SPC flooring is widely used in apartments, hotels, offices, retail stores and renovation projects because of its rigid core, waterproof surface and click-lock installation system. However, a stable product can still develop gaps, movement, noise, lifting or damaged joints when the site conditions and installation method are not properly controlled.

Many installation failures are caused by a combination of factors rather than one single mistake. Subfloor flatness, moisture, perimeter clearance, underlayment, room layout, temperature and click-lock assembly should all be checked before the project is accepted.

This guide explains 10 common SPC flooring installation mistakes and provides a practical checklist for contractors, distributors, importers and commercial project buyers.

Quick Answer: What Causes SPC Flooring Installation Problems?

Common SPC flooring installation problems include uneven joints, movement, clicking sounds, broken locking edges, lifting and gaps between planks. These problems may occur when the subfloor is uneven, moisture is not checked, perimeter clearance is incorrect, unsuitable underlayment is used or the click-lock system is forced during installation.

Not every flooring problem is an installation error, and not every problem is a product defect. The correct judgment should consider the product specification, approved sample, production quality, site condition and installation method together.

SPC Flooring Pre-Installation Checklist

Before opening all cartons and starting installation, the contractor should confirm the following conditions:

1. Installing SPC Flooring Over an Uneven Subfloor

An uneven subfloor is one of the most important causes of SPC flooring movement and locking-joint failure. Although SPC has a rigid core, it is not designed to bridge significant low spots, raised areas or loose sections in the substrate.

When a plank is repeatedly pressed over an unsupported area, the locking edges may experience excessive movement. This can lead to:

• Clicking or hollow sounds while walking

• Vertical movement between adjacent planks

• Loose end joints

• Damaged locking edges

• Premature gaps between planks

The contractor should check the entire installation area with suitable measuring tools and correct unacceptable high or low spots before laying the floor. The permitted flatness tolerance should follow the product installation instructions and applicable project requirements.

2. Failing to Check Subfloor Moisture

SPC flooring has a waterproof surface and rigid core, but this does not mean that subfloor moisture can be ignored. Moisture trapped beneath a floating floor may affect the substrate, separate underlayment, adhesives used in nearby areas and the indoor environment.

Concrete, screed and other mineral substrates may retain moisture even when the surface appears dry. The correct moisture test and acceptance limit depend on the substrate, project location and installation system.

Before installation, the project team should confirm:

• The type and condition of the subfloor

• Whether an approved moisture test has been completed

• Whether a vapor-control layer is required

• Whether there is water leakage or rising moisture

• Whether the room has stable ventilation and environmental conditions

Covering an unresolved moisture problem with SPC flooring does not remove the source of the moisture.

3. Using Incorrect Perimeter Clearance

Floating SPC flooring should not normally be installed tightly against walls, columns, door frames, pipes or other fixed structures. Suitable perimeter clearance allows the floor system to respond to normal environmental changes without becoming trapped.

If the clearance is insufficient, pressure may build across the installed area and cause edge lifting, buckling or tight joints. If the clearance is excessive and not properly covered, the edge may become visible after the skirting or trim is installed.

The required clearance is not identical for every product and project. It may depend on:

• Manufacturer instructions

• Room dimensions and layout

• Indoor temperature variation

• Direct sunlight exposure

• Doorways and fixed structures

• Shape of the installation area

Installers should follow the confirmed installation guide instead of applying one clearance value to every SPC flooring project.

4. Ignoring Product Storage and Site Conditions

SPC flooring should be stored and handled according to the supplier’s instructions before installation. Cartons should be protected from rain, extreme heat, direct sunlight and physical damage.

A common mistake is moving flooring directly from an uncontrolled warehouse, container or vehicle into a very different indoor environment and starting installation immediately. Another mistake is storing cartons incorrectly or leaving them in direct sunlight before laying.

Acclimation requirements vary by product and manufacturer. Some SPC products may require conditioning in the installation environment, while other products have different instructions. Contractors should verify the requirement for the supplied product rather than automatically applying one fixed number of hours.

5. Using the Wrong or Double Underlayment

Some SPC flooring is produced with attached IXPE or EVA backing. Other products are designed for use with a separately approved underlayment. Adding an extra soft layer beneath flooring that already has attached backing may create excessive vertical movement.

Too much movement can place additional stress on the click-lock joints and may cause:

• Loose connections

• Joint separation

• Noise while walking

• Uneven foot feeling

• Locking-profile damage

The underlayment should be selected according to the SPC construction, locking system, subfloor and project requirements. Buyers should confirm whether the quotation includes attached backing and whether additional underlayment is permitted.

6. Forcing or Damaging the Click-Lock System

SPC click-lock joints must be connected using the correct direction, angle and installation tools. Forcing the plank into place or striking an unprotected locking edge can damage the profile even if the damage is not immediately visible.

