Delamination or Surface Scratch: How to Tell the Difference

A surface scratch changes only the appearance of the top skin and leaves the panel stiff. Delamination separates the skin from the core, so the affected area flexes, sounds hollow when tapped and can be pressed down with a thumb. A scratched panel can stay in service; a delaminated one should be removed because it no longer spreads load and can catch a wheel.

This page covers delamination vs surface scratch in six sections: Delamination and how to tell it from a; Crushed cores: what local crushing looks like; Repairing panels instead of replacing them; Diagnosing a damaged floor and working out the; The cost of a single damaged floor; Writing a defect report that gets a useful. Each section answers one practical question and can be read on its own.

Key facts

• Delamination is the separation of a face sheet from the core, and it is confirmed by looking at the edge of the separated area rather than …
• Local crushing shows up as a sharp permanent indentation under a single point, and it means the core height at that spot was never adequate for …
• Most damaged panels can be repaired, and in a fleet with a planned maintenance step that is usually cheaper than replacing them.
• The pattern of the damage tells you what happened, and reading the pattern is faster and cheaper than replacing the floor and hoping it does not …
• One damaged hardwood or marble floor typically costs more than the entire protection budget for the project, which is the clearest argument for specifying it properly.

Delamination and how to tell it from a surface scratch

Delamination is the separation of a face sheet from the core, and it is confirmed by looking at the edge of the separated area rather than the surface.

A scratch on the facing is superficial and changes nothing structural. A delamination shows a lifting skin with a visible gap beneath it, and the panel flexes differently under hand pressure in that area compared with the sound part of the panel.

Adhesive-bonded panels are more susceptible, particularly in warm, wet conditions, because the adhesive line is the part of the panel with the least tolerance for differential movement. Welded-bond panels rarely delaminate because the failure would require tearing the material itself.

A delaminated panel should be withdrawn from use in the affected area, because the lifting skin is a trap for grit and the panel has lost stiffness locally. It is also a useful diagnostic: repeated delamination in the same product points to a bonding process issue rather than to site misuse.

Crushed cores: what local crushing looks like

Local crushing shows up as a sharp permanent indentation under a single point, and it means the core height at that spot was never adequate for the load.

The difference between an acceptable deflection and a failure is whether the deformation is permanent. A panel that recovers to flat when the load is removed has flexed, not failed. A panel that keeps a dent has had its core walls buckle.

Buckled core walls do not recover, and the crushed region has lost most of its capacity. A panel with a crushed area should come out of service rather than be monitored, because the load path around the damage now concentrates on the adjacent cells.

The corrective action is almost always to spread the load rather than to buy a heavier panel everywhere. A spreader plate under the offending item, or a thicker board locally, resolves the problem at a fraction of the cost of upgrading the whole area.

For terminology and test-method context see ISO standards catalogue. The guidance on this page is practical site guidance, not a test report or a certificate.

Repairing panels instead of replacing them

Most damaged panels can be repaired, and in a fleet with a planned maintenance step that is usually cheaper than replacing them.

A puncture in the face is a patch job. Clean the area, dry it, and apply a compatible patch larger than the hole, sealed around the edges. The patch needs to be a material that bonds to the facing and that will not become a hard spot under traffic.

A crushed core cannot be repaired, because the internal structure has been permanently deformed. That panel can only be used on a lower duty, such as a vertical wall covering or a storage cover, and it should be marked so that it is not returned to a load-bearing role.

A cracked face with a sound core can often be recovered by trimming back to sound material and protecting the exposed edge. Recording the repair on the panel’s own history, so that a repaired panel is accounted for in the inspection regime, is what keeps the fleet trustworthy.

Diagnosing a damaged floor and working out the cause

The pattern of the damage tells you what happened, and reading the pattern is faster and cheaper than replacing the floor and hoping it does not happen again.

A linear scratch following a straight line across the floor usually indicates a single sharp object dragged along the surface, often a trolley wheel running over trapped grit or a board edge lifted above the surface.

Circular or arc-shaped damage points to a rotating object under load, such as a castor. A cluster of impact marks in a small area suggests something was dropped, and the shape of the marks gives an indication of the object and the height it fell from.

