How to Fix Gaps in Laminate Flooring Before They Get Worse

Gaps in laminate flooring don’t just affect appearance, they can compromise the durability of your entire floor. If you’re searching for how to fix gaps in laminate flooring before they spread, you’re taking the right first step. Over time, minor plank separation can collect debris, trap moisture, and place stress on surrounding boards. Fortunately, most gap issues are manageable with simple tools and a little know-how. In this guide, you’ll learn what causes laminate planks to separate, how to prevent further movement, and the best DIY methods to close gaps for good.

Why Do Gaps Form in Laminate Flooring?

Understanding why gaps appear is the first step toward fixing them properly. Laminate flooring is a floating floor system. The planks are not nailed or glued to the subfloor. Instead, they lock together and “float” above the surface. This design allows the floor to expand and contract naturally with changes in temperature and humidity.

When conditions change or installation mistakes are made, gaps can develop between planks. Here are the most common causes.

Temperature and Humidity Fluctuations

Laminate flooring expands in warm humid conditions and contracts when it gets cold and dry. When the floor contracts significantly, it can pull planks apart and create visible gaps. This is especially common in homes with forced-air heating during winter or in regions with dramatic seasonal changes.

Incorrect Expansion Gaps During Installation

Every laminate floor needs a small gap around the perimeter of the room. This is called the expansion gap. It gives the floor room to breathe. If this gap is too small or if baseboards are installed too tightly against the floor, the planks have nowhere to expand. That pressure builds inward and pushes planks apart in the middle of the room.

Subfloor Issues

An uneven subfloor creates pressure points. Over time, planks over low spots begin to shift and separate. A poorly prepared subfloor is one of the most overlooked causes of gaps.

Wear and Foot Traffic

In high-traffic areas, repeated pressure and movement can loosen the click-lock joints between planks. Over time, this causes them to drift apart slightly, creating small but noticeable gaps.

Moisture Damage

Water getting under your floor causes the core material to swell and warp. Once the moisture dries, the planks shrink back but do not always return to their original position. This can leave gaps or trigger floor buckling in extreme cases.

The Difference Between Normal and Problematic Gaps

Not every gap requires immediate repair. Laminate flooring naturally develops very small, almost invisible separations during dry seasons. These typically close up again when humidity levels rise. These are considered normal seasonal movements.

However, if the gaps are wide enough to trap dirt, visible from a standing position, or growing larger over time, that is a sign of a structural or environmental problem that needs to be addressed. You should also act quickly if you notice floor buckling or raised plank edges around the gap, as these signs indicate moisture or installation issues that will worsen without intervention.

Tools and Materials You Will Need

Before starting any laminate floor repair for gaps, gather the right tools. Having everything on hand makes the process faster and cleaner.

• Floor gap fixer tool (also called a gap pull tool or tapping block)
• Rubber mallet
• Flooring pull bar
• Laminate floor gap filler (color-matched to your floor)
• Putty knife or plastic scraper
• Painter’s tape
• Clean cloth
• Humidity meter (optional but helpful)

For small cosmetic gaps that cannot be physically closed, a laminate floor gap filler in a matching color is your best option. For gaps caused by plank separation, the floor gap fixer tool combined with a rubber mallet will bring the planks back together.

How to Fix Small Gaps Between Laminate Planks

Small gaps between planks are usually caused by seasonal contraction. If the gap is less than about 2mm and the planks are not damaged, you can close them mechanically.

Step 1: Identify the Direction of the Gap

Walk the floor and note where the gaps appear. Are they scattered or concentrated in one area? Gaps near the center of a room often indicate that the expansion gap around the perimeter is blocked.

Step 2: Check the Expansion Gap

Remove the baseboard or quarter-round molding along the nearest wall. Look at the perimeter gap around the floor’s edge. If the floor has expanded into that space and is pressing against the wall, this is preventing the planks from sitting flat. Trimming the perimeter slightly can relieve pressure and allow the planks to settle back together.

Step 3: Use the Gap Fixer Tool

If the perimeter gap is fine, use a floor gap fixer tool. These tools use adhesive pads that attach to the face of a plank. You then tap the tool gently with a rubber mallet to slide the plank toward its neighbor. Work plank by plank along the affected area. This process brings separating planks back into contact with each other.

Step 4: Reinstall Molding

Once the planks are snug, reattach the baseboard or quarter-round molding. Do not push it tightly against the floor. Leave just a small gap so the floor still has room to move with seasonal changes.

How to Fill Gaps That Cannot Be Closed Mechanically

Some gaps are caused by minor plank damage, slight warping, or age-related wear. In these cases, the planks cannot be brought fully together. A laminate floor gap filler is the right solution here.

Step 1: Clean the Gap

Use a vacuum or soft brush to remove all dust, debris, and dirt from inside the gap. The filler will not bond properly to a dirty surface.

Step 2: Select the Right Color

Choose a laminate floor gap filler that closely matches your floor’s color. Many repair kits include multiple color options that can be blended together. Test the color on a small inconspicuous area first.

Step 3: Apply the Filler

Using a putty knife or the applicator included with your repair kit, press the filler into the gap. Overfill slightly, as the material shrinks a little as it dries.

