The client wanted to create a water tank and run existing down-pipes into it for use on his garden and ponds. The water tank needed to have a membrane applied. The problem we had was that the walls were not constructed strong enough to have the usual membranes. We recommended to use a fiberglass system which was able to accommodate movement as well as being strong enough to cope with the volume of water.
Fibreglass Matting, Resin, Potable Drinking Standard Jell Coat