Laminate Floor Buckling or Lifting

Common Symptoms

• Planks forming a ridge or hump in the middle of the room
• Edges of planks lifting away from the subfloor
• Visible gaps forming between planks
• Buckling near walls, doorways, or under cabinets
• Floor feels spongy or soft underfoot near the buckling area

Most Likely Causes

1. 1

   Missing or Blocked Expansion Gap (Most Common)

   Laminate is a floating floor — it's not fastened to the subfloor and must be free to expand and contract. Building code and manufacturer specs require a minimum 1/4" gap around all walls and fixed objects. If baseboards were installed without spacers, or if the floor was pushed tight to a wall, there's nowhere for the planks to expand and they buckle upward.

2. 2

   Moisture Under the Floor

   Laminate swells permanently when wet. A plumbing leak, high subfloor moisture (especially on concrete slabs), or a flooding event can cause boards to swell and buckle. Moisture-damaged planks cannot be flattened — they must be replaced.

3. 3

   Transition Strip Issues at Doorways

   Transition strips at doorways must bridge the gap between rooms without pinching the floor. A T-molding transition that's screwed or glued directly to the laminate (instead of to the subfloor) can prevent expansion and cause buckling near the doorway.

4. 4

   Glued vs. Floating Floor Confusion

   Some older laminate installations were fully glued to the subfloor. Glued floors react differently to moisture and cannot float — attempting to leave expansion gaps in a glued floor creates different problems. Knowing which type you have determines the repair approach.

Quick DIY Checks

1. 1**⚠️ Stop walking on the buckled area immediately.** Foot traffic on a buckled section snaps click-lock joints, turning a simple gap-gap repair into a full plank replacement.
2. 2**Inspect the expansion gap:** Remove the baseboards or quarter-round trim along the walls nearest the buckle. Use a putty knife to check the gap between the last plank and the wall. If it's zero — or you find a plank wedged tight against the wall — that's your cause. A 1/4" minimum gap is required on all four sides of the room and around any fixed object (islands, columns, door frames).
3. 3**Recut the expansion gap if blocked:** If the planks are tight to the wall, use a oscillating multi-tool or a pull saw to trim the end of the last plank row, creating the required 1/4" gap. Work your way around the perimeter. Reinstall the trim — trim covers the gap visually and should never touch the laminate surface.

Repair vs Replace

Recommended Tools & Parts

• Laminate Floor Pull Bar and Tapping Block Set

  Essential for assembling and disassembling click-lock laminate rows without breaking the tongue-and-groove joints. Fits all standard click-lock profiles.

  $15–$30

  Buy on Amazon →

• Digital Moisture Meter

  Pin-type meter for testing subfloor moisture levels before installing or repairing laminate. Detects hidden moisture that causes buckling and swelling.

  $20–$45

  Buy on Amazon →

• Laminate Flooring Expansion Spacers

  Plastic spacers that clip to wall edges during installation to maintain a consistent 1/4" expansion gap around the perimeter of the room.

  $8–$15

  Buy on Amazon →

Links are Amazon affiliate links (tag: fixitfastai-20). Prices are estimates.

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