SPC flooring is valued for its rigid core and dimensional stability, but gaps, buckling, raised edges and separated joints can still occur. These problems are usually connected to heat, restricted floor movement, unsuitable site conditions, click-lock damage or inconsistent product quality.

For importers, distributors, contractors and commercial project buyers, replacing damaged planks without identifying the underlying cause may provide only a temporary solution. The complete flooring system—including the product, subfloor, installation layout and indoor conditions—should be inspected first.

This guide explains nine common causes of SPC flooring expansion, shrinkage and buckling, along with the practical checks required before installation or corrective work.

Quick Answer: Why Does SPC Flooring Expand, Shrink or Buckle?

SPC flooring normally develops gaps or buckling when the floating floor cannot move correctly, receives excessive localized heat or loses support beneath the click-lock joints.

The visible symptom alone does not prove whether the cause is product quality, installation or the site environment. Record the affected area and inspect the complete flooring system before deciding on a repair.

1. Direct Sunlight and High Floor-Surface Temperature

SPC flooring installed beside large windows, glass doors or shopfront glazing can receive concentrated solar heat. The temperature of the sunlit floor may become considerably higher than the surrounding room or shaded areas.

This uneven heating can create movement within the flooring system. If the planks are pressed against walls, thresholds, columns or fixed fixtures, the floor may lift, buckle or place additional stress on the click-lock joints.

Commercial projects with large glazed areas should evaluate:

• The direction and duration of direct sunlight

• The size and specification of the glazing

• Expected floor-surface temperature changes

• Window blinds, curtains or solar-control film

• Perimeter clearance and transition planning

• The flooring manufacturer’s installation instructions

Checking the room temperature alone may not identify localized heat. The floor-surface temperature near windows should also be examined when buckling occurs in a specific area.

2. Insufficient SPC Flooring Expansion Gap

A floating SPC floor needs sufficient clearance around walls and other fixed building elements. The required expansion gap depends on the product, room dimensions, installation layout and manufacturer’s instructions.

Clearance should be checked around:

• Walls and skirting

• Door frames and thresholds

• Columns and floor penetrations

• Built-in cabinets and counters

• Fixed partitions

• Large connected flooring areas

A common problem occurs when clearance is left during installation but later blocked by tight skirting, sealant, screws or fixed fittings. The finished floor must remain able to move according to its installation design.

3. Floating SPC Flooring Trapped by Cabinets or Fixed Fixtures

Floating SPC flooring should not be unintentionally locked in place by permanent cabinets, counters, partitions or other fixed structures. When a large section of flooring is trapped, normal movement may become concentrated in another area and cause lifting or joint separation.

The flooring layout should therefore be coordinated with the cabinet and fit-out plan before installation starts. Contractors should determine where the floating floor will terminate and which fixtures must be installed independently.

Heavy movable furniture is different from a permanently fixed structure. However, concentrated loads and unsuitable furniture feet can still affect the surface or joints and should be considered during project planning.

4. Large Areas Without Suitable Transition Planning

Hotels, offices, schools, retail stores and apartment projects may contain long corridors, connected rooms or large open spaces. Installing one continuous floating floor through a complicated layout may increase stress within the system.

Transition requirements should be confirmed before material cutting begins. Correcting an unsuitable layout after installation is usually more difficult and expensive.

5. Uneven or Unsuitable Subfloor

An uneven subfloor does not directly cause every expansion problem, but unsupported areas can move under foot traffic and place repeated stress on the locking joints. This may lead to clicking noise, separated plank ends, raised edges or broken click-lock profiles.

Subfloor inspection should cover:

• Flatness across the complete installation area

• Local high and low points

• Surface strength and cleanliness

• Cracks and unstable repairs

• Moisture conditions

• Debris remaining beneath the flooring

A thicker SPC plank or softer underlayment should not be used as a substitute for proper subfloor preparation.

See our SPC flooring subfloor requirements guide for a more detailed inspection checklist.

6. Moisture and Unsuitable Site Conditions

The SPC core is water-resistant, but this does not mean the complete flooring system can be installed over an actively wet or unprepared surface. Moisture beneath the floor may affect the subfloor, attached backing, separate underlayment or surrounding building materials.

Active leaks, wet screed and unsuitable substrate conditions should be resolved before installation. Moisture testing and acceptance requirements should follow the project specification, local construction practices and flooring manufacturer’s instructions.

Water-resistant flooring and correct site preparation are separate issues. Buyers should avoid treating SPC flooring as a solution for unresolved moisture problems.

7. Incorrect Storage and Site Conditioning

Flooring stored in an extremely hot, cold or exposed location may enter the installation area under conditions that differ significantly from the room environment. Cartons may also become distorted when stored upright or without even support.

