Hi, when i have a client asking for a pool I usually send them to specialist pool builders in the Gambia who use the fibreglass method, they seem to be working better to be honest. I have never built a pool myself but I know a lot of pools built from before the fibre glass coating method came into Gambia and they had leakage problems, I suspect this is due to 1, bad workmanship, 2,lack of technical know how which leads to the wrong kind of materials used. If you have a good knowledge of how to build pools from reinforced concrete and have the right materials (water proofing) I am sure it can be done.