Epoxy terrazzo can be applied to rough, unfinished floors, but strict substrate conditions and special processing techniques are required. Otherwise, cracking and delamination are likely to occur. Specific requirements and processes are as follows:

I. Prerequisites for Rough Floor Application

Substrate Strength Requirements

The rough floor must be solid and free of hollow areas, with a compressive strength ≥25MPa and no severe sand or dusting. If the substrate is loose, it needs to be re-poured with concrete or repaired and reinforced with high-strength crack-resistant mortar.

Moisture content must be ≤8% (no condensation should be observed using the thin-film method). If the humidity is too high, the drying time needs to be extended or a moisture barrier layer added.

Smoothness and Defect Handling

Flatness error ≤3mm/2m. Areas exceeding this standard need to be mechanically ground to remove bumps, and depressions should be filled with epoxy mortar.

Cracks are cut into V-shaped grooves and filled with epoxy mortar and reinforced with fiber cloth; expansion joints are filled with special sealing strips.

II. Key Construction Process Adjustments

Strengthening the Crack-Resistant Layer

Apply two coats of solvent-free epoxy primer (increasing the dosage to 0.3 kg/m²) to seal pores and improve adhesion.

Lay a full layer of fiberglass mesh (overlapping 250px), then apply primer to fix it, forming a tensile skeleton layer.

If conditions permit, add a PE release film + crack-resistant mortar leveling layer to completely block stress transmission from the base layer.

Aggregate Laying Optimization

Adopt the "zonal progressive laying method," prioritizing the construction of complex pattern areas, with an interval of at least 4 hours between adjacent color blocks to prevent color bleeding.

Increase the aggregate thickness to 8-10 mm to improve impact resistance; use a vibratory trowel to remove air bubbles after laying.

Grinding and Sealing

After coarse grinding, a "two-stage grouting process" is used: first, epoxy intermediate coating + 100-mesh quartz sand is used to fill the pores; second, fine quartz powder is used to seal the micropores.

Before applying the finish coat, spray an epoxy terrazzo-specific sealant. After polishing, the gloss level should reach 60-70°.

III. Prohibited Scenarios and Alternative Solutions

Situations where direct construction is prohibited:

Insufficient substrate strength (dusty when stepped on), moisture content >12%, or water seepage.

Areas with heavy vehicle traffic without a concrete reinforcement layer.

Alternative Solutions:

For dusty surfaces, a sealing and curing agent can be applied to increase hardness before applying epoxy terrazzo; severely damaged substrates must be removed and re-poured.