Step 4: Smooth and Wipe

Before the filler sets, use a plastic scraper to level it flush with the surface of the floor. Wipe away any excess with a clean damp cloth. Allow the filler to dry fully according to the manufacturer’s instructions.

Step 5: Buff the Area

Once dry, lightly buff the repaired area with a soft cloth to blend the filled gap with the surrounding floor. The result should be nearly invisible.

For more repair techniques on damaged planks and surface issues, see How Can Damaged Laminate Flooring Be Repaired.

Dealing With Floor Buckling Around Gaps

Floor buckling is a more serious condition. It happens when planks push upward due to too much expansion with nowhere to go. Buckling often appears as a ridge or hump running across the floor and is frequently accompanied by visible gaps on either side.

If you see floor buckling, the most common fix involves creating more room for the floor to expand.

Start by removing the baseboard and checking whether the floor is pushing against the wall. Carefully trim the edge of the affected planks using a utility knife or oscillating tool to add more space at the perimeter. Once the pressure is relieved, the buckled area may settle on its own within a few days, especially in warm or humid conditions.

If the buckling is severe or involves multiple planks that have separated, cracked, or warped, those planks will need to be replaced. For step-by-step guidance on replacing individual planks, read How to Repair Scratches on Laminate Flooring.

Preventing Gaps From Forming Again

Once you complete your laminate floor repair, taking a few preventive steps will help keep the floor tight and gap-free long term.

Control Indoor Humidity

Keep indoor humidity levels between 35% and 55% year-round. Use a humidifier during dry winter months and a dehumidifier in summer if your area is particularly humid. Stable moisture levels are the single most effective way to prevent seasonal gaps from forming.

Never Wet Mop Laminate

Excess water on laminate floors seeps into the seams and can weaken the click-lock joints over time. Always use a damp mop and dry the surface immediately. Learn safe cleaning methods in How to Properly Clean and Maintain Your Laminate Flooring.

Protect Against Moisture at the Source

Place mats at entry doors to trap moisture from shoes. Use waterproof trays under pet water bowls and appliances. Address any plumbing leaks immediately. 

Acclimate New Flooring Before Installation

If you are replacing planks or installing a new floor, always allow the material to acclimate to your home’s conditions for at least 48 hours before installation. Skipping this step is one of the leading causes of post-installation gaps and buckling.

Check Expansion Gaps When Installing

Always maintain the recommended perimeter expansion gap during installation, typically around 10mm to 12mm from the wall. Never block this space with furniture legs or heavy objects placed directly against the baseboard.

When to Call a Professional

Most gaps in laminate flooring are manageable as a DIY project. However, if you notice widespread floor buckling across multiple rooms, moisture damage reaching the subfloor, or planks that continue to separate even after repair, it is time to bring in a professional. A flooring specialist can assess whether the subfloor needs leveling, whether moisture barriers are missing, or whether the entire floor needs replacing.

Knowing when to move from DIY to professional laminate floor repair can save you significant money and prevent structural damage from spreading.

Final Thoughts

Gaps in laminate flooring are a common issue, but they do not have to become a major problem. Acting early with the right tools and the right laminate floor gap filler can save your floor from more serious damage like buckling, warping, or deterioration of the click-lock system. Whether the fix involves mechanically closing plank separations, applying filler, or addressing perimeter expansion issues, the key is to act before small gaps become large structural problems.

For high-quality laminate flooring, repair materials, and expert advice, visit Flooring Outlet & More. Our team is ready to help you find the right products and solutions to keep your floors in excellent condition for years to come. You can also explore our full range of laminate flooring options and installation materials to get everything you need in one place.

Frequently Asked Questions

Q: What is the best laminate floor gap filler to use for small gaps?

A: The best laminate floor gap filler depends on the gap size and color match. For small gaps, a color-matched wood putty or flexible floor filler works well. Always test the color in a hidden area first. Many repair kits include multiple shades that can be blended for a precise match to your floor tone.

Q: Can temperature changes really cause gaps in laminate flooring?

A: Yes, temperature and humidity changes are one of the most common reasons gaps appear. Laminate contracts in dry cold conditions and expands in warm humid ones. Keeping indoor humidity between 35% and 55% year-round dramatically reduces seasonal movement and helps prevent gaps from forming or widening between planks over time.

Q: How do I know if my laminate gap is a normal seasonal gap or a serious problem?

A: Seasonal gaps are very small, usually less than 1mm, and often close back up when humidity rises. If gaps are wide enough to collect dirt, visible from a standing position, growing over time, or accompanied by floor buckling or raised edges, they indicate a more serious installation or moisture problem that needs to be addressed promptly.

Q: Is floor buckling always caused by moisture?

A: Floor buckling is most often caused by moisture but can also result from an insufficient expansion gap during installation. When a floating floor has nowhere to expand, internal pressure forces planks upward. Checking and correcting the perimeter expansion gap is usually the first step before assuming moisture is the cause of laminate floor buckling.

Q: Can I fix gaps in laminate flooring without removing the baseboards?

A: For small gaps, a laminate floor gap filler can be applied without touching the baseboards. However, if the cause is a blocked expansion gap or widespread plank separation, you will need to remove the baseboards temporarily to relieve pressure and use a gap fixer tool to bring the planks back together properly before reinstalling the trim.