How to Fix a Gap in Laminate Flooring
Gaps in laminate floors come from shifting planks, seasonal expansion, or installation errors. Three proven methods to close them, and which one to use for your specific gap.
Quick answer: To fix a gap in laminate flooring, first identify the cause, shifted planks (most common), seasonal expansion, or insufficient expansion gap at the walls. For shifted planks, use a pull bar hooked over the end of the row and tap with a hammer to slide it back into alignment. For small stable gaps, press color-matched laminate seam filler into the crack. Always use a tapping block, hitting the plank directly will damage the edge.
A gap in laminate flooring shows up out of nowhere, one day your floor was tight, the next there’s a visible line between two planks. Sometimes it’s seasonal expansion. Sometimes the planks have shifted. Sometimes it’s an installation defect that finally showed itself. The fix depends on the cause and the size of the gap, and most fixes are 15-minute jobs that don’t require removing planks.
I had a gap show up in our hallway in February of 2023. About a sixteenth of an inch, exactly where the floor runs past the laundry-room doorway. The pull bar I bought (a $9 ROBERTS one from Home Depot) and a rubber mallet closed it back up in about three minutes once I pulled the quarter-round trim. The gap hasn’t come back. Most laminate gaps are the same story: a plank that shifted, not a flooring problem.
What You’ll Need
- A rubber mallet or hammer + a tapping block (a scrap of wood or laminate)
- A pull bar (~$10, designed for floating floors)
- Wood filler matched to your floor color (for small permanent gaps)
- A putty knife
- Laminate seam filler (sold for this exact purpose)
- A clean rag
- A vacuum
Step 1: Identify Why the Gap Appeared
Different causes need different fixes.
Seasonal expansion gap
Floor planks contract slightly in dry winter air. If the gap appeared in winter and tightens up in summer, it’s seasonal, leave it alone or use a temporary filler. A humidifier in winter helps.
Planks shifted out of click-lock
The locking mechanism between planks can disengage if the floor was installed without proper expansion gap around the edges, or if heavy furniture was dragged across it. The planks need to be tapped back together.
Subfloor issue
If the gap appeared along with a high spot or low spot in the floor, the subfloor is uneven and the planks are flexing. Needs more than a quick fix.
Installation defect
The floor was installed too tightly to walls (no expansion gap) and is now buckling, creating gaps elsewhere. Needs the perimeter cut back.
Most gaps are #2, shifted planks, and that’s the easiest fix.
Method 1: Tap the Planks Back Together (For Shifted Planks)
The right method for the most common cause: planks that have separated at their joint.
Steps:
- Identify the gap and which planks shifted.
- Look at the end of the row, the gap usually traces back to a plank that needs to be slid back toward the wall on one end.
- From the wall side, use a pull bar hooked over the edge of the last plank, and tap the pull bar with a hammer. Each tap pushes the plank back into alignment with the rest of the row.
- If the gap is in the middle of a row, you may need to work from both ends, push one plank one direction while pulling another the other.
- Watch the gap close as you tap. Stop tapping the moment it’s flush.
Important: if you can’t access the end of the row without removing baseboards, take off the baseboards or quarter-round first. Trying to pull a plank without access to its edge will break the locking tab.
Method 2: Use Laminate Seam Filler (For Cosmetic Gaps)
If the gap is small and stable, not getting worse, but you can’t or don’t want to tap planks back together, a color-matched filler closes the gap cosmetically.
Steps:
- Vacuum the gap thoroughly.
- Match your filler to the floor color. Several brands make laminate-specific seam fillers (UniRepair, Konecto, color-matched putty sticks).
- Press filler into the gap with your finger or a putty knife.
- Wipe excess immediately with a damp rag.
- Let cure per package instructions.
A cosmetic fix only, it doesn’t lock the planks together. But for a small stable gap, it makes it invisible.
