The short answer
Epoxy for hard-working dry floors, polyurethane where there is sunlight or a little movement, PU screed for wet process areas with hot wash-downs, MMA where an area cannot close for long, and an acid lining where chemicals reach the concrete. Every one of them depends on proper surface preparation first.
The systems side by side
| System | Best for | Main strength | Watch out for |
|---|---|---|---|
| Epoxy | Warehouses, workshops, factories, gyms | Very hard, bonds strongly to prepared concrete, easy to clean | Standard epoxy can yellow in sunlight |
| Polyurethane | Sunny areas, retail floors, showrooms, refurbished warehouses | Slightly flexible; UV-stable grades hold their colour | Needs sound, well-prepared concrete like any coating |
| PU screed | Food and beverage plants, commercial kitchens, wash-down areas | Takes hot wash-downs, fats and heavy wear | A thick, trowelled system, not a thin coat |
| MMA | Truck stops, ablutions, loading areas, sites that cannot close | Cures fast, so downtime stays short | Strong smell while it is applied |
| Acid lining | Sumps, trenches, tank plinths, chemical floors, battery rooms | Chosen for the chemicals on site | Must match the chemicals, concentration and temperature |
| Decorative cement-based finish | Homes, showrooms, offices, restaurants | Stone-like look with minimal joints | Needs a sound, level base and a sealer |
What decides the choice
The traffic (feet, trolleys or forklifts), the chemicals and their concentration and temperature, hot water and steam cleaning, sunlight, and how long the area can be out of use. A site visit answers most of these.
Many floors combine systems
An epoxy primer and body coat under a UV-stable polyurethane topcoat is common, so the floor gets the bond of one and the colour stability of the other.
