case studies - Covac Completion Reports
For detailed documentation of some Butyl and PVC water storage tank liner repair and refurbishment we have completed, please see the case study link below.
Butyl bags tend to be used for a ‘quick fix’. They are, essentially flexible liners that are suspended from the top of the tank (usually by aluminium strips). They do not address the problem of corrosion in the structure especially the roof, which usually remains completely unprotected, allowing the risk of contamination from bacteria (including Legionella) when condensation forms and drips back into the potable water. COVAC are usually called in to urgently rectify jobs where these liners have been installed because they are generally quite flimsy and once even the slightest damage occurs, the water in the structure traverses through the damaged area (even a small ‘pinhole’) causing ingress of water between the substrate and the liner.
This usually results in water stagnating behind the liner causing a risk of bacterial growth and eventually, pushing the liner to the top of the tank and causing the tank to overflow.