Laminate flooring is a popular choice for durability and affordability, but moisture intrusion can cause swelling or warping. Homeowners often wonder if swollen planks will return to normal once the moisture is removed. The answer depends on the extent of water exposure, the laminate construction, and how quickly moisture is addressed. This guide explains why laminate floor swelling happens, whether it typically reverses, practical steps to dry and repair, and proven prevention tips to minimize future issues across a typical American home.
What Causes Laminate Floor Swelling
Laminate flooring uses a high-density fiberboard core and a protective wear layer. When moisture penetrates through gaps, seams, spills, or subfloor, the core absorbs water and swells. Common sources include spilled liquids that aren’t cleaned promptly, high indoor humidity, or leaks from appliances and plumbing. Improper installation, such as insufficient expansion gaps or moisture in the subfloor during installation, can trap moisture and lead to swelling at edges and around fixed objects like toilets or cabinets. In basements or crawl spaces, poor ventilation can worsen humidity and swelling risk.
Different types of moisture behave differently. Surface moisture on top of the plank may dry quickly, potentially reducing minor swelling. But if water reaches the core, the swelling can become permanent or cause delamination, making planks unstable. Regular cleaning methods that use excess water can accelerate damage, and steam mops should be avoided on laminate floors unless the manufacturer permits it.
Will Swelling Go Down On Its Own?
Temporary Swelling
In many cases, swelling that results from recent spills or high humidity can subside as the area dries. If moisture is confined to the surface and the underlayment and subfloor remain dry, the planks may return to nearly their original dimensions after proper drying. This is more likely for superficial edge swelling than for planks with visible core moisture damage.
Permanent Or Semi-Permanent Swelling
When the center of a laminate plank or the edges show lasting distortion, a sign that the core has absorbed water, swelling is generally not fully reversible. The core’s edema can prevent full reversion, and the planks may stay warped or buckle after drying. Delamination, where the wear layer separates from the core, is another irreversible outcome if moisture intrusion is severe. In these cases, replacement is typically the best solution.
Drying, Stabilizing, And Preventing Further Damage
Act quickly after noticing swelling. The first step is to identify and stop the moisture source to prevent additional damage. Drying should aim to reduce humidity and remove standing water from both the surface and underneath the floor when accessible. Use dehumidifiers set to a comfortable humidity level, typically 30-50% for living spaces, and increase air movement with fans. If the swelling is localized, removing baseboards and lifting affected planks may be necessary to allow air to reach the subfloor and underlayment.
Practical steps include:
- Wipe up spills immediately with a dry cloth or absorbent towel; avoid soaking the floor with water.
- Ventilate the area and run a dehumidifier until the moisture source is eliminated and the room stabilizes.
- Offer targeted air flow with box fans directed at swollen boards to hasten drying, and keep doors open to improve circulation.
- Check for hidden leaks behind toilets, sinks, or appliances; address any plumbing issues promptly to prevent recurring moisture.
- Inspect the underlayment and subfloor to ensure there is no standing moisture; if moisture persists, professional assessment is advised.
Repairing Or Replacing Damaged Planks
Swollen planks that have shown irreversible distortion or delamination typically require replacement. With floating laminate floors, this involves removing baseboards and the affected planks, then installing new ones. In many cases, you’ll need to cut out the damaged boards and replace them with matching planks, ensuring the expansion gaps remain intact.
Repair steps include:
- Carefully lift the swollen plank using a putty knife and a tapping block to avoid damaging adjacent boards.
- Measure the defect and cut a replacement plank to fit precisely, maintaining the same thickness and locking system.
- Install replacement planks, re-seal any seams, and reattach the baseboards. Recheck the area for any residual moisture before finalizing.
Note that if the subfloor remains moist, replacement alone may not resolve the problem; drying the subfloor is essential to prevent future swelling of new planks. In some cases, hiring a professional to extract moisture and evaluate the subfloor is prudent.
Prevention To Minimize Future Swelling
Prevention is the best strategy to protect laminate floors from swelling. Proper installation with adequate expansion gaps and a moisture barrier beneath the laminate helps. Maintain comfortable indoor humidity, typically between 30% and 50%, depending on climate and season. Immediate cleanup of spills and prompt repair of leaks reduce the risk of swelling.
- Choose laminate products rated for moisture resistance and use boards with built-in water resistance if your home has higher humidity or near entryways and kitchens.
- Install proper expansion gaps around the perimeter and around fixed objects as recommended by the manufacturer.
- Use area rugs or runners in moisture-prone zones like kitchens, entryways, and bathrooms (if compatible with your laminate’s installation).
- Use a vapor barrier when installing in basements or over concrete slabs; maintain subfloor dryness during installation.
- Regularly inspect for leaks under sinks and appliances; address issues before they reach the laminate.
Professional Help And When It Is Needed
Some swelling issues are straightforward and can be addressed by homeowners, while others require professional assessment. If swelling is widespread, if there is visible mold growth, or if you suspect a hidden leak behind walls, consult a flooring contractor or plumber. A pro can test moisture levels with a Hygrometer and infrared camera, determine the extent of damage, and propose a replacement plan that preserves the floor’s appearance and structural integrity.