Method 3: Reinstall (For Severe Cases)
If multiple planks have shifted, the floor is buckling along an edge, or a plank is damaged and needs to come out (water leaks under appliances are a common cause):
- Remove the baseboard or quarter-round along the affected wall.
- Check the expansion gap between the laminate and the wall, it should be 1/4 to 1/2 inch on all sides to allow seasonal movement.
- If the gap is too tight, use a circular saw or oscillating tool to trim the edge of the laminate back from the wall.
- Once expansion gaps are correct, lift the affected planks (they pop up by lifting at an angle, start from the end of a row) and re-engage them properly.
- Reinstall the baseboards.
For a single damaged plank in the middle of a floor, there’s a trick: cut the bad plank free along its seams with an oscillating multi-tool, slow, careful work, then trim the locking tongue off one edge of a replacement plank so it drops in vertically instead of needing to be slid horizontally. Glue the seams with PVA wood glue, weight them with a stack of books overnight. Seams tight, floor flat, no one can tell where the patch is.
Special Case: Laminate vs. LVP (Luxury Vinyl Plank)
Most of this guide applies equally to laminate and LVP, but LVP is more forgiving of shifting because the planks are slightly flexible. For LVP gaps, the tap-back method works even better.
For real hardwood that looks similar to laminate, this guide doesn’t apply, hardwood nailed to a subfloor doesn’t shift the same way.
Common Mistakes to Avoid
Tapping with a regular hammer directly on the plank. Always use a tapping block (a piece of scrap laminate or wood between the hammer and the plank) or a pull bar, never the hammer directly on the floor. You’ll damage the plank’s edge.
Filling a gap that needs the planks tapped together. Filler in a separated joint will pop out as the plank continues to shift. Address the cause, not the symptom.
Ignoring the expansion gap. If your laminate floor has no expansion gap at the walls, it will buckle as it expands. The gap is built into the design.
Working with too-soft filler. Some fillers shrink as they cure and the gap reappears. Use a filler designed for laminate seams, not generic wood filler.
Pulling on the visible side of a plank. Always pull from the end, not the long side. Pulling from the side will rip the click-lock joint.
Frequently Asked Questions
Should I run a humidifier in winter to prevent seasonal gaps? Yes, especially in homes with low winter humidity. Keep relative humidity at 35-55% year-round and laminate moves less.
My floor is gapping near a heating vent. Why? Heat from the vent dries the laminate locally, causing it to contract. Either redirect the airflow with a vent deflector or accept the gap as seasonal.
Can I just replace one plank in the middle of the room? For floating floors, yes, using the multi-tool method above. It’s careful work but it’s possible. Cutting out a single plank without removing every plank between it and the wall is tricky but doable.
The gap is too big to tap shut. That means the floor has expanded too much somewhere else (the wall sides need more expansion gap), OR a plank’s click-lock is broken. Address the cause, or that plank may need replacement.
Will fillers turn yellow over time? Quality laminate seam fillers don’t. Generic wood fillers can yellow. Buy the right product.
My floor started gapping after a water leak. Dry it out and reinstall, or replace? Replace it. Laminate’s inner core is HDF (high-density fiberboard), and HDF swells when wet. It doesn’t return to its original dimensions after drying. Swollen edges mean the click-lock joints no longer seat cleanly, so gapping and minor buckling become permanent. If you catch the water within 12-24 hours, pull up the affected planks, air-dry them flat on a hard surface, and check each one. If the edges are bowed or the planks rock on a flat floor, they’re done regardless of how dry they feel. LVP (luxury vinyl plank) handles water exposure much better because the core is 100% vinyl, not wood-fiber based. If you’re replacing water-damaged laminate in an area prone to moisture, LVP is the upgrade worth making at the same time.
Three causes, three fixes: a shifted plank gets tapped back, a stable cosmetic gap gets seam filler, and a real installation issue gets a reinstall. Most laminate gaps are the first one, which is why a pull bar pays for itself the first time you use it.