Common Epoxy Floor Problems

Bubbling and Blistering

Bubbles appear as raised circular areas ranging from pinhead size to several centimeters. They form when gases become trapped beneath the coating during application or cure. Common causes include:

• Outgassing from porous concrete
• Rising substrate temperature during application
• Excessive coating thickness in single application
• Mixing introducing air into material
• Application during falling temperatures

Prevention requires proper timing and technique. Apply primer during falling temperatures when concrete pores contract. Use slow-speed mixing (300-400 rpm) and allow mixed material to stand before application. Spike rolling immediately after application releases trapped air.

Repair involves grinding affected areas to sound substrate and reapplying the system. Small bubbles may be sanded and overcoated if adhesion remains intact.

Delamination and Peeling

Delamination manifests as coating separation from substrate or between layers. It typically starts at edges or areas of high stress. Tapping produces hollow sounds indicating bond failure.

Primary causes include:

• Inadequate concrete grinding services
• Moisture in substrate (>4% content)
• Contamination between coats
• Exceeded recoat window
• Incompatible primer/coating combination

Solutions require complete removal of failed coating to sound substrate. Address underlying causes before reapplication. Moisture barriers may be necessary for damp substrates.

Yellowing and Discoloration

Color changes affect aesthetics and may indicate chemical degradation. Standard epoxy yellows under UV exposure - unavoidable without UV-stable topcoats. Additional discoloration causes:

• Chemical attack from spills
• Incorrect mixing ratios
• Amine blush from humidity
• Rubber tyre marking
• Heat exposure above design limits

Prevention involves proper product selection. Aliphatic polyurethane topcoats provide UV stability. Chemical-resistant formulations prevent staining from spills. Proper mixing and environmental control during installation prevent initial discoloration.

Cracking and Crazing

Cracks appear as linear breaks following stress patterns. Crazing creates interconnected surface cracks resembling dried mud. Both compromise protection and appearance.

Repair depends on crack depth and cause. Surface cracks may be filled and overcoated. Structural cracks require routing, flexible filling, and possibly reinforcement.

Soft or Tacky Surface

Incomplete cure leaves surfaces soft, tacky, or easily marked. This severely compromises chemical resistance and durability. Causes include:

• Incorrect mixing ratio (usually insufficient hardener)
• Inadequate mixing of components
• Temperature below minimum cure requirements
• Expired or compromised materials
• Moisture contamination of components

No effective repair exists for improperly cured epoxy. Complete removal and replacement is necessary. Prevention requires accurate measuring, thorough mixing, and suitable environmental conditions.

Fish Eyes and Craters

Circular depressions where coating pulls away from contamination points. Size ranges from 1mm to several centimeters. Common contaminants include:

• Silicone from sealants or sprays
• Oil from compressed air lines
• Wax from previous floor treatments
• Residual release agents on new concrete

Prevention requires thorough decontamination before coating. Solvent wiping, detergent washing, and test patches identify problems. Once occurred, affected areas need grinding and spot repair.