How to Use Wood Filler on Hardwood Floors to Fill Up Gaps

How to Use Wood Filler on Hardwood Floors

The beauty of a true hardwood floor is undeniable and more people are finding it classy for their home recently. With right preservation, your home can rock the hardwood concept certainly.

However, with beauty, you also get to deal with a lot of problems. One such issue is discovering gaps in your hardwood floor. Those formed cracks are enough to ruin the whole look and we don’t want that.

As an easy and most used solution, people look for methods on how to use wood filler on hardwood floors to fill up those gaps. You can try purchased filler or the DIY version. We also have a complete breakdown of how to make wood filler for hardwood floors.

Discussing How to Fix Gaps in Hardwood Floors with Wood Filler

We will be talking from the start to end on how you can utilize wood filler for filling those gaps and get things sorted easily. Let’s Jump into The Entire Process.

Tools That You Will Need

1. Wood stain
2. Some paint
3. Putty knife
4. Tack cloth
5. Sealer (polyurethane)
6. Sandpaper
7. Shop vacuum
8. Your chosen wood filler

Pick the Right Wood Filler

Depending on your circumstances, you need to pick a suitable wood filler for the job. There are quite a few types to pick from. If you want a filler that will be receptive to staining, then go for stainable wood fillers. After using this type of wood filler, you can easily stain over it. And that will ensure the section you just repaired is matching with entire piece.

Now for applications such as molding, cabinetry, and paneling, you should consider water-based wood filler. These work best in indoor situations. These are also good with staining or painting requirements.

And finally, if you need something for outdoor use that will provide best results with trim and exterior siding, then solid solvent-based wood fillers are your go-to option. After deciding on the appropriate wood filler, move on to next step.

The Repair Needing Hardwood Surface Must Be Clean & Sanded Properly

On the surface where you will be applying wood filler, perform a few preparatory steps to ensure better results. And this includes getting rid of any noticeable loose wooden chunks or flaking points.

You want to deal with those rough edges as well. Sanding is the best solution to do so. Next use any shop vac to simply get rid of all those lingering dust and debris. A damp tack cloth will also work here. However, in the latter case, you should also wait for it to dry properly before proceeding ahead. A 36 grit will help you with proper sanding.

Application of Filler with Putty Knife Gradually

You need to begin with the area that has damaged. Gentle press filler into the depression. The filler might shrink as it dries. So, you should slightly overfill it but not too much. Gradually apply the filler as much as necessary. Now use a clean putty knife to smooth out the filled area nicely. This will provide an even result that will hardly look like you’ve repaired it.

Let the Filler Dry Completely

Depending on what wood filler you are using, the time necessary to dry it will vary. You should refer to the manufacturer’s recommendations for this. There should be some mentioning of the appropriate time necessary for drying. However, based on the depth of application, this drying period can be somewhere between 15 minutes to 8 hours.

Final Sanding to Match the Surrounding Wood Height

As soon as filler dries completely you may notice some unevenness with height compared to the surrounding wood area. This is pretty normal and can be sorted through sanding once again.

Try running your hand over the filled area as well as surrounding undamaged parts. It should feel very slightly uneven not too much. Sanding very carefully with a gradual hand will sort the problem.

Apply A Finish of Your Choice

Now once you are done with main repair part, you’ll want to make the fact that it is been repaired less obvious. And to do so, you need some paint or floor finish matching to the undamaged part. Through this concealing hack, you can easily hide the fact that there was ever damage in this filled area.

Here you should know the right way on how to use stainable wood filler as well as applying stain following to that. However, staining can be a bit tricky for the first-timers. One good method is using a random piece of scrap wood to dab filler onto it. Let the filler dry and then you can stain to see if things match together or not.

Depending on outcome, you can decide whether to thin out the stain or go for another shade. And if odds are in your favor, then the stain will match close enough for a cheap, easy and fast fix next.

Critical Points on Filling gaps in Hardwood Floors That You Must Know!

There are a few points that you should know about hardwood floors and before trying any filler things to it. First of all, be aware of the fact that wood is supposed to expand and contract depending on seasonal humidity changes. Are you seeing the gaps during the dry winter months? But also, there are not many noticeable gaps during humid seasons?

If you are answering both questions yes, then it’s best to leave it alone. This is because when you decide to fill the gaps on its widest condition, with expansion this will bring further problems later. In worse cases, with no room left for expansion, it can buckle as well.

If the case is about filling gaps in old wood floors, then know that those developed gaps can be more or less constant. While there’s still a chance of becoming narrower or wider because of humidity changes here.

The best way to be sure here is to check flooring during humid season. This is when the wood will be most swollen. If you believe that these gaps are enough big to hold a standing nickel inside, then there’s a problem and it needs some correction.  Also, if you believe that the gaps are existing for year-round, things are probably safe to try filling.


And that was basically everything about how to use wood filler on hardwood floors. Here’s a quick note we want you to know. Wood fillers are no permanent fix. With the expansion and contraction, its effectivity will get compromised.

And the only savior to hold it is maintaining proper humidity. Also, fillers won’t be the best solution for huge gaps. So be sure you are expectations are not beyond what a wood filler can provide. Also, that does not make the wood filler a less helpful solution by any means. It’s just that you need to be in touch with the hardwood’s maintenance frequently as well.

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