Please help outdoor tub boulders and concrete

[B Rad]

Another project that I should have researched and spent more time in planning stages. I built a hot tub outdoor with a submersible stove. I hit solid Rock at 2 feet deep so I broke a layer of rock out and made a form for concrete. Below the form I used roofing felt that said waterproof but two layers overlapping. Bad idea. Then went up from there with large boulders and masonery mix. On outside on all the concrete I coated with flex seal. And then wrapped with more of the felt paper. I have finished and it losses a lot of water. At first tons of bubbles in floor I believe most is in floor and near the bottom. Oh yea for asthetics and feel I put many sandstone rocks in the