How to Fill Gaps in Laminate Flooring Like a Pro: Practical Steps, Tools, and Tips to Restore Seamless Laminate Floors

Laminate flooring is loved for its modern look, easy install, and its durability. Yet even the best-laid floors can develop small gaps over time. These gaps aren’t just unsightly—they can let water in, start to harbor dirt, and even trip you up when walking barefoot. The good news? You don’t need to call a contractor every time a gap appears. Whether the problem popped up due to shifting, seasonal humidity changes, or minor installation issues, you can fix most gaps in laminate flooring yourself with a few tried-and-true methods.

If you’ve ever wondered how to fill gaps in laminate flooring without replacing the planks or breaking the bank, you’re not alone. I’ve run into this countless times in both my own projects and with clients. Let’s walk through practical solutions, what causes these gaps, and how to keep your floors looking flawless.

Plan Before Filling: Understanding Flooring Gaps

Before you leap into repairing the gaps, it’s useful to know why they appeared. In my experience, most gaps are due to:

1. Seasonal expansion and contraction: Laminate, like all wood-based products, expands when humid and contracts when dry.
2. Poor subfloor preparation: High and low spots can stress joints over time.
3. Incorrect installation: Not leaving the recommended expansion gap at the edges, or not clicking the planks together fully.

Once you identify the likely cause, you can not only fix today’s gaps, but help prevent them in the future. When I remodeled a craftsman-style home in Boston, most of the floor gaps were seasonal—so we paid special attention to humidity control and making tiny adjustments instead of major repairs.

Choose the Right Tools for the Job

You don't need fancy equipment—just patience, technique, and a few essentials:

1. Laminate floor gap fixer kit or "floor gap fixer" block
2. Rubber mallet
3. Laminated wood glue (for permanent, non-movable planks only)
4. Color-matched laminate filler or putty (for very small gaps or cracks)
5. Vacuum/broom and a clean cloth

I commonly recommend a laminate floor gap fixer, which is a reusable device that uses a sticky pad and mallet to gently tap planks back together. For more intricate repairs, you’ll want some color-matched putty—these can be a lifesaver for hiding hairline cracks near walls or floor transitions.

How to Fill Laminate Floor Gaps: Step-by-Step Guide

1. Clean the floor thoroughly. Dirt and debris trapped between planks make any fix temporary. I always vacuum along the seams first.
2. Assess the gap size. Small gaps (under 1/8” or 3mm) usually just need putty. For larger gaps, a gap fixer block is more effective.
3. Bump the planks together. Place the block on the gapped plank and gently tap it toward the gap with a mallet. Never use excessive force—gentle taps do the trick. (See my story below for a misfire!)
4. Use putty or filler for small gaps. Squeeze a bit of color-matched laminate putty or caulk into small cracks. Wipe excess with a clean cloth before it dries.
5. (Optional) Apply glue for permanent repairs. If the plank is unlikely to move (near a wall or transition), apply wood glue and clamp carefully.

If you need a quick visual, here's a 2-minute video guide from my last client project (check out our DIY room decor tip gallery for more hands-on ideas).

Common Mistakes & How to Avoid Them

Fixing gaps seems simple, but I’ve seen a lot that go wrong! These are the most frequent mistakes to watch for:

1. Forcing planks too aggressively, which can break the click-lock and make problems worse. Always tap gently and check as you go.
2. Using the wrong filler: Avoid generic wood fillers, which may not flex with laminate and often look obvious. Buy a color-matched laminate putty.
3. Ignoring underlying issues: If a gap reappears after fixing, check for ongoing moisture or uneven subfloor.
4. Applying glue to floating floors: Don’t glue planks in the middle of a floating floor—this can affect the entire "floating" function and create more gaps down the line.

Case Study: Fixing Seasonal Gaps in a Family Room

One of my favorite stories: I helped a DIYer in Austin whose beautiful dark oak laminate started gapping every winter. Instead of filling each crack with putty, we invested in a small humidifier to maintain indoor humidity around 45%. Over the next few months, most of the gaps closed naturally. For the tiny remaining gaps, we used a matching putty and a soft cloth—problem solved, and the floor looks seamless once again.

FAQ

1. What causes gaps in laminate flooring?
2. Most often, gaps are due to changes in humidity, improper installation, or subfloor movement. Seasonal changes are the #1 culprit in many U.S. homes.
3. Will gaps in laminate close on their own?
4. In many cases, yes—especially if caused by dry winter air. Try using a humidifier and wait a season before attempting major repairs.
5. Can I use regular wood putty to fill the gaps?
6. It's better to use color-matched laminate putty, since it’s more flexible and adheres better to laminate surfaces.
7. How do I avoid gaps when installing new laminate flooring?
8. Carefully follow installation instructions, especially regarding subfloor prep and leaving the right edge expansion gap. Using a floor planning tool can help ensure precision from the start.
9. Should I replace a plank if the gap is too large?
10. If the gap is more than ¼ inch and can't be fixed by shifting planks, replacement may be your best bet.
11. Is it safe to glue laminate planks to fix gaps?
12. Only glue planks near room edges or transitions—never in the middle of a floating floor.
13. What’s the best tool for closing gaps?
14. A laminate floor gap fixer or tapping block with a rubber mallet prevents damage and offers the most control.
15. Are laminate floor gaps covered under warranty?
16. Check your manufacturer warranty. Most exclude damage due to humidity or improper installation, but it never hurts to ask.
17. How long does it take to fix a typical room?
18. For a standard living room, fixing small gaps can take less than an hour. Large projects or repeating problems could take longer, depending on the root cause.
19. Can gaps come back after fixing?
20. Yes, especially if caused by ongoing humidity swings. Try to stabilize indoor climate for best results.
21. What’s the risk if I ignore gaps?
22. Ignored gaps can allow moisture below the surface, potentially warping the floor or leading to further separation.
23. Are there free design tools to plan my next flooring project?
24. Yes—check out this free floor plan creator to visualize layouts before installing new floors or repairs!