Before installation:

• Keep cartons flat and properly supported

• Protect flooring from weather and direct sunlight

• Avoid extreme warehouse and site temperatures

• Move the flooring into suitable site conditions

• Follow the supplier’s storage and conditioning instructions

• Inspect cartons and sample planks before opening the entire order

For export orders, storage should be controlled through factory warehousing, container loading, ocean shipment and destination storage.

8. Damaged or Incorrectly Installed Click-Lock Joints

A visible gap does not always mean the SPC material has shrunk. The locking profile may be damaged, incompletely engaged or repeatedly stressed by movement over an uneven subfloor.

Common click-lock problems include:

• Joining planks at an incorrect angle

• Using excessive force during installation

• Installing planks with damaged locking profiles

• Leaving dust or debris inside the joint

• Failing to engage the complete plank length

• Continuing installation after a joint problem appears

The first completed rows should be inspected carefully. An early alignment error can affect subsequent rows and become harder to correct later.

For additional checks, read our SPC flooring installation mistakes guide.

9. Raw Materials and Production Consistency

Dimensional stability also depends on the SPC core formulation, raw-material consistency, extrusion control, cooling process and dimensional tolerances. Flooring from different factories—or different quality levels from the same market—should not be assumed to perform identically.

Before approving a bulk order, buyers should confirm:

The product supplied in bulk should match the approved sample, quotation and purchase specification.

Buyers comparing core formulations can also read our virgin vs recycled SPC flooring quality guide.

How Commercial Buyers Can Reduce SPC Flooring Claims

Preventing complaints requires coordination between the flooring supplier, buyer and installer. Product specifications alone cannot correct unsuitable storage, subfloor or installation conditions.

What to Inspect After Gaps or Buckling Appear

Record the site conditions before removing large sections of flooring. Useful evidence includes:

• Location and size of the affected area

• Photos of the floor, walls, windows and doorways

• Room temperature and floor-surface temperature

• Direct sunlight exposure during the day

• Perimeter clearance after removing the trim

• Subfloor flatness and moisture condition

• Location of cabinets, partitions and fixed fixtures

• Batch numbers, carton labels and remaining samples

• Condition of the click-lock profiles

• Installation date and the date the problem appeared

This information helps the supplier, installer and project team distinguish between restricted movement, joint damage, product inconsistency and site-related conditions.

Frequently Asked Questions

Does SPC flooring expand in hot weather?

SPC flooring can experience dimensional movement when exposed to heat. The risk increases when strong sunlight creates localized high floor temperatures and the floor cannot move because its perimeter clearance is restricted.

Why is SPC flooring buckling near a window?

Localized solar heat and insufficient movement space are common causes to investigate. Check the surface temperature, perimeter clearance, window shading and whether fixed fixtures are trapping the floor.

Why are gaps appearing between SPC planks?

Possible causes include damaged or incompletely engaged locking joints, temperature changes, an uneven subfloor, installation movement or inconsistent plank dimensions. Inspect the joints and site conditions before assuming that the core has shrunk.

How much expansion gap does SPC flooring need?

The required gap depends on the flooring product, room size, layout and site conditions. Follow the current installation instructions supplied for the specific product instead of applying one measurement to every project.

Can SPC flooring be installed under kitchen cabinets?

A floating SPC floor should not be unintentionally trapped beneath permanent cabinets or fixed structures. Coordinate the flooring layout with the cabinet and fit-out plan before installation.

Can an uneven subfloor cause SPC joints to separate?

Yes. Unsupported sections can move under traffic and place stress on the click-lock joints. The subfloor should be inspected and corrected before installation.

Does thicker SPC flooring expand less?

Not necessarily. Thickness is only one part of the flooring structure. Core formulation, temperature, dimensional accuracy, locking quality and installation conditions also affect performance.

Can additional underlayment prevent SPC flooring gaps?

Not automatically. An unsuitable or excessively soft underlayment may increase movement at the locking joints. Use only an underlayment approved for the flooring system.

See our SPC flooring underlayment guide for more information.

Who is responsible when SPC flooring buckles?

Responsibility cannot be determined from the visible symptom alone. Product quality, storage, temperature, subfloor preparation, layout and installation methods should all be investigated using documented evidence.

Should damaged SPC flooring be replaced immediately?

Identify and correct the underlying cause first. Replacing individual planks without resolving heat exposure, restricted clearance, subfloor movement or locking damage may allow the problem to return.

Request SPC Flooring Specifications and a Factory Quote

For wholesale or commercial projects, send Floren Floor your required thickness, wear layer, backing, plank size, order quantity, application and destination country. We can help confirm the product structure, packing details and suitable sample options before quotation.

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A clear specification and documented installation plan can reduce misunderstandings between the supplier, buyer and contractor—and make expansion, buckling and joint complaints easier to prevent.