Typical click-lock installation mistakes include:

• Connecting planks at the wrong angle

• Using excessive impact force

• Striking the locking edge directly

• Leaving debris inside the joint

• Continuing installation after a joint is visibly damaged

• Failing to check whether the connection is fully closed

Damaged planks should not be installed in the main floor area. Installers should test several planks before full installation and confirm that the locking method matches the supplied profile.

7. Trapping Floating Flooring Under Fixed Cabinets

A floating SPC floor needs to function as a connected flooring system. Heavy fixed cabinets, kitchen islands, permanent partitions or other structures may restrict movement if they are installed directly through or on top of the floating floor.

This can create pressure around the fixed structure and contribute to lifting, gaps or joint stress in other parts of the room.

The correct treatment depends on the project design and flooring system. Before installation, contractors should identify:

• Fixed cabinets and kitchen islands

• Permanent partitions

• Heavy built-in equipment

• Door frames and tracks

• Floor-mounted fixtures

The installation sequence and clearance around these structures should follow the flooring manufacturer’s instructions.

8. Using a Poor Plank Layout or Joint Pattern

Installation layout affects both appearance and joint stability. Starting without a layout plan may result in very narrow pieces near walls, short end joints, repeated seams or unnecessary material waste.

Before installation, the contractor should calculate the room width, first-row width, final-row width and plank direction. Doorways, corridors and connected rooms should also be considered.

End-joint staggering should follow the product installation instructions. A visually random pattern should still maintain suitable joint separation and avoid weak repetitive layouts.

9. Ignoring Doorways, Large Areas and Complex Room Shapes

A simple rectangular room and a large connected commercial area do not always require the same installation planning. Long corridors, multiple connected rooms, narrow passages and areas exposed to different temperatures may require additional attention.

Depending on the flooring system and project conditions, the installer may need to confirm:

• Transition profiles at doorways

• Movement separation between different areas

• Maximum permitted installation dimensions

• Clearance around columns and fixed structures

• Different sunlight or temperature zones

There is no single transition rule that applies to every SPC product. Large or complex projects should be reviewed against the supplier’s installation guide before work begins.

10. Skipping Final Inspection After Installation

The project should be inspected before skirting, trims and furniture hide important perimeter and joint details. Early inspection makes it easier to correct local issues before the area is handed over.

The final inspection should include:

• Visible gaps or raised joints

• Damaged plank edges

• Movement or noise in high-traffic areas

• Clearance around walls and fixed structures

• Doorway and transition details

• Surface scratches or installation damage

• Skirting and trim installation

• Protection before other construction work continues

The project team should record any problem with clear photos, room location and batch information before deciding whether the cause is related to the product, substrate or installation.

SPC Flooring Problem Diagnosis Table

Important: A visible symptom may have more than one cause. Contractors should avoid replacing individual planks repeatedly without correcting the underlying site or installation condition.

What Importers and Project Buyers Should Confirm

Before approving a bulk SPC flooring order, buyers should request clear information about:

• SPC core and total product thickness

• Wear layer specification

• Attached IXPE or EVA backing

• Plank dimensions and locking profile

• Recommended subfloor conditions

• Storage and site-conditioning requirements

• Expansion-clearance guidance

• Approved installation method

• Batch and carton identification

• Installation and maintenance documents

Physical samples should be checked before bulk production so the buyer can review the surface, color, structure, locking connection and backing.

Learn more about SPC flooring expansion, shrinkage and gap prevention, or explore our SPC flooring options for wholesale and commercial projects.

Frequently Asked Questions

What is the most common SPC flooring installation mistake?

Uneven subfloor preparation and incorrect perimeter clearance are two common sources of problems. However, the actual cause should be confirmed from the gap pattern, joint condition, substrate and site environment.

Does every SPC floor need the same expansion gap?

No. The required clearance may depend on the product, locking system, room dimensions, fixed structures and environmental conditions. Follow the installation instructions provided for the supplied flooring.

Can extra underlayment be installed under SPC flooring with IXPE?

Not automatically. An extra soft layer may create excessive movement and place stress on the locking joints. Confirm whether additional underlayment is approved for the flooring system.

Can SPC flooring be installed over an uneven concrete floor?

The concrete base should first be checked and corrected to meet the required flatness. SPC flooring should not be expected to bridge unacceptable high spots, low areas or loose substrate.

Why does SPC flooring make clicking sounds?

Possible causes include an uneven subfloor, debris beneath the planks, loose click-lock joints, damaged profiles or unsuitable underlayment. The source of movement should be located before repair.

Is a gap between SPC planks always a product defect?

No. Gaps may be related to incomplete locking, joint damage, subfloor movement, installation layout or environmental conditions. Product dimensions and locking quality should still be checked as part of the investigation.

Should SPC flooring be installed under kitchen cabinets?

A floating floor should not normally be restricted by heavy fixed structures unless the flooring system specifically allows it. The cabinet and flooring installation sequence should be confirmed before work starts.

How can importers reduce SPC installation complaints?

Importers should approve product samples, confirm specifications, provide the correct installation guide and require contractors to inspect the subfloor, moisture, layout, underlayment and perimeter details before installation.