# Epoxy Flooring — Coatings, Self-Levelling and Screeds

> Epoxy flooring is a resin flooring system applied to a concrete substrate, ranging from a thin sealing coat through self-levelling layers to a thick trowelled screed, with the system and thickness chosen by duty. Whether it lasts depends mainly on mechanical surface preparation and a dry slab; most epoxy failures are preparation failures.

## What it is

A **resin flooring system** applied to a concrete substrate, ranging from a thin
sealing coat to a thick trowelled screed.

| System | Thickness | Duty |
| --- | --- | --- |
| Coating | 0.2 — 0.5mm | Dust sealing, light foot traffic |
| Self-levelling | 2 — 3mm | General industrial, forklift traffic |
| Trowelled screed | 4 — 9mm | Heavy impact, chemical, thermal cycling |
| Anti-static | Varies | Electronics, clean rooms |

## Preparation is the specification

The finish is only as good as what it is stuck to. Required, not optional:

- **Mechanical preparation** — shot blasting or diamond grinding to remove
  laitance and open the surface
- **Moisture testing** to the system's stated limit before any resin is applied
- **Crack and joint treatment**, since movement joints must be carried through
  the resin, not covered over
- **Edge and upstand detailing**, including coving where hygiene requires it

Most epoxy failures are preparation failures, and they are visible within
months as peeling, bubbling or delamination in traffic lanes.

## Where projects go wrong

- **Acid etching instead of mechanical preparation.**
- **Applied to a green or damp slab.** Concrete needs its drying time.
- **Movement joints bridged**, so the floor cracks where the slab moves.
- **System thickness below the duty**, wearing through in aisles.
- **Applied in poor ambient conditions**, since cure depends on temperature and
  humidity.
- **Standard epoxy in daylight**, which yellows.

## Standards referenced

Concrete substrate requirements under **IS 456:2000**. Screed material
classification under **EN 13813**. Concrete protection products under
**EN 1504**.

## Frequently asked questions

### What thickness of epoxy is needed?

It follows from the duty. A thin roller-applied coating of roughly 0.3mm suits light foot traffic and dust sealing, self-levelling at 2 to 3mm handles forklift and general industrial traffic, and a trowelled screed of 4 to 9mm is needed for heavy impact, thermal cycling and aggressive chemical exposure. Specifying epoxy flooring without a system type and thickness is how a coating meant for a store room ends up in a forklift aisle.

### Why do epoxy floors peel off?

Almost always inadequate substrate preparation or moisture in the slab. Epoxy bonds mechanically to an open concrete surface, so laitance must be removed by shot blasting or diamond grinding — acid etching and simple cleaning are not sufficient. If the slab is also damp, vapour pressure pushes the coating off from beneath. Neither failure is a product defect, and both are entirely predictable.

### Is epoxy suitable for outdoor use?

Not generally. Standard epoxies chalk and yellow under ultraviolet light, so external applications look degraded within a season or two. Where a resin floor is needed outdoors or in daylight-flooded areas, polyurethane or a UV-stable topcoat over the epoxy build is the right specification.

## Sources

- [IS 456:2000](https://standards.bis.gov.in/website/published-standards/department-wise) — Plain and reinforced concrete — code of practice
- [EN 13813](https://standards.cencenelec.eu/ords/f?p=CEN:105) — Screed material and floor screeds
- [EN 1504](https://standards.cencenelec.eu/ords/f?p=CEN:105) — Products for protection and repair of concrete structures

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Source: https://hagerstone.com/materials/epoxy-flooring