Choosing a floor: engineered oak, solid wood, vinyl and what survives underfloor heating

The floor is the biggest single surface in an apartment, the one thing every other material has to sit against, and the decision most people make last and fastest. It is also the one that is hardest to reverse. Choosing it well is mostly a matter of matching the construction of the board to the conditions of the building, and in Luxembourg that increasingly means underfloor heating, concrete slabs and apartments where the neighbour below can hear everything.

The four realistic options

Solid wood

One piece of timber through its full thickness, usually 15 to 22 millimetres. It can be sanded and refinished many times, it ages beautifully and it is the only floor that genuinely improves over thirty years.

The catch is movement. Solid wood expands and contracts with humidity, which makes it the worst choice over underfloor heating and a demanding one in an apartment with dry winter air. It is also the most expensive to buy and install.

Engineered wood

A real wood wear layer, typically 2.5 to 6 millimetres, bonded to a plywood or HDF core. The cross-laminated core is dimensionally stable, which is the entire point.

For a Luxembourg apartment, engineered oak is the default answer and it is not close. It looks identical to solid, it tolerates underfloor heating, it can be sanded once or twice if the wear layer is 3 millimetres or more, and it can be glued down for acoustic performance. The only decision that matters is wear layer thickness: below 2.5 millimetres you own a laminate with a wood veneer.

Laminate

A photographic print under a melamine wear layer on a fibreboard core. Modern laminate is far better than its reputation, cheap, extremely scratch-resistant and available in convincing patterns.

It cannot be repaired or refinished, it sounds hollow underfoot unless carefully underlaid, and it is unforgiving about standing water. It is a sensible choice for a rental with high turnover and a poor choice for a home you intend to keep.

Luxury vinyl and rigid core

A printed vinyl layer over a rigid or flexible core. Fully waterproof, warm underfoot, quiet, thin, and excellent over underfloor heating because it conducts well.

It is the strongest option for kitchens, bathrooms and any apartment where water is a live risk, and the best-quality products are now genuinely convincing. Cheap ones are not, and the difference is visible from across the room.

Underfloor heating changes the answer

A growing share of new apartments in Luxembourg, particularly VEFA schemes at Cloche d'Or, Kirchberg and Belval, are built with underfloor heating running off a heat pump. That system works at a low flow temperature and depends on the floor conducting heat upward efficiently.

• Check the thermal resistance of the whole build-up, board plus underlay. As a working rule the total should stay at or below roughly 0.15 m²K/W. Above that the system fights the floor and your heating bill records the argument.
• Engineered wood and vinyl are compatible. Solid wood generally is not, and thick underlays defeat the system.
• Avoid thick carpet and heavy rugs over the main heat emitters.
• Follow the commissioning procedure. A new screed must be heated up and cooled down on a defined schedule before the floor goes on, and skipping it is the most common cause of gapping.

The acoustic obligation people forget

In an apartment building, impact sound is not only a courtesy issue. Co-ownership rules commonly set a minimum acoustic performance for floor coverings, and replacing carpet with a hard floor without the correct underlay is one of the more frequent sources of dispute between neighbours.

Before you order anything, read the co-ownership regulations and ask the syndic what is required. Then specify an acoustic underlay that meets it, or glue the floor down with an acoustic adhesive, which performs better than a floating floor on foam. The cost difference is small and the alternative is taking the floor up again.

Format, colour and the things that date

• Wide boards read calmer. 180 to 220 millimetres suits most apartment rooms. Narrow strip flooring makes a small room busier.
• Herringbone is beautiful and unforgiving. It needs a level subfloor, more material for waste, and a room large enough to show the pattern. In a 3 by 4 metre room it reads as noise.
• Mid-tone natural oak ages best. Very dark floors show every speck of dust and every scratch. Very white or grey-washed floors are strongly of their moment and will date.
• Matt oil or hardwax finishes can be spot-repaired. High-gloss lacquer cannot, and shows everything.
• Run the boards along the longest wall or toward the main light source. This is a small decision that changes how large a room feels.

Preparing the subfloor, which is where projects fail

More flooring complaints come from what is underneath than from the boards themselves, and the preparation is the part most easily cut from a quotation.

• Levelness. Most manufacturers require the substrate to be flat within roughly 2 to 3 millimetres over 2 metres. A concrete slab in an older Luxembourg building frequently is not, and self-levelling compound is the answer. A floating floor over an uneven base flexes, and the clicks fail.
• Moisture. A new screed holds construction water for weeks. Laying wood over a screed that has not dried produces cupping and gaps that no amount of acclimatisation will reverse. Insist on a moisture reading, not a guess.
• Acclimatisation. Engineered and solid boards need days in the room they will be laid in, in their packaging, before installation. Skipping this is the commonest cause of gapping in the first winter.
• Expansion gaps. Every floating floor needs a perimeter gap, covered by the skirting or a bead. A floor laid tight to the wall will buckle.

Ask any quotation to state the subfloor preparation separately. If it does not appear as a line, it has not been priced, and it will either be skipped or invoiced later as an extra.

Three questions we are asked

What does a decent floor cost?

Prices move, so treat this as structure rather than a quotation. Laminate is the cheapest per square metre, vinyl sits above it, engineered oak substantially above that and solid oak highest. Installation, underlay, skirting and levelling frequently add as much again as the boards. Always price the finished floor, not the material.

Can I lay a new floor in a rented apartment?

Only with the owner's written agreement, and it is rarely worth a tenant's money. If the existing floor is tired, a large flat-weave rug transforms a room for a fraction of the cost and leaves with you.

Same floor throughout, or different in each room?

One floor running through the living space, hall and bedrooms makes an apartment feel larger and avoids threshold strips, which are the least attractive detail in any interior. Bathrooms and often kitchens are the sensible exception, where tile or vinyl earns its keep.

Where this fits in a Luxembourg apartment

In the apartments we prepare for sale, replacing a tired floor with mid-tone engineered oak is consistently the single renovation with the clearest effect on both viewing numbers and offers. It is not a cosmetic decision, it is a commercial one.

A useful editorial test for underfloor heating changes the answer is to look at the consequence rather than the headline feature.

One of the easiest mistakes around the four realistic options is judging the visible result while ignoring the process that produces it. For the question raised by “The four realistic options”, the useful detail is not a generic list of advantages. Then ask what happens when one assumption fails.

For the acoustic obligation people forget, note what you can see, what you can measure, what you need to ask and what would be expensive to change. For the question raised by “The four realistic options”, the useful detail is not a generic list of advantages.

A stronger reading of preparing the subfloor, which is where projects fail starts by asking what would change for the resident on an ordinary weekday.