Squeaky wooden floors: causes and repairs

Øens HåndværkerCentralPublished August 9, 2026 · 11 min. read

A wooden floor creaks because the wood moves with humidity and then either rubs against nails, screws, joists, and neighbouring boards, or becomes strained. The sound is friction or tension, not rot. In the vast majority of homes, creaking is cosmetic, but if it's in the fastening, it won't disappear on its own - nor with just a floor sanding.

• 175 kr/m2Including VAT and a standard finish, from 36 m2
• 24 hoursReply with a fixed price
• Workmanship guaranteeOn all work performed

Why does the floor creak?

The floor creaks because two surfaces work against each other under your weight. The wood absorbs and releases moisture all year round, and when a board has come loose from its nail or joist, it moves a fraction of a millimetre every time you step on it. That movement is heard as a creak.

The Flooring Industry's Floor Facts (DI) describes that a parquet floor is delivered from the factory with an average moisture content of 8%, and that the moisture content in the wood can reach 12-13% in late summer, when the air's relative humidity peaks around 65%. In Floor Facts' own calculation example, the floor is laid in early summer at approx. 40% relative humidity. With an average tangential shrinkage of 0.22% per percentage point of moisture, this means that the floor never stands completely still.

The most common causes of creaking:

• Loose fastening. Nailed boards work their way loose over the years. Screwed floors do so less often. Junckers' installation guide for joist floors states that a creaking subfloor may require re-nailing or re-screwing.
• Joists spaced too far apart, or settled supports. Junckers' design and installation guide for joist floors specifies 600 mm joist spacing in standard spans and 500 mm at joist joints for 22 mm solid wooden flooring. Excessive spacing or a settled support can allow the floor to sag.
• The interlayer is missing or compressed. Junckers' guide prescribes 500 g/m2 floor paper as an interlayer between joist and floor.
• Dry indoor air. As boards shrink, looseness can develop and the tongue-and-groove joints may rub against each other.
• Too small expansion gap. A floor laid too close to a wall, frame, or pipe will push against the structure when it expands.

A calculation example makes the movement concrete. Floor Facts' 2.2 mm per metre per percentage point of moisture means that a 4-metre wide floor surface can move almost 9 mm each time the wood moisture changes by one percentage point. If the floor goes from 8% to 12-13% over the summer, we are talking about 35-44 mm. The number is theoretical free shrinkage, not something you can measure with a tape measure at one end of the living room: the movement distributes itself as small cracks between all the boards and in the expansion joint along the walls. The point is that the movement needs somewhere to go. If it doesn't have space, the boards press against each other, and the floor becomes strained.

What do the different creaking sounds mean?

The sound tells where the problem lies. A short, dry crack in the same spot every time points to a loose board or nail. A soft, sagging sound over a larger area points to the support under the floor. The table below is the diagnosis we use ourselves when assessing a floor before sanding.

When does the floor creak most during the year?

It depends on what triggers the sound, and the two most common causes peak at different times of the year. The Flooring Industry's Floor Facts (DI) points to late summer: "In late summer, the relative humidity in our homes is high, and therefore the moisture content in the wooden floor also increases. The increased humidity means that the floor expands and may become strained, which can result in seasonal creaking sounds when the floor is stepped on." The same source notes that the sounds usually disappear again when the heating season begins and the relative humidity stabilizes.

The other type of creaking goes the opposite way. When the heating season has dried out the indoor air, the boards shrink, cracks open, and a board that has come loose from its nail or joist gets room to move. That sound is friction against the fastening, not tension in the floor surface, and it does not go away on its own when the weather changes.

The season itself is therefore a diagnosis. If the sound comes and goes with the season, it is usually normal movement in the wood. If the creaking remains in the floor all year, or if you can feel the floor giving way underfoot, the cause is fastening or support. If you have underfloor heating under the wooden floor, the seasonal fluctuations typically become more pronounced because the wood is also dried from below.

How do you stop the creaking?

You stop the creaking by first finding the exact point and then working from least to most intrusive effort. A handful of creaky boards are often resolved in an hour. An entire room that sags requires the floor to be partially lifted. The sequence below saves you unnecessary work:

1. Localize the sound. Walk slowly across the floor and mark the points with tape. Get someone else to listen from below if there's a basement or crawl space underneath.
2. Stabilize the indoor climate. If the cracks only appear in winter, a more even humidity level often helps more than any tool.
3. Try the dry home remedy first. Talcum powder or graphite powder brushed into the joint reduces friction between tongue and groove. It works for light creaks but is a dampening, not a repair, and its effect diminishes. Avoid oil and soap in the joints - they penetrate the wood and create dark streaks that only disappear with sanding.
4. Screw the board down. If the creak is over a joist, the board can be pre-drilled and screwed down. The hole is plugged with a wooden plug of the same wood type. This requires you to know exactly where the joist is located and that there are no underfloor heating pipes or electrical wiring in the structure. If in doubt, don't do it.
5. Open the structure for sagging floors. If the support has sunk, no screw from above will help. Here, boards must be lifted, and joists shimmed or supplemented.
6. Combine with surface treatment. If the floor is to be sanded anyway, creak repair, filling of cracks and holes, and plugging are done in the same work process. This way, there is only one dusty process in the home.

