Why Is My Laminate Floor Swelling and Buckling? Causes and Fixes for WNC Homes

Laminate floor swelling and buckling happen when moisture gets into the high-density fiberboard (HDF) core of the plank. The HDF core is made from compressed wood fibers, and like all wood-based materials, it absorbs water. When it does, it expands. Because laminate planks are laid tightly together with click-lock seams, the expansion creates pressure between planks. When the pressure builds enough, planks push upward at the joints and the floor buckles.

Laminate floor swelling and buckling are different from the normal seasonal expansion and contraction that all flooring experiences. Normal expansion causes planks to sit slightly tighter against each other. Moisture-driven laminate floor swelling causes visible distortion, soft spots underfoot, and raised seams that can trip household members.

The Top Causes of Laminate Floor Swelling in WNC Homes

1. Crawl Space Moisture Migration

This is the most common cause of laminate floor swelling and buckling in Buncombe and Henderson County. Many WNC homes, especially those built before the 1990s, have crawl spaces beneath the main floor. When the crawl space lacks an adequate vapor barrier, ground moisture evaporates and travels upward through the subfloor. That moisture accumulates under the laminate and eventually works its way into the planks through the seams and edges.

Laminate floor swelling and buckling from crawl space moisture is often most visible in the lowest spots on the floor, near exterior walls, or in areas over the coldest part of the crawl space. If you notice the problem worsening through the summer months when ground moisture is highest, the crawl space is almost certainly involved. Our laminate installation page explains how we address subfloor moisture before every installation.

2. Inadequate Expansion Gaps

Every laminate floor needs a gap around its perimeter, typically a quarter to three-eighths of an inch, to allow the floor to expand seasonally without buckling. If that gap was too small during installation, even normal seasonal expansion can trigger laminate floor swelling and buckling against the walls, which pushes the planks inward and causes buckling toward the center of the room.

This type of laminate floor swelling and buckling tends to be worse near walls and less severe in the middle of the room. If baseboards are visibly bowing away from walls or if planks near walls are the most distorted, expansion gap issues are a likely factor.

3. Direct Water Exposure

Appliance leaks, flooded basements, slow pipe drips under flooring, and pet accidents are all direct causes of laminate floor swelling and buckling. Unlike crawl space moisture, which is gradual, direct water exposure can cause dramatic laminate floor swelling within 24 to 48 hours. The faster you remove standing water and dry the area, the better the chance that fewer planks are affected.

Laminate floor swelling and buckling from direct water exposure is especially common in kitchens near dishwashers and refrigerators with ice makers, and in laundry areas. If the laminate in your home is in moisture-prone areas, you may want to consider switching to waterproof vinyl plank flooring in those spaces.

4. Seasonal Humidity Swings in WNC

Western NC’s mountain climate brings significant humidity differences between seasons. Summer relative humidity in Asheville and the surrounding valleys can sit in the 70 to 80 percent range for weeks at a time. In homes without climate control that maintains a consistent indoor humidity, the laminate absorbs ambient moisture during humid months and releases it during dry months. Over years of this cycling, planks can develop progressive laminate floor swelling and buckling patterns that don’t fully reverse.

How to Diagnose Laminate Floor Swelling vs. Buckling

Laminate floor swelling and buckling often appear together, but they’re slightly different manifestations of the same moisture problem. Swelling refers to individual planks expanding and becoming raised at their edges. Buckling refers to a larger section of the floor lifting or becoming wavy across multiple planks. Both require the same underlying fix: finding and eliminating the moisture source before addressing the flooring itself.

Symptom	Likely Cause	Urgency
Raised edges at plank seams	Moisture absorption into the HDF core	Moderate, investigate the source
Wavy or humped floor across multiple planks	Crawl space moisture or inadequate expansion gap	High, source must be found
Buckling near walls only	Inadequate expansion gap at the perimeter	Moderate, may need reinstall
Swelling near appliances or bathrooms	Direct water exposure	High, remove water immediately
Soft spots underfoot with visible lifting	Core saturation, delamination likely	High plank replacement needed

Can You Fix Laminate Floor Swelling Without Replacing Planks?

In a small number of cases, very early-stage laminate floor swelling and buckling, where the core hasn’t yet fully saturated, can partially recover with thorough drying. Running dehumidifiers and fans in the affected area for several days, combined with removing the source of moisture, sometimes allows lightly swollen planks to settle back toward normal.

However, once the HDF core has fully absorbed moisture and deformed, the swelling is permanent. The structural fibers of the core have expanded and cannot be compressed back to their original dimension. Those planks need to be replaced.

Replacing laminate planks requires unlocking the click-lock joints back to the affected area, removing the swollen planks, confirming the subfloor is dry, and reinstalling matching planks. This is a job that most homeowners are better off leaving to professionals. Schedule a free in-home assessment, and we’ll evaluate the extent of the damage and the source of the moisture before recommending a repair approach.

Preventing Laminate Floor Swelling in WNC

The most effective prevention strategy for laminate floor swelling and buckling in WNC homes involves three things. First, ensure your crawl space has a full-coverage heavy-duty vapor barrier, ideally 6 mil or thicker, installed across the entire floor area and sealed at the seams. Second, use a whole-home dehumidifier or ensure your HVAC system maintains indoor relative humidity between 35 and 55 percent year-round. Third, clean up any liquid on the floor immediately, never allowing water to sit on the seams.

When installing new laminate, always have the subfloor tested for moisture before installation begins. This is a standard step in Leicester Flooring’s installation process. Visit our laminate flooring overview page to learn more about the products we carry and the brands we recommend for WNC conditions.

Frequently Asked Questions

Why is my laminate floor bubbling or lifting at the edges?

Bubbling or edge lifting is a classic sign of laminate floor swelling. Moisture has reached the HDF core and caused it to expand. The most likely causes in WNC are crawl space moisture migration, inadequate expansion gaps, or direct water exposure from a spill or leak. Find and eliminate the moisture source before attempting any repair.

Will my swollen laminate floor go back to normal on its own?

Possibly, if the swelling and buckling were caught very early, and the core was only lightly affected. In most cases, once visible laminate floor swelling has occurred, the HDF core has already deformed, and the planks need to be replaced. Running a dehumidifier sometimes helps marginally with very early-stage cases, but it’s not a reliable fix.

How long does it take for laminate to swell after water exposure?

Significant laminate floor swelling can be visible within 24 to 48 hours of sustained water exposure. The speed depends on how much water is involved and whether it reaches the seams. A spill wiped up within a few minutes rarely causes lasting damage. Standing water or a slow leak left for days almost always does.

Can I install new laminate over a swollen floor?

No. The swollen laminate must be fully removed before new flooring is installed. Installing over damaged or swollen planks creates an uneven subfloor surface that will cause problems with the new floor. The subfloor must also be fully dried and tested for moisture before any new installation.

Does the manufacturer’s warranty cover laminate floor swelling?

Most manufacturer warranties exclude damage caused by moisture, improper installation, or failure to follow care instructions. Whether swelling qualifies for warranty coverage depends on the cause. Leicester Flooring provides a lifetime installation warranty, which means installation-related issues are covered.

Talk to the Team at Leicester Flooring

Laminate floor swelling and buckling is one of the most common calls we get from homeowners across Western NC. Whether you’re in Asheville, Hendersonville, Weaverville, or anywhere in Buncombe and Henderson County, our team can diagnose the source of the problem and recommend the most cost-effective solution. View our full range of laminate flooring products or contact us to get started.