale, Bowdon, Knutsford or anywhere across Cheshire, the showroom is minutes from the M56 and A56.

Frequently asked questions

What is the best thickness for engineered wood flooring?

For most homes a 14mm or 15mm board is the best all-round choice, giving a substantial feel and a 3mm to 4mm wear layer that can be refinished a couple of times. The best thickness for you depends on the room, the subfloor and how much height you can add, but the wear layer matters more than the overall thickness.

Does thicker engineered wood last longer?

Not necessarily. What decides how long a floor lasts is the wear layer, the real hardwood on top, not the overall thickness. A thinner board with a thick wear layer can outlast a thicker board with a thin one, because only the wear layer can be sanded and refinished.

What thickness of engineered wood is best for underfloor heating?

Thinner boards in the 10mm to 15mm range are best for underfloor heating because they let heat through more efficiently. A 14mm or 15mm board is the usual recommendation, balancing fast heat transfer with a substantial feel and a good wear layer. See our underfloor heating guide for the full detail.

How thick should the wear layer be?

For a long-lasting floor, look for a wear layer of 3mm or more. A 2mm layer can usually be sanded once or not at all, while 3mm to 4mm gives a couple of refinishes and 5mm to 6mm can be renewed several times over decades. Busy areas such as hallways and kitchens benefit most from a thicker wear layer.

Is 10mm engineered wood any good?

Yes, in the right place. A 10mm board is ideal where height is restricted, where you are matching an existing floor level or over underfloor heating where a low profile helps. Its thinner wear layer limits refinishing, but for bedrooms and lower-traffic rooms it gives years of good service.

Can all engineered wood thicknesses be sanded?

Only down to the wear layer. Boards with a 3mm to 6mm wear layer can be sanded and refinished, some of them several times. Boards with a very thin 2mm wear layer can usually only be sanded once and some cannot be sanded at all, so they rely on their surface finish for longevity.