The existing EPDM tank liner was no longer water tight, which had resulted in the flooding of the basement. Secondly because the tank was no longer holding firefighting water, the property owner had to put in place additional fire watch arrangements.
Firstly we removed the existing liner by cutting it out and rolling it up in to pieces that could be easily handled. Beneath the old liner was approximately 3 Tons of saturated wet sand that had to be contained in rubble sacks and removed from within the tank.
To ensure good adhesion of the new tank lining all concrete surfaces were prepared by method of vacuum controlled diamond grinding.
The corroded steel fittings were prepared to St 2 as per ISO8501-1 by method of needle gunning and tungsten carbide scraping to remove loose corrosion and scale present.
To prevent future corrosion all steel components within the tank were primed using Corroless EPF rust stabilising epoxy primer. Corroless EPF contains a mined pigment that converts corrosion present to stable iron oxides such as magnetite. Corroless EPF also contains self-leafing glass flake which laminate within the coating to provide a more tortuous route for oxygen and moisture to reach the steel substrate, offering improved corrosion resistance.
All corners were rounded using a polyurethane jointing compound and reinforcement bandages applied to all construction joints within the tank.
Corrolastic SG was then applied by method of slurry brush and trowel to a thickness of 3mm throughout the tank. Corrolastic can crack bridge up to 2mm and remains fully flexible when cured.
Corrolastic SG can be applied to matt damp surfaces, making it ideal for the application to concrete surfaces such as those found here.
Because the material has a grout like consistency it can fill blow holes up to 5mm without the requirement for an additional fairing coat or filling operations.