Substrate & Preparation

Resin flooring systems are only as strong as the substrate beneath them.
Even the best epoxy or polyurethane system will fail if applied to a weak, damp, or poorly prepared surface.

Why Surface Preparation Is Critical

Most resin flooring failures are not product failures — they are preparation failures.
Skipping grinding, moisture checks, or repairs may reduce upfront cost, but it almost always leads to premature delamination, bubbling, or cracking.

  • Removes weak or contaminated surface layers

  • Creates a mechanical bond profile

  • Identifies cracks, laitance, and weak screeds

  • Reduces moisture-related failure risk

Close-up of smooth, glossy epoxy flooring in a modern industrial facility.
Close-up of smooth, glossy epoxy flooring in a modern industrial facility.
What Is a Substrate?

The substrate is the structural surface that supports the resin system.

In most cases this is a concrete slab or cement screed, but it may also include existing coatings or tiled surfaces.

Resin systems bond mechanically to the substrate. If the substrate is weak, cracked, contaminated, or affected by moisture, the resin system will fail regardless of its quality.

Technicians applying polyurethane coating in a spacious commercial area.
Technicians applying polyurethane coating in a spacious commercial area.

Common substrate issues are often present and can affect resin performance.

  • Cracked or poorly cured screeds

  • Rising damp or trapped moisture

  • Powdery or weak concrete

  • Oil, grease, or chemical contamination

  • Existing coatings with poor adhesion

  • Uneven or poorly finished surfaces

Technicians applying polyurethane coating in a spacious commercial area.
Technicians applying polyurethane coating in a spacious commercial area.
Technicians applying polyurethane coating in a spacious commercial area.
Technicians applying polyurethane coating in a spacious commercial area.
Common Substrate Issues
What Happens If Issues Are Identified?

Where substrate issues are identified, options are assessed based on long-term performance — not short-term appearance.

  • Mechanical removal of weak layers or coatings

  • Crack repair or structural remediation

  • Moisture mitigation or barrier systems

  • Alternative flooring recommendations

  • Deferring installation until conditions are suitable

Technicians applying polyurethane coating in a spacious commercial area.
Technicians applying polyurethane coating in a spacious commercial area.
Movement, Cracks & Joints

Resin flooring systems are rigid and will reflect movement from the substrate below.
Cracks, joints, and areas of structural or thermal movement must be correctly identified and treated during preparation.

If movement is not properly accommodated, it may result in:

  • cracking within the resin system,

  • joint telegraphing through the finished surface,

  • localised debonding in high-stress areas.

Correct treatment depends on the type of movement present, the function of the joint, and the system selected.

Technicians applying polyurethane coating in a spacious commercial area.
Technicians applying polyurethane coating in a spacious commercial area.

Not all floors are immediately suitable for resin systems.
Where serious substrate issues exist, proceeding without correction would compromise performance and lifespan.

  • Severe moisture issues without mitigation

  • Structurally unsound slabs or screeds

  • Unstable or poorly bonded existing coatings

  • Conditions outside system performance limits

In such cases, additional preparation, an alternative system, or deferred installation may be required until conditions improve.

When Resin Flooring Is Not Suitable

Not Sure If Your Floor Is Suitable?

If you’re unsure whether your existing floor is suitable for resin, we recommend starting with an expert floor review before any work proceeds.