Sanding solid wood floors and floorboards
A solid plank floor is one of the most durable options you can have in your home, and therefore, sanding a plank floor is an investment that pays off for decades. While a thin engineered wood floor can only withstand one or two sandings, a solid wood floor with wide planks can be sanded repeatedly, often through several generations. This is the core reason why sanding a solid wood floor makes so much sense: you restore a completely new look without tearing anything up. In this guide, we'll look at how many times you can sand a plank floor, the difference between pine, oak, and hardwood, handling gaps and cracks between wide planks, and choosing a finish. If you want a price immediately, you can read about what floor sanding costs or go directly to our page on floor sanding.
Sanding a plank floor: why solid wood is the most durable type of flooring
A solid plank is one piece of wood, typically 20 to 30 mm thick, but only the usable wood above the tongue-and-groove joint is available for sanding. Engineered flooring has a thinner real-wood wear layer, often 3 to 4 mm, over a supporting core. Measure the remaining layer before deciding how much can safely be removed.
Well-maintained solid wooden floors can last 50, 80 or more than 100 years where enough usable wood remains for renovation. Wide planks also have fewer joints per square metre than smaller parquet blocks, giving the floor a calmer visual pattern.
How many times can you sand a plank floor?
The short answer: many more times than most people think. Each sanding removes only a fraction of a millimetre of wood. A thorough sanding of a wood floor down to bare wood typically removes 0.5 to 1 mm, while a light sanding that just refreshes the surface before a new finish removes almost nothing.
A solid plank floor has a wear layer of 6 mm or more above the tongue and groove, so the floor can withstand numerous full sandings and even more light ones. Here's a realistic estimate:
| Floor type | Wear layer above groove | Number of full sandings (approx.) |
|---|---|---|
| Solid plank floor (20 to 30 mm) | 6 mm or more | 6 to 10+ |
| Solid parquet (14 to 22 mm) | 4 to 6 mm | 4 to 7 |
| Engineered or veneer parquet | 0.6 to 4 mm | Depends on the remaining layer; do not sand at 2 mm or less |
| Thin veneer floor | under 0.6 mm | Do not sand the wood layer |
The figures are indicative and depend on how deeply the floor is sanded each time. The point remains: a solid wood floor can last for generations, while a thin veneer floor often only tolerates a single light refresh. If you want to know if your floor needs sanding yet, we have a guide on when a wood floor should be sanded.
Pine, oak, or hardwood: which wood can withstand the most sandings?
The type of wood matters less for the number of possible sandings (which is controlled by the thickness of the wear layer) and more for how the floor looks and behaves over time. Here are the three types we most often encounter in Danish homes:
Pine (pine plank floor)
A pine plank floor is soft softwood, often with prominent grain and knots, and the classic Danish flooring type in older houses and apartments. Pine is softer than oak, so it gets dents and marks faster, but it sands easily and quickly. A pine plank floor takes on a warm, golden tone when oiled and a light, almost white character when lye-treated. Because pine is soft, it requires a gentle hand on the machine so you don't sand grooves into the soft grain.
Oak
Oak is a hard, dense hardwood and the most popular choice for newer solid plank floors. It is more durable than pine, shows fewer marks, and has a calm, uniform grain pattern. Oak sands a bit slower because the wood is harder, but it provides a robust floor that withstands many years of use between each sanding.
Hardwood (exotic species)
Hardwood species such as mahogany, jatoba, or wenge are even denser and harder than oak. They are extremely durable but also more demanding to sand: they require sharp abrasive materials and experience, as some species contain oils and colorants that can react to the treatment. In return, a well-maintained hardwood floor is extremely durable.
| Wood type | Hardness | Sanding | Appearance |
|---|---|---|---|
| Pine | Soft | Quick, requires gentle hand | Warm golden colour with prominent grain |
| Oak | Hard | Slower, robust result | Calm, uniform, durable |
| Hardwood | Very hard | Demanding, requires experience | Dense, exotic, extreme durability |
Regardless of the wood type: the wider the plank, the more important correct machine guidance is. This brings us to the next challenge with wide planks.
How to sand wide planks without creating grooves?
Wide planks are beautiful but place greater demands on the sanding itself. A wide plank has more surface area that needs to be sanded uniformly, and any error in machine guidance becomes more visible. If you sand diagonally across a wide plank floor, or if the machine stops for a moment, grooves and depressions will appear, which become truly apparent only after the floor has been treated.
We always sand wide planks in the direction of the wood grain, never across, and keep the machine in constant, smooth motion. We work our way up through the grits, from coarse to fine, so that each step removes the traces of the previous one. On very uneven planks, the coarse step can be applied at a slight angle to remove the high spots before we straighten it again in the direction of the grain. This is the kind of routine that distinguishes a professional result from a DIY attempt.
Gaps, cracks, nail holes, and unevenness in old plank floors
When you need to sand an old wood floor, it's rarely just the surface that needs attention. Old plank floors have lived, and that means gaps and cracks between wide planks, old nail holes, cracks, and uneven boards. This is part of their charm but must be handled correctly before the finish is applied.