Damage that follows the line of a joint or a panel edge points to the protection rather than to the site activity, because the edge lifted and then cut. This pattern is worth recognising because the remedy is to change the joint treatment, not to change the traffic.

The cost of a single damaged floor

One damaged hardwood or marble floor typically costs more than the entire protection budget for the project, which is the clearest argument for specifying it properly.

The cost is not the repair. A scratch in a hardwood floor needs sanding and refinishing; a chipped marble tile needs replacement and the whole batch has to be matched; a damaged resin floor needs a specialist repair system. The cost sits in the specialist trade and the disruption.

The second cost is time. The area has to be closed, the finish stripped back, and the trades that were waiting behind it have to be rescheduled. On a fit-out programme, damage to a client floor can cost several days.

The third cost is the relationship. A damaged client floor generates a formal claim, and the resolution involves everybody involved in the project. This is the cost that rarely appears in a protection budget but is consistently the largest.

Writing a defect report that gets a useful answer

A defect report that names the panel, the batch, the location and the failure mode produces a replacement or a credit; a report that says the panels are faulty produces a dispute.

The first element is identification: the product name and grade, the batch or production date, the order reference, and the panel’s own mark if the fleet is numbered. Panels that are individually numbered make this trivial and are worth doing in any reuse programme.

The second element is the failure mode, described in physical terms rather than as a complaint. Saying the panel failed at a 4 mm working deflection under a 1500 kg per square metre load describes the mechanism and tells the supplier whether it is a design issue, a manufacturing issue or an application issue.

The third element is the evidence: photographs of the failed area, the panel edge in section, and the substrate beneath. A photograph of a sectioned edge is worth more than a description, because it shows the core structure and the bond line directly.

Frequently asked questions

Can a delaminated panel be repaired on site?

Delamination is the separation of a face sheet from the core, and it is confirmed by looking at the edge of the separated area rather than the surface. A scratch on the facing is superficial and changes nothing structural. A delamination shows a lifting skin with a visible gap beneath …

What does a hollow sound under the skin mean?

Local crushing shows up as a sharp permanent indentation under a single point, and it means the core height at that spot was never adequate for the load. The difference between an acceptable deflection and a failure is whether the deformation is permanent. A panel that recovers to flat when …

How do I work out what damaged the floor?

The pattern of the damage tells you what happened, and reading the pattern is faster and cheaper than replacing the floor and hoping it does not happen again. A linear scratch following a straight line across the floor usually indicates a single sharp object dragged along the surface, often a …

What does a single damaged floor actually cost?

A defect report that names the panel, the batch, the location and the failure mode produces a replacement or a credit; a report that says the panels are faulty produces a dispute. The first element is identification: the product name and grade, the batch or production date, the order reference, and the panel’s own …

Sources and further reading

• ISO standards catalogue: plastics test methods, including ISO 178 flexural properties and ISO 844 compression of rigid cellular plastics — www.iso.org
• UK Health and Safety Executive: construction safety guidance — www.hse.gov.uk
• ASTM International standards catalogue for plastics and cellular materials — www.astm.org
• PlasticsEurope: polypropylene material properties and recycling information — plasticseurope.org

References checked by publisher and title on 2026-11-06. Standards and regulations are cited by name only; no performance values are attributed to them. General material-property figures in the text are indicative reference values for polypropylene and should be verified against your supplier’s current data sheet. Confirm applicability and current versions for your own project before relying on any of them.

Related Mingskye protection panels

• Heavy Duty Reusable PP Protection Panel for Construction Flooring Walls and Stairs
• PP Honeycomb Protection Board with Felt Layer for Construction Site Surface Protection
• Reusable Plastic Construction Protection Sheet with Felt Surface for Building Renovation

For a quotation, a sample panel or help matching a thickness and facing to your site conditions, contact service@mingplastics.com or WhatsApp +86 189 3887 1524. Include the surface type, floor area, the trades working overhead and the expected duration so the recommended specification can be confirmed before you order.

Final takeaway

For delamination vs surface scratch, Keep a condition record and an inspection rhythm so a failure can be diagnosed rather than guessed at. A defect report that names the panel, the batch, the location and the failure mode produces a replacement or a credit; a report that says the panels are …