How To Fix Gaps In Hardwood Floor After Installation

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Gaps in hardwood after installation is no unusual occurrence. This may happen for many reasons, including temperature and humidity changes. Nature can wreak havoc on your hardwood in the form of rising and falling humidity levels. Unlike laminate, hardwood flooring is natural and hence is affected by the weather. It contracts and expands over time which creates these gaps.

If they are not compactly laid out in the first place, that might also lead them to fall apart. Another factor that results in gaps in hardwood is waterlogging. The problem arises when the water dries up after a while. The hardwood swells and then shrinks when the moisture content decreases. These gaps may also occur if the hardwood is subjected to dry heat from below, like from a furnace room.

The point to note here is that this swelling and shrinking will take place even on good quality hardwood floors or a proper installation job. Tackling these gaps is more than fixing how unsightly they look. They may pose a slipping or tripping hazard if the hardwood planks start to curl or buckle up. These gaps also attract dirt and debris, which ruins the look of the lovely hardwood floor. We got you covered! This is a guide to the most efficient way on how to fix gaps in hardwood floors after installation.

What causes gaps in hardwood floors?

Gaps are mainly caused by fluctuations in the weather conditions and rise and fall in humidity levels. Being a natural material, wood absorbs moisture in high humid conditions and shrinks during the dry or winter season. This expansion and contraction of wood lead to formation leading to the formation of gaps between adjoining boards.

Other causes may be improper fitting or installation.

Water damage is another prominent cause of gaps. Waterlogged wood swells and then shrinks upon losing moisture during dry conditions.

Ways to prevent gaps in hardwood floors

Proper installation: Always use the services of a trusted, professional installer for installing hardwood floors in your house. Poorly fitted boards are more likely to separate and develop gaps.

If the individual boards have been placed very close to each other, it increases the severity of the problems. When the planks expand in humid seasons, they are forced to curl or bow due to extra space’s unavailability, maximizing tripping chances.

Humidity level test: Conduct a test to determine humidity levels in the area you live. Use the results to decide which flooring option will be best suitable for your house.

Acclimatization of floorboards: It is essential to allow the planks to acclimatize to your house’s weather conditions before installing. Keep unwrapped wood planks undisturbed for seven to ten days.

If your home has highly fluctuating levels of humidity, consider adding a humidifier into your home.

How to fix gaps in Hardwood Floors After Installation?

Things you need to keep in mind before beginning the repair work:

Not all gaps pose a threat to your flooring. Wood is a natural product, so it’s very typical to expand and contract weather fluctuations.

Whether you need to worry or not depends on the duration for which the gaps are visible, the size of gaps, and the season in which you notice the gaps.

Pay close attention to when you notice the gaps; if the gaps are visible during the dry or winter season and close on their own during the humid months, there is no need to panic over them. Filling these gaps might be more of a problem since the planks will expand again in humid months and due to the unavailability of space, the floor might buckle or curl.

Humid seasons are the best time to check for gaps, as the planks are at their tightest fitting. You can ignore little gaps.

Once you have made sure that the gaps are not seasonal and present year-round, you need to repair them. Don’t delay in the repairing process as the situation may worsen with time. Moreover, there is a risk of house members tripping over it.

Which is the suitable time for repairing?

If the gaps are present at inconspicuous places or don’t post such a severe threat, we recommend fixing those gaps during the humid season.

The humid season is the best time because planks are swollen and tight and therefore leave narrow gaps. So once you fill them, you might have to witness slight cracks developing again in the next dry season. But this is somehow still better than leaving no room for them to expand.

Steps: Fix Gaps In Hardwood Floor After Installation

Should You Fill Them?

This question must be your starting point before going to fill these gaps. As we mentioned earlier, wood is a natural material and hence reacts to weather changes. If you notice a lot of gaps around the dry winter months but not so much during the more humid months, it wouldn’t be wise to fill the gaps. When the wood expands after the winters, the filling will prevent it from expanding as it would, which could lead to buckling or curling up of the hardwood.

So when should you fill them? Notice the gaps in the hardwood carefully during the humid season when they are packed the closest because of expansion. See whether the planks are still spaced out and if a nickel can slip inside the gaps. These are indicators of gaps that need your immediate attention and also give you a sense of whether they stay throughout the year. It is appropriate to fill them during the expanded phase, so when they expand after a cycle of winter contraction, the gaps are filled.

Materials/Tools You Will Need

  • Measuring Tape
  • Matching Hardwood
  • Wood Glue
  • Table Saw
  • Miter Saw Or Handsaw
  • Hammer
  • Sandpaper
  • Wood Stain

Repairing Gaps In Hardwood After Installation

Seasonal changes in hardwood and the subsequent gaps in the winter months shouldn’t bother you to fill them as they are bound to expand. This will only add to the problem and leave no space for the inevitable expansion of hardwood when it is more humid. Once you are sure that the gaps are permanent, choose a method of filling them that fits your bill. It never hurts to be doubly sure and call a professional woodworker or carpenter to check it out.

There are quite a few ways to fix gaps in the hardwood floor. One of the more conventional ways is to “fill” the gaps with matching hardwood strips, putty, or rope and then finish it off with the wood stain. Alternatively, if you feel the gaps have become too wide for filling and could use a total revamp, you can replace the entire flooring.

The latter is a more expensive method and should only be your last resort. Using fillers like wood strips and rope are affordable and the best options to fill narrow gaps in hardwood. We have decoded, fixing gaps in hardwood floor after installation using wood strips.

