Gaps in laminate flooring can disrupt appearance as well as comfort and durability. These gaps often arise from installation flaws, environmental changes, or moisture issues. Understanding why gaps form, how to address them, and how to prevent recurrence helps homeowners maintain a smooth, long-lasting surface. This guide explains common causes, practical DIY fixes, and preventive strategies for gaps in laminate flooring.
Causes Of Gaps In Laminate Flooring
Laminate planks lock into a floating system that relies on proper acclimation and a stable environment. When planks are installed without allowing for room conditions or without adequate expansion space, gaps can appear soon after installation or during seasonal changes.
Environmental fluctuations drive expansion and contraction. Low humidity in winter can cause small gaps to open between boards, while higher humidity in summer can make planks swell and press against each other.
Moisture and subfloor issues are a common culprit. A flexing or uneven subfloor, water leaks, or moisture migrating from above or below can separate boards and weaken locking mechanisms.
Wear from foot traffic, heavy furniture, or impact can loosen joints over time, creating or widening gaps between planks.
Common Gap Scenarios And How They Differ
Not all gaps mean the same problem. Gaps along the room perimeter often indicate an expansion gap that must be preserved, while gaps between boards usually point to locking failure, improper installation, or moisture effects.
Expansion Gaps Versus Board Gaps
Expansion gaps are intentional spaces along the room’s edge or where the floor meets walls. They accommodate seasonal changes and should be hidden by baseboards or molding.
Board gaps are spaces between planks in the field. They may signal planks that are not fully clicked, moisture damage, or a warped subfloor.
Repairing Gaps In Laminate Flooring
- Diagnose the cause. Check humidity, inspect the area for moisture sources, and examine the locking joints to determine whether gaps are decorative or structural.
- Tighten small gaps between boards. If planks are mostly locked but a narrow gap exists, use a tapping block and mallet to gently close the seam. Work from the center toward the gap to avoid damaging edges.
- Re-seat loose boards. For boards that have pulled apart, lift the board slightly, align the tongue-and-groove joints, and re-click using a pull bar and tapping block. Avoid twisting planks; apply even pressure along the seam.
- Address moisture-driven gaps. If gaps appear after water exposure, identify and fix the source (leaks, spills, or high humidity). Dry the area thoroughly, lower humidity with a dehumidifier, and consider replacing any swollen or damaged planks.
- Gaps near walls. Expansion gaps along walls are normal. Do not glue lock seams to close them. If a visible gap distracts from the floor, install or adjust baseboards or quarter-round molding to conceal the gap while preserving the expansion space.
- Replace severely damaged planks. If joints won’t click or planks are chipped, warped, or swollen beyond repair, removing and replacing affected boards is usually the best option. Follow manufacturer instructions for removal and installation.
Preventing Gaps In The Future
- Acclimate properly. Allow laminate to acclimate in the installation space for 48–72 hours before installation, or as recommended by the manufacturer, to match room conditions.
- Control the environment. Maintain consistent humidity (roughly 40–60% relative humidity) and temperature (about 60–80°F) to minimize expansion and contraction.
- Prepare a proper subfloor and underlayment. Ensure a flat, clean, dry subfloor and use the manufacturer-approved underlayment to support locking and moisture control.
- Follow expansion-gap guidelines. Leave the required perimeter expansion gap (often 3/8 to 1/2 inch) and conceal it with baseboards or molding. Do not seal these gaps with glue or filler.
- Protect the floor from moisture. Clean spills promptly, use mats in entryways, and avoid exposing laminate to standing water. Address plumbing leaks and high moisture sources quickly.
- Prevent movement during furniture setup. Use furniture coasters and felt pads to reduce concentrated pressure that can loosen joints. Lift furniture rather than drag it across the surface.
Environmental And Installation Guidelines
| Guideline | Recommended Range | Notes |
|---|---|---|
| Relative Humidity | 40–60% | Extreme humidity causes swelling or shrinking; maintain stable levels with a humidifier or dehumidifier as needed. |
| Temperature | 60–80°F | Rapid temperature changes can accelerate expansion or contraction of planks. |
| Expansion Gap | 3/8–1/2 inch | Preserve along walls; baseboards conceal the gap. |
| Acclimation Time | 48–72 hours | Follow manufacturer recommendations for your product. |
Tools And Materials For Gaps Repair
- Laminate installation kit: tapping block, pull bar, hammer
- Utility knife and spare blades
- Moisture meter to check subfloor moisture
- Dehumidifier and hygrometer to monitor humidity
- Baseboard or quarter-round molding for gap concealment
- Color-matched sealant or flexible caulk (for perimeter gaps only when recommended by the manufacturer)
- Replacement planks of the same product line
When To Call A Professional
If gaps persist after DIY efforts, or if moisture sources are suspected (leaks, hidden water damage, or persistent rising humidity), a flooring professional should evaluate the installation. Structural subfloor issues or widespread plank damage may require a full replacement or subfloor repair, which professionals are better equipped to assess and execute safely.