How to Fix Gaps in Hardwood Floors: Easy DIY Guide

Gaps in hardwood floors result from various factors, including incorrect installation, age-related wear and tear, or natural expansion and contraction of the wood due to shifts in humidity. Repairing hardwood floor gaps is a straightforward DIY project that requires a few tools and materials.

Wood floor gaps


Preparing for Repair

Inspect and Measure the Gaps

Begin by measuring the width, length, and depth of the gaps. These measurements will determine the best method and materials for filling the gaps.

Also, assess the condition of the surrounding floorboards. Look for signs of damage or shifts that may need attention during the repair process. 

If there are a lot of gaps in your floors, don’t use one of these DIY methods. Filling cracks with wood filler or caulk is best when there are only one or two gaps in the floor. If there are several gaps, look into floor replacement.

Ensure Proper Ventilation of the Work Area

When using chemicals or finishes emitting fumes, ensure proper ventilation in your work area. Open windows, use fans or work in a well-ventilated environment to minimize fume exposure.

Repair Narrow Gaps in Hardwoods with Wood Filler

Start by selecting high-quality wood filler designed for hardwood floors. Choose a filler that matches your floor’s color or allows staining for a matching look.

1. Clean the Gaps and Surrounding Areas

Ensure gaps and the surrounding area are free of dust, debris, and loose wood pieces. Thoroughly clean gaps using a vacuum cleaner, broom, or damp cloth to ensure better filler adhesion.

2. Apply Wood Filler

Follow the manufacturer’s instructions when preparing the wood filler. Mix or knead the filler until it reaches a workable consistency. Mix only the amount needed for the repair to avoid waste.

Using a putty knife or scraper, insert the wood filler into the gaps, ensuring complete coverage and slight overfilling.

3. Smooth the Filler

Use the putty knife to clear the filler’s surface, leveling it with the surrounding floor. Work in small sections, as the filler may dry quickly.

Gently wipe away excess filler using a clean cloth or sponge to avoid disturbing the filled gaps. Pay attention to the edges of the filled gaps for a clean finish.

4. Allow the Filler to Dry

Allow the wood filler to dry according to the manufacturer’s instructions. Drying takes a few hours, depending on the product and environmental conditions. Avoid walking on the repaired areas until the filler cures.

5. Sand the Filled Area

Once the filler is dry, use fine-grit sandpaper or a sanding block to smooth the filled gaps. Sand in the direction of the wood grain to blend the filled areas with the floor. Avoid damaging the surrounding floorboards.

6. Apply a Matching Finish

If necessary, apply a matching stain to blend the filled gaps with the rest of the floor. Allow the stain to dry before applying a protective finish for a consistent appearance and wood protection.

Repair Wide Gaps with Caulk

Caulk is the best remedy for repairing wide gaps — but it’s not a good choice if you have lots of cracks, as the caulk WILL be noticeable. Choose high-quality, paintable caulk suitable for hardwood floors. Select a caulk color that matches or complements your existing floor color.

Here’s a step-by-step guide for repairing wider gaps using caulk:

1. Clean the Gaps

Ensure gaps and the surrounding area are clean. Check for debris, dust, or loose wood pieces. Clean gaps using a vacuum cleaner, broom, or damp cloth.

2. Apply Caulk Using a Caulk Gun

Hold the caulk gun at a 45-degree angle. Squeeze the trigger to apply caulk into the gap, starting at one end and moving along its length. Fill the entire gap, allowing slight overfill.

3. Smooth the Caulk With a Putty Knife

Use a putty knife to smooth the caulk surface, leveling it with the surrounding floor. Work in small sections to prevent the caulk from drying before you can smooth it.

Gently wipe away excess caulk from the floor’s surface using a clean cloth or sponge. Make sure not to tamper with the caulk in the gaps.

4. Allow the Caulk to Dry

Follow the manufacturer’s instructions for drying time. Avoid walking on the repaired areas until the caulk cures.

5. Sand the Caulked Area Lightly

If the caulk surface appears uneven after drying, lightly sand it with fine-grit sandpaper or a sanding block. Sand in the direction of the wood grain, and be careful not to damage the surrounding floor.

6. Apply a Matching Finish

Depending on your desired outcome, apply stain and finish if needed. Apply the finish to the entire floor and blend the repaired gaps with the rest. This ensures a consistent appearance.