Using Wood Strips

fill holes in hardwood floor

You would require a table saw to fill gaps using wood strips. You would have to make rip cuts from spare matching hardwood floorboards using it. If you do not find the exact same hardwood, go for the one that matches the existing flooring the most. This method could be a little tedious but gives a very satisfactory result.

Step 1: Cutting The Wood Strips

Begin by measuring the gaps in the hardwood. After you have the required length and width of the spare hardwood strips to be made, go ahead and make the cuts using a miter or handsaw. Be extremely careful as it is quite dangerous making rip cuts on a table saw, and do not hesitate to seek help from someone to do it.

It is always wise to cut from the grooved side of the floorboard so that the depth of the strip will fit perfectly with the tongue of the existing hardwood. This is all the more crucial if you plan to use the tongue and groove flooring system.

Step 2: Glue Them

Use only the special wood glue or sealant for this step. After you have measured and cut the strips accordingly, apply the wood glue on the edges of each strip deliberately. Then gently lower these into position and tap in place using a hammer.

Try and match the grain of the adjoining hardwood to get a seamless look. Once you know the strip is firmly in place, wipe away any residual wood glue with a cloth. Allow it to dry, and please do not rush this part. The strips need to dry completely so that they are more durable.

Step 3: Sand And Stain

This second last step is to ensure the rest of the floor and the wood strips that were added later do not look separate from each other. Use sandpaper for sanding any uneven areas. This will require a significant amount of precision, so you don’t damage the finish of the adjoining boards. The final step is to use a wood stain or finish to get the strips to match the rest of the floor perfectly.

By Using Wood Putty or Wood Fillers

wood putty and wood filler

Wood putty or fillers are the quickest and easiest method to fill small gaps.

Clean the flooring using a dry or slightly wet cloth.

Take a considerable amount of wood putty and put it into the gap.

Use your fingers or a putty knife to force it into the gap.

Remove the excess amount of putty. Try to find a shade of putty that best matches your flooring, or you can also mix different colors to get the desired shade.

Let it dry completely by leaving it undisturbed for a few hours.

After that, you can apply a coating of surface finish or paste wax for extra strength and a better finish.

Wood putty or wood fillers?

While many of you think that they are the same, it’s slightly misleading to use both terms interchangeably.

Wood putty generally contains urethane, polyurethane, or epoxy and is flexible and pliable even after drying. They are usually used to fill small gaps. They are available in many different shades.

Whereas, Wood fillers are made of wood by-products like wood dust or sawdust that get rock hard once they dry up.

Wood fillers generally come in a tube with a pointed nozzle.

Take some on your fingers and work your way along with the gaps.

Put the wood filler into the gap, use circular motions and press down to ensure that filler goes into the opening, Let it dry. After that, use a soft cloth to wipe off the excess amount of filler. Once it dries, sand it to remove any uneven finish.

Apply the desired finishing of urethane on it.

While using wood putty or wood fillers, make sure you do not stain adjoining floorboards. For that, use two broad tapes on each side of the gap.

Also, wear rubber gloves as wood fillers tend to dry quickly and can stick on your hands.

If there are several gaps using wood putty can ruin the look.

For more gaps, refer to the methods given below.

By Using Ropes

how to fix gaps between wooden floors

Repairing gaps using rope is an age-old tradition. Make sure you always use a natural fiber rope like cotton or jute rope as they absorb the stain better.

Clean the gaps: Remove any dust or traces of old putty. Use a vacuum cleaner in case of any loose debris. You can also use a scraper.

After measuring the gap, take a rope with a slightly bigger diameter.

Stain the rope: Take a matching shade of wood stain into a bucket and dip the rope into it.

After the rope absorbs the stain properly, pull it out carefully.

Drain excess stain and then stretch the rope properly over a paper and let it dry completely.

After the rope is dried, apply a small amount of wood glue in the gap before placing the rope into it.

Put the rope evenly in the gap using a putty knife or fingers.

Ensure that the rope is flush with the wood surface. Cut or trim any extra rope as per the requirement.

After the glue dries, you can add a urethane surface finish to it.

If the gaps between the boards are huge, you will not be able to fix them. Consider using an expert’s service to repair those gaps.

How Can You Prevent Gaps In Hardwood Floor

As is well known, prevention is better than cure. We will discuss ways to prevent having to tackle gaps in a hardwood floor after installation, as that is a trickier problem to solve. Careful planning should ideally begin at the initial stage when you start hunting for the ideal hardwood for your floor. The most important step involved in this is acclimatization of the hardwood you decide on.

Conduct a humidity test by leaving one hardwood plank out of its packaging for at least ten days. Changes in humidity levels can cause the hardwood floor to split or warp. Despite not being as long as it takes for the gaps actually to develop (they may take years to surface), this test will still help you get a fair idea of the hardwood’s capabilities. If you realize that the air in your house is dry, getting a dehumidifier may also help minimize the possibilities of gaps in the hardwood floor after installation.


Gaps in hardwood floors are inevitable and are just a result of wood being natural and hence is affected by the effects of weather changes. There is no need to fret over this. Simply figure out whether these gaps are permanent and require filling. If yes, see if you can fill the gaps using wood strips and seek professional assistance if you need to. This guide on how to fix gaps in hardwood floors after installation will help you get over this without any qualm!

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