THE PROBLEM
The two new sprinkler tanks required a suitable tank lining to ensure fluid tightness of these concrete tanks.
Sprinkler Tanks Lining, Farringdon London
THE SOLUTION
We proposed the application of a proven crack bridging epoxy tank lining from Remmers
Initially all surfaces were prepared by method of vacuum controlled diamond grinding to remove surface laitance in order to ensure excellent adhesion of the new tank linings. Laitance is a weak friable layer that forms on the surface and mould faces of concrete, which if tank linings are applied to will lead to premature tank lining failure as this layer separates/flakes away from the main body of concrete.
By removing the surface laitance extensive blow holes were exposed in the concrete. These cannot be filled with coatings alone! Therefore as per best tank lining practice a fairing coat of Remmers WP Sulfatex was applied by method of slurry brush to fill these prior to the application of the tank lining. This fairing coat was left as a brush finish to provide a mechanical profile to provide optimum adhesion for the subsequent epoxy tank linings.
The same material was mixed with kiln dried quartz to form a fillet cove detail at the floor/wall interface. This is the part of the tank most liable to move and the application of a cove detail serves to isolate this potential point of movement and act as an elongation multiplier for the tank lining.
The fairing coat was allowed to cure and hydrate naturally before introducing dehumidification to ensure the correct climatic conditions and moisture content of the substate for application of the epoxy tank lining system.
As part of our standard tank lining quality assurance the moisture content of the substate was checked using a Tramex moisture meter and the climatic conditions tested and recorded prior to tank lining application.
Remmers Epoxy MT100 was used to prime all surfaces. This highly damp tolerant epoxy primer can be applied to substrates with a moisture content of up to 6%, ensuring excellent adhesion of the new tank linings
Once cured Remmers Epoxy WHG was applied in two coats at 0.5Kg/m2 per coat to all surfaces to be coated in the sprinkler tanks. This crack bridging epoxy tank lining is ideal for lining concrete tanks as it can crack bridge to 0.2mm, which is a common standard crack width design for concrete structures.
To ensure a pin hole free finish and as part of our standard tank lining quality assurance the cured tank linings were tested for porosity using a DC holiday spark tester. By running a high voltage (but low current) through a copper brush and breaks or ‘holidays’ in the tank lining are identified. These are marked prior to touching in using the same material to ensure a seamless tank lining.