Solid Wood vs Engineered Flooring

The question of solid wood versus engineered wood comes up in almost every UK renovation that involves timber flooring. The honest answer is that for most residential projects in 2026, especially those with underfloor heating or any degree of humidity variation, engineered wood is the better technical choice. Solid wood still has a place, but it demands the right conditions.

Solid wood flooring typically costs £55–£120/m² fully fitted. Engineered wood costs £40–£90/m². The price gap is smaller than many people expect; the performance gap is larger.¹

What the Products Actually Are

Solid wood is milled from a single piece of timber from top to bottom, typically 18–22 mm thick. Every millimetre is real wood, although only the wood above the tongue can ever be sanded away. It can be sanded down and refinished many times over its life.²

Engineered wood has a real hardwood top layer, generally 2.5–6 mm thick, bonded to a cross-layer core that is usually plywood or softwood.³ The top surface is indistinguishable from solid wood in look and touch; the multi-layer core is what provides dimensional stability.

The Core Issue: Moisture Movement

Timber is hygroscopic, it absorbs and releases moisture with changes in relative humidity. In UK homes, indoor relative humidity usually sits between about 35% and 65%, lower in winter when central heating dries the air and higher in summer.⁴ This causes wood to expand and contract across its grain.

A solid board moves as one piece of timber, so wider boards move more, and across a whole room the movement adds up. Solid floors therefore need a perimeter expansion gap, usually hidden under the skirting boards, or they can buckle when the boards take up moisture. Even a well-laid solid floor may show small gaps between boards in the winter heating season.⁴

Engineered wood’s cross-layer core restrains this movement, which is what makes engineered boards much more stable than solid ones.³

Head-to-Head Comparison

Underfloor Heating: A Clear Winner

Solid wood and underfloor heating are a difficult combination. The heating season dries the boards, so they shrink and open wider gaps than normal, and repeated cycles can cause cupping or splitting.⁵ Makers disagree on whether to allow it at all. Woodpecker says its solid wood flooring is not suitable for underfloor heating.² Junckers, by contrast, approves its solid hardwood floors over UFH provided the surface of the boards stays at or below 27°C.⁵

Engineered wood, glued directly to the heated subfloor with a flexible adhesive, handles UFH well, and underfloor heating suppliers generally recommend it over solid wood.⁶ Its cross-layer core tolerates the heating cycles far better. Whichever you choose, check the maker’s maximum floor surface temperature, which is typically 27°C.⁷ A thin board glued down without extra underlay lets the heat through best.

If you have or plan to install UFH, choose engineered wood.

Sanding and Longevity

This is where solid wood wins. Only the wood above the tongue can be sanded away, not the full thickness of the board, but on a typical solid board that is still more than most engineered boards carry, so a solid floor can be brought back to near-new several times over its life.

With engineered boards the wear layer sets the limit. Woodpecker, for example, advises sanding no more than once per millimetre of wear layer, so its 4 mm wear layer allows about three re-sands with the last millimetre left for wear.⁸ A thin 2–3 mm layer allows one or two, and very thin veneers are best not sanded at all.

If you are laying flooring in a historic property, period renovation, or a room that will see heavy foot traffic for decades without replacement, solid wood’s long sanding life is a genuine advantage.

Installation: Practicalities

Solid wood is normally glued to the subfloor or secret-nailed over a timber subfloor, and most makers say it should not be floated.² A few systems are the exception: Junckers lays its solid hardwood boards as a floating floor on a clip system.⁴ Fixing the boards down limits where solid wood can be used (not over flexible timber subfloors that bounce or squeak) and makes installation slower and more disruptive.

Engineered wood can float on underlay, be glued down, or be secret-nailed, giving much greater flexibility.³ A floating install is reversible and faster; glue-down is permanent but performs better underfoot and over UFH.

Both need a flat, dry subfloor, to the flatness tolerance in the maker’s fitting instructions. Acclimatisation advice varies by maker. Woodpecker asks for its engineered boards to settle in the room for at least two days before fitting.³ Junckers says its solid boards should be laid immediately after delivery, once the building is at its normal humidity.⁴

Cost in Practice

For a 30 m² living room:

The saving from engineered is real but not dramatic at mid-range quality. Where the gap widens is at the premium end: very wide, character-grade solid oak in exotic cuts can cost £70–£100/m² supply-only, versus similar-looking engineered at £40–£65/m².

Which Should You Choose?

Choose solid wood if:

• You have a timber subfloor with no underfloor heating
• You want maximum sanding and refinishing longevity (heirloom-quality floors)
• You are renovating a period property where authentic materials matter
• Room humidity will be well-controlled (good extract ventilation, consistent heating)

Choose engineered wood if:

• You have or plan underfloor heating
• The subfloor is concrete
• You want wide boards
• Humidity in the room may vary (kitchen, basement, room with poor ventilation)
• You want an easier, potentially reversible installation

For the majority of UK renovation projects, modern homes, kitchen extensions, open-plan spaces with UFH, flats, engineered wood is the more sensible choice. Solid wood is not obsolete, but it works best in the specific conditions it was designed for.