Does floor sanding remove creaking?

No. Floor sanding removes wear layers, scratches, dark stains, and old treatments, but it does not change how the boards are fastened or supported. Creaking is movement in the structure, and movement cannot be sanded away. Therefore, we always repair creaks before the machine touches the floor.

The order matters in terms of cost. Screws, plugs, and leveling create holes and minor damage to the surface, and these must be sanded and treated afterward to disappear. If you fix the creaking after a freshly lacquered sanding, you effectively pay for the surface twice. If you need to assess how much the floor needs, the guide on the difference between light sanding, sanding, and planing provides a quick overview, and when a wooden floor is ready for sanding reviews the visible signs.

A floor cannot be sanded indefinitely. Solid wooden floors typically tolerate 4 to 6 full sandings over their lifetime; engineered flooring allows fewer, depending on the wear-layer thickness. See our guide to how many times a wooden floor can be sanded reviews how to assess the wear layer yourself.

What does it cost to get the floor fixed?

Standard floor sanding with a standard finish costs 175 kr per m2 including VAT from 36 m2. Squeak repairs are separate: securing a few accessible boards is a different job from lifting a floor to investigate its structure. We assess the likely cause and agree the repair scope and price before starting.

• 65 m2 pine floor, standard sanding and a standard finish: an illustrative 11.375 kr including VAT, before any separately agreed repairs.
• 45 m2 parquet floor, standard sanding and a standard finish: an illustrative 7.875 kr including VAT. A light surface refresh is quoted separately.
• 80 sq m plank floor: approx. 14,000 DKK.

The lifespan of the surface is worth considering at the same time: a lacquered floor typically lasts about 10 years before needing to be sanded again, while an oiled floor requires re-treatment approximately every 1-2 years and can be spot-repaired along the way. If you are unsure about the choice, the guide on what floor sanding costs per sq m reviews the price drivers line by line. The service itself can be found under floor sanding and surface treatment.

Do floors in apartments creak differently?

Yes, the cause is different. In apartment buildings, wooden floors rarely rest on a joist layer with air underneath. They are laid as floating floors or on joists on top of a concrete slab, often with a sound-insulating layer in between, and creaking typically occurs in click-joints, due to too small an expansion joint, or where the intermediate layer has been compressed.

Øens HåndværkerCentral is based in Aarhus Ø and works, among other things, in the apartments in Isbjerget, Z-huset, Nicolinehus, Pakhusene and Kanalhusene. Here, there are two practical considerations to keep in mind: the expansion joint along the walls must not be blocked by skirting boards or a new kitchen, and the owner or co-operative association often has rules for floor construction and impact sound, which must be respected when interfering with the construction. The guide on floor sanding in apartments covers access conditions, dust, and consideration for neighbours.

When should you call a professional?

Call a professional when the floor visibly sags underfoot, when creaking has occurred after water damage, or when the sound is present all year round regardless of the weather. These are signs that support or moisture is the cause, and it cannot be solved from above with screws and talcum powder.

Also be aware of the working environment if you start working yourself. The Danish Working Environment Authority considers work with wood dust from hardwoods, and other wood dust in high concentrations over prolonged periods, to be carcinogenic, and the limit value for inhalable wood dust is 1 mg/m3 measured as an average over an 8-hour workday. Dust must be removed as far as possible by extraction at the source, and this also applies to a rented sanding machine in your own living room. Professional equipment sands with point extraction so that dust does not end up in the home. If you want to keep the freshly sanded result looking nice afterward, it starts with the correct daily washing of the wooden floor.

We reply within 24 hours, confirm a fixed quotation before starting and provide a workmanship guarantee on the work. Write or call 20 98 88 11 for a fixed price for your floor.

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Øens HåndværkerCentral

We sand and surface-treat floors, stairs, balconies, wooden terraces, and worktops - based in Aarhus Ø and taking on projects nationwide. You get a fixed price before work begins and a workmanship guarantee on the completed work.

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