Welded pond liner?

Hi folks,

I am planning to build a circular pond and was wondering if anyone can
comment on preformed 'welded' butyl liner? A few companies say they can
do this and it sounds like it might be what I'm looking for. The
dimensions of the pond are radius 1500mm, depth 600 with a 200mm deep
shelf. One part will be slightly overhung by decking.

If I use a flat piece of liner there will be lots of folds so was
wondering if the preformed liners are any good? Are there and potential
problems?

An alternative I have been advised is to build the pond in concrete
with bituminous coating. Someone else then commented that certain fish
might not like the coating? I don't plan on havig Koi. Probably
goldfish, orfe and the odd tench or ghost carp.

Thanks in advance!

Gary.


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GaryCampbell