Polyurea Coating for GRP Tank

Introduction

Six GRP wastewater tanks had deteriorated significantly over five years without maintenance, developing structural cracks that allowed wastewater and contaminants to leach into the surrounding soil. The resulting environmental risk demanded urgent remediation, including both structural repair and a robust long-term protective lining solution.

Our Solution

UCL operatives conducted a full structural survey of all six tanks, identifying cracked and damaged areas before replacing deteriorated fibreglass around the plinth and housing. Additional crack injection resin repairs were carried out where further defects were found during inspection. Tank interiors were abrasive blasted to remove contamination and surface oxidisation, then washed and rewashed with demineralised water to eliminate residual mineral content. A primer was spray-applied prior to the installation of a 2 mm thick coat of HTF100F UB pure polyurea — a waterproof, high-performance lining system with exceptional elongation and tensile strength. The system fully encapsulates all joints and fittings. Upon completion, all coated surfaces were subjected to high-voltage spark testing to identify and immediately repair any pinholes or holidays, ensuring a continuous, watertight membrane.

Key Benefits

• Structural integrity restored across all six GRP tanks through resin crack injection and fibreglass patch repairs
• Contamination of surrounding soil halted, eliminating the environmental risk
• 2 mm HTF100F UB polyurea lining provides a 50-year design life expectancy
• Full encapsulation of joints and fittings delivers a watertight, flexible membrane resistant to positive pressure and movement
• High-voltage spark testing verified coating continuity with zero holidays remaining post-repair
• Demineralised water rinse ensured a contaminant-free substrate prior to coating application

Conclusion

All six GRP tanks were returned to service with a continuous polyurea lining rated for 50 years. UCL Ltd provides end-to-end tank remediation — from structural repair and surface preparation through to specialist coating and independent quality verification.