What causes warped wood floors, and How to fix it?

Wood floors can deform and warp, which can happen quickly or over time. In any case, it shows that something is wrong.

In technical terms, this deformation, called “buckled,” is almost always caused by the same things.

Wood responds to the amount of moisture in the air, the substrate, etc. If there isn’t enough room, it changes shape to a greater or lesser degree.

Preparing the substrate and determining how much it will grow is very important. It is possible to fix. But, like all work, there are rules about how it can be done.

The most important thing to do is to get rid of the problem’s cause. If this point is not considered, the wood floor will almost certainly keep getting bent.

So, you must fix what’s wrong instead of covering up the flaws.

Causes of warped wood floors

warped or buckled wood floors due to water and moisture are the enemy of all wood floors, whether glued down or floating.

This is the moisture under the floor, not the moisture on top! Wet subfloors cause about 85% of the damage to wood floors.

There are many different kinds and sources of water. So, it can be challenging to figure out what’s happening.

Residual moisture

Residual moisture is a problem when the subfloor is touched with a screed about 15 days after putting down the new wood floors.

With screed, the subfloor is leveled so the floorboards can be laid best. But with screed, you have to think about how long it will take to dry, depending on ventilation, how warm the room is, etc.

Moisture left behind can only show up after some time has passed. In June, when the weather is nicest in the summer, you put down your floating wood floors on a subfloor that looks fine.

If you turn on the heat in October, the subfloor may release any remaining moisture through the wood floors, which could cause the new floor to warp. But you can avoid this problem by using a moisture meter to check the floor before laying it.

Professionals always have this tool with them and must check the subfloor before laying the floor. The subfloor must have less than 3% of water in it.

Are you running late? In this case, you might change the shape of your wood floors! If there’s still moisture in the subfloor, it will go through the wood floors and out the door. Your new floor will get damaged and warp a little or a lot.

Moisture in the subfloor

Subfloor moisture, like residual moisture, doesn’t just affect new buildings. For instance, moisture can rise from a basement without anyone noticing, but it won’t hurt other floor coverings.

On a new traditional substrate, like a cement screed, give it at least 1 mm daily to dry.

So, if you have a substrate that is 10 cm thick, you must wait at least 100 days unless you speed up the drying process. But you still need to check with a moisture meter before laying.

If you don’t, there’s a good chance that your wooden floor will get wet and warp over time.

It’s easy to stop this from happening. Before putting down the floor, you must check the subfloor for moisture. It must be less than 3%. If this is not the case, you should wait to lay it.

You should also treat the base to keep the water in for good. To do this, you need to get basic treatment.

A vapor barrier is always put down under wood floors. But this doesn’t stop enough water from getting in. Before putting down the wood floors, the subfloor must be sealed to keep out moisture.

water damage

Warped wood floor due to water and your wooden floor is getting wet from above. When water damage to wood floors happens, it usually pools on the floor and soaks it.

The floor only buckles when the water dries up. Of course, the risk of deformation goes down as the size of the puddle goes down.

So, to figure out how bad the damage is, you need to wait until the wood floors are completely dry. These can be changed if the damage is limited to just a few planks.

Dry and humid air

The shape of your wood floors can also be changed by air that is too dry or too wet.

Even though a floating wood floor is more stable than one glued down, it can still warp in humid conditions.

But in our latitudes, deformation from too much humidity doesn’t happen very often. Instead, air with less than 30% humidity throws off the balance of our floors. Most of the time, heating and cooling is to blame.

Once you know what’s wrong, it’s usually enough to change the humidity in the room for the wood floors to return to their original shape. But this solution will only work if your wood floors have not warped too much.

It would be best if you had an ideal moisture level in wood flooring, and the humidity should be between 45 and 65%.

Missing expansion joints

The floating wood floors can’t stretch enough, which is another reason it bends. The wood floors can’t touch any of the other parts.

It must have enough room to grow on its own. For this, you must know how far away the wall is. These so-called expansion joints have to be at least 8 mm wide.

There must be expansion joints everywhere: around the door frames, on each wall, around the heating pipes, where one-floor covering meets another, and pretty much anywhere there is a problem.

Putting in a floor without expansion joints is a big mistake. In this case, the wood floors are pushed up against the obstacle.

Just one point is enough to make the whole floor warp. When this happens, your wood floors turn wavy.

How to fix warped wood floors?

It is possible to repair a floating wood floor that is warping. However, repairs are often expensive.

You can only make your floor shine like new once you find and fix the problem. Only some things need to be changed. The best thing about wood floors is that they can be fixed if damaged.

Easy sanding

A light sanding might be enough if the floor is slightly out of deformation. But keep in mind that you will need to treat the floor afterward. If the floor is stained, it can be challenging.

Heavy sanding

If the floor is crooked, sometimes the only way to fix it is to sand it hard. If your wood floor has an angle, it will, unfortunately, disappear if you sand it too much.

Doing this will take away about 1 to 2 mm of wood, the depth of an angle.

Once the deformation is gone, you can protect the wood floor by re-oiling or varnishing it. You can now also change the color of your floor if you want to.

Not enough distance to the wall

If your wood floors are curved because they are too close to the wall, it is often enough to put expansion joints where the planks touch an object.

After that, the floor will probably return to how it was before. So, you’ll have to cut expansion joints in your floor so that it’s at least 8 mm from the wall.

Less damage will be done to your wood floor if these expansion joints are cut as quickly as possible.

Replace Floorboard

If your floor has too much cupping, the planks will bend so much that they will break. In this case, the wood floor has to be replaced all the way through.

Final Thought

A wood floor won’t warp if you take a few simple steps. If you don’t want your wood floor to buckle, it should be laid according to the rules of the art.

It is important to check the subfloor. If a professional puts in your floor, ensure you get proof of a soil moisture test before you start working.