- Gaps and cracks between wide planks: wood expands and contracts with the seasons, and wide planks shrink and expand more than narrow ones. Smaller cracks are filled with a mixture of sanding dust from your own floor and binder, so the repair matches the colour of the wood. Large, continuous gaps are often deliberately left open because they belong to an old plank floor and partially close again in the summer.
- Nail holes and old screw holes: visible nail heads are hammered below the wood surface, and the holes are filled so that the sanding machine does not catch them and the surface becomes smooth.
- Uneven and raised boards: boards that have lifted at the edges are sanded flat, and loose or squeaky planks are screwed into the joists before we sand.
- Deep cracks: cracks that go through the plank are repaired with filler in the wood's colour so they don't collect dirt afterwards.
If you want to delve into the repair technique itself, we have an entire guide on mix and fill for cracks and holes, which describes how we make the repairs blend in with the wood.
Old plank floor and patina: what do we preserve?
An old plank floor carries the marks of decades of use: worn traffic routes, aged colour and small irregularities. Sanding balances a clean, sound surface with the character you want to retain. We discuss whether you want fresh bare wood or a lighter refresh that preserves more of the existing patina before work begins.
Treatment after sanding: should you sand and varnish, oil, or lye-treat the wood floor?
Once the plank floor is completely sanded clean, it needs to be protected. The treatment determines how the floor looks and lasts for many years, especially on a solid wood floor you want to enjoy for decades.
- Varnish: creates a hard film on top of the wood. Sanding and varnishing a wood floor provides a durable, easy-to-clean surface, but when the varnish wears, the entire floor must be re-sanded because you cannot spot-treat varnish.
- Oil: penetrates the wood and provides a natural, matt look that accentuates the grain in pine and oak. Oiled floors can be spot-treated locally in traffic areas without re-treating the entire floor.
- Lye: gives a light, Nordic look and prevents the yellowing that pine, in particular, gets over the years. Lye requires subsequent soap or oil and ongoing care with lye soap.
If you need to choose between the two most common, we have a thorough comparison of varnishing or oiling a wood floor. On an old pine plank floor, we often recommend oil or lye, as it complements the wood's lively grain better than a shiny varnish.
Can you sand a wood floor yourself, or should you hire a professional?
You can certainly rent a sanding machine yourself, and on a small, robust oak floor in good condition, a skilled DIY person can achieve a fine result. But on a wide plank floor, a soft pine floor, or an old floor with gaps, nail holes, and unevenness, there is a lot that can go wrong. Typical mistakes include grooves from a stationary machine, uneven colour, and sanding marks across the plank, which cannot be corrected without re-sanding the entire floor.
Because a solid plank floor only has a limited number of sandings in it, each sanding is too valuable to be spent on a learning process. A professional sands the floor uniformly, repairs damage correctly, and applies a durable finish so you get the most years out of each sanding. The cost depends on the floor area, wood type, and the condition of the floor, and we always provide a fixed price without surprises before we start.
Ready to sand your plank floor?
At Øens HåndværkerCentral, we sand solid wood floors and wide plank floors across the country and always assess the floor before providing a fixed price without surprises. Send us a few pictures of your plank floor and the floor area, or call us at 20 98 88 11, and you'll hear from us within 24 hours with a concrete offer.
Get a non-binding offer for floor sanding here.
Frequently Asked Questions
How many times can a plank floor be sanded?
A solid plank floor with enough wood above the tongue-and-groove joint may allow 6 to 10 full sandings or more over its lifetime. Each full sanding typically removes around 0.5 to 1 mm. The entire board thickness is not available for sanding, so the remaining usable wood must be measured. Engineered flooring usually allows fewer sandings.
Can you sand a wood floor yourself?
Yes, you can rent a sanding machine and sand a wood floor yourself, but on wide planks, soft pine, or an old floor with gaps and unevenness, there is a high risk of grooves and uneven colour. Because a solid floor only has a limited number of sandings in it, we recommend hiring a professional.
How much does it cost to sand a wood floor?
The quotation depends on the area, floor condition and any additional work. Standard sanding with a standard finish costs 175 kr per m2 including VAT from 36 m2; smaller jobs start at 3.700 kr. Standard oil and lacquer share the same base rate. Send photographs and the area for a fixed quotation, with a reply within 24 hours.
How are wide planks sanded without creating grooves?
Wide planks are always sanded in the direction of the wood grain with the machine in constant, smooth motion, never across or stationary. We work our way up through the grits from coarse to fine, so each step removes the traces of the previous one. It is the smooth machine guidance that keeps the surface free of grooves.
Which wood tolerates the most sandings: pine, oak, or hardwood?
The number of sandings is determined by the wear layer thickness, not the wood type, so a solid floor in pine, oak, and hardwood can be sanded many times. Oak and hardwood are harder and more durable between sandings, while pine is softer, sands faster, and requires a steady hand to avoid grooves.
We operate nationwide, but most of our flooring projects are in Eastern Jutland and the capital area. Learn more about floor sanding in Aarhus or floor sanding in Copenhagen, and get a fixed price for your project.