Protective Linings for Cooling Towers & Basins

Correctly specified and applied Gemite cooling tower basin linings achieve service lives of 10-20 years, depending on the cooling water chemistry, biocide regime, temperature range, and quality of the initial application. The primary maintenance requirement is annual inspection of the lining for micro-cracking, edge delamination, and biological fouling - with spot repair as needed. Systematic replacement of the full lining is typically needed every 15-20 years. Unlined or poorly lined basins typically require major intervention every 3-7 years due to rebar corrosion and concrete spalling.

Lining application requires the cooling tower to be taken out of service, drained, cleaned, and dried before coating. Basin lining and repair work cannot be carried out with water in the basin or while the tower is in operation. For systems with multiple cells, a phased approach is possible - lining one cell at a time while maintaining cooling capacity through the remaining cells. Our project team works with the facility's cooling system engineers to plan the phased rehabilitation within available shutdown windows.

The primary deterioration mechanisms in cooling tower basins are: (1) carbonation - atmospheric CO₂ dissolves in the cooling water surface and attacks the concrete's alkaline matrix, lowering the pH and initiating rebar corrosion; (2) sulphate attack - from sulphate-based water treatment chemicals reacting with the cement matrix; (3) biological attack - algae and bacteria colonising the porous concrete surface, producing acids and creating surface roughness that accelerates further deterioration; (4) freeze-thaw - in outdoor towers in cold climates, the basin water level and packing zone surfaces undergo freeze-thaw cycling in winter. Gemite's lining systems address all four mechanisms.