waterfall leaks, need construction advice!
I've tried to make waterfalls several times and they always leak. My latest attempt: a 12" wide waterfall thing I bought, from a leading supplier. It sits on two thick slate "steps" that we just stacked. Then I sealed everything up with marine epoxy, and put all kinds of rocks on the sides and sealed them. After bolstering this with a ton of that black insulating foam also bought from a supplier (everything bought from justliners.com), it started leaking.
I cannot find the leak but when I reach my hand around the back of the rocks, it is leaking. I seal and seal and seal and foam and foam and foam and still it leaks.
Well last night my husband and I pulled everything apart and we want to start over. Unfortunately I have no extra liner to line everything with, but we might use a very very thick piece of plastic (the thickest dropcloth I could find at the hardware store). But then I want to seal those pieces of slate together like a sandwich, not just stack them and seal the edges, as I did last time.
Basically I would really appreciate any tips on the construction to make this baby WATERTIGHT for the first time in its life.
This waterfall is not even that tall: just two pieces of slate around three inches tall each, with the waterfall sitting on top (there's room for the reservoir because that is sort of sunk below into the ground).
I was thinking about concrete, or some kind of concrete mentioned by a few people at one point (I can't remember the adjective, for concrete or cement that is waterproof) as the "filling" for the slate sandwich. Something like a waterproof mortar?
So ---- VERY much appreciate all advice here.