Have you noticed gaps appearing between the boards of your wooden floor? This is a fairly common problem, especially in homes with old floors or during seasonal changes in humidity. Wood is a living material; it reacts naturally to dry air by shrinking slightly.
The good news is that in most cases, the situation can be remedied, and it is not necessary to immediately undertake expensive repairs with replacement of the entire covering. There are several proven ways to help restore the floor to its neat appearance and get rid of drafts and dust that come through these cracks.
Let's figure out what exactly caused the gaps to appear and what repair methods will be most effective. The choice of solution largely depends on the size of the gaps, the type of floor, and your future plans for its finish.
Why does wood dry out?
Wood is hygroscopic—it absorbs and releases moisture depending on the environment. In summer, the humidity in an apartment is 50-60%, and the wood absorbs moisture and expands slightly. In winter, when the radiators are on, the humidity drops to 20-30%, and the boards release moisture and shrink.
A single 100 mm wide board can shrink by 2-3 mm when the humidity changes from 60% to 20%. If there are ten such boards per meter of floor, this results in a total of 20-30 mm of gaps. They are distributed unevenly — somewhere the gap is 1 mm, somewhere 5 mm.
This is not a defect or poor wood quality. It is physics. Even expensive oak or ash parquet will dry out at low humidity. Softwoods — pine, spruce — are more stable, but they also react to changes in the microclimate.
Old wooden floors dry out more than new ones. Over decades, the wood goes through dozens of expansion-contraction cycles, the fibers weaken, and the boards become less elastic. Plus, over time, some of the natural resins that retain moisture are lost.
If the floor has been laid for more than 20-30 years, gaps will appear every winter, and they may become slightly wider each year. This is a normal process of material aging.
Wood floors can dry out over time and develop gaps — this is normal, especially in homes with humidity fluctuations. The good news is that in most cases, this can be fixed without completely replacing the flooring. Small gaps can be filled with special compounds — paste or resin that is similar in color to the wood. If the gaps are larger, moistening sometimes helps — the wood expands slightly and the gaps become smaller. In difficult cases, it may be necessary to replace individual boards or sand the floor. The main thing is not to delay, so that the problem does not get worse.
What definitely does not work
- Fill the gaps with wood filler. In the spring, the boards will expand, and the filler will be pushed out or crumble. In a month or two, there will be no trace of your efforts. Plus, the filler is usually lighter or darker than the wood, so it looks like a patch.
- Fill the gaps with sealant or silicone. The same story — in spring, the wood expands, the sealant is squeezed out, and unsightly drips remain on the surface. It is difficult to remove them later, as the silicone eats into the wood.
- Tighten the boards by mechanically removing the gaps. Theoretically, you can dismantle the floor and lay the boards more tightly. In practice, this is a huge job, after which the boards will expand again in the spring, press against each other, and begin to bend into an arc. The floor will become uneven, and the boards may crack.
- Cover the floor with a thick layer of varnish in the hope of sealing the wood. Varnish creates a film on the surface, but does not completely stop moisture exchange. The wood still breathes, only more slowly. The gaps will become slightly smaller, but will not disappear.
Effective methods for sealing gaps
For gaps up to 3 mm — wood dust with PVA glue. Mix fine wood dust (which can be obtained by sanding) with PVA glue to form a thick paste. Fill the cracks with a spatula and tamp down. It dries in a day. It holds better than ready-made putty because the paste is made from the same wood and moves with the boards.
In spring, when the boards expand, this mixture will shrink along with them. It will not fall out completely, but it may settle slightly. It will need to be renewed once a year.
For gaps of 3-5 mm, use wooden inserts. Cut wedges out of thin slats or plywood, coat them with glue, and hammer them into the gaps. Cut off the excess with a chisel and sand it down. It will be almost invisible if you choose wood that matches the color.
The inserts should be slightly wider than the gap so that they fit tightly. But don't overdo it — if you insert a slat that is too thick, it will expand in the spring when the boards expand and may lift the boards.
For gaps larger than 5 mm, use a special sealing cord. This is a round polymer cord that is packed into the gap using a blunt spatula. You can apply wood-colored sealant on top or leave it as is.
The cord is elastic, contracting and expanding along with the wood. It does not fall out or crumble. It is sold in hardware stores and costs from 50 rubles per meter. It comes in different diameters — choose one that matches the width of the gap.
How to reduce drying out
The main method is to maintain air humidity at 40-60% all year round. At this humidity, the wood remains stable, with minimal dimensional fluctuations.
A humidifier in winter is not a luxury, but a necessity for wooden floors. Even a simple ultrasonic humidifier costing 3-5 thousand rubles can radically change the situation. Turn it on at the beginning of the heating season, and the gaps will either not appear at all or become insignificant.
You can do without buying equipment — place containers of water on the radiators, hang wet towels, and wet clean more often. This is less effective, but it also works. The main thing is consistency; you need to do this all winter.
You can check the humidity with a hygrometer. It costs 300-500 rubles and shows the current humidity in the room. If you see 25-30%, this is critically low for both the floor and your health (dry air dries out the mucous membranes and lowers immunity).
Do not place furniture close to the walls above the radiators. This is where the air is driest and hottest, and wood in these areas dries out the most. If the furniture has been there for a long time, look at the floor underneath it — most likely, the gaps are wider there.
When major floor repairs are needed
If the gaps are so wide that you can see the floor below. This is no longer a cosmetic problem. Such gaps mean that the boards have lost a significant part of their volume, possibly due to rot or fungus. An inspection is needed — remove a few boards, check the joists, and assess the condition.
If the floor creaks in most places. Creaking is a sign that the boards are loose, possibly because the joists or underlayment are worn out. Simply filling the gaps will not solve the problem; the structure needs to be reinforced.
If the boards bend when you walk on them, it is dangerous—it may mean that the joists are rotten or cracked. Walking on such a floor is risky; you could fall through. The supporting elements need to be dismantled and replaced.
If you see mold in the cracks or smell a musty odor, it means that there is moisture under the floor and the wood has started to rot. It is pointless to fill the cracks; first, you need to eliminate the source of moisture and treat the wood with antiseptics.
In these cases, filling cracks is like applying cosmetics to a diseased tooth. The problem is deeper, and postponing repairs is dangerous.
As you can see, gaps in wooden floors are usually not a death sentence, but a solvable problem. In most cases, you can fix the situation yourself by choosing a method that suits the size of the gaps and your skills.
The main thing is to correctly assess the scale. Small cracks can be easily filled with putty or sealant. For medium-sized gaps, cord or thin slats are ideal. And if the floor is uneven and the gaps are very wide, it may be worth considering sanding the entire surface.
Don't forget that wood is a living material. After any repairs, try to maintain a stable humidity level in the room. This will help the floor retain its shape and prevent it from drying out again. Good luck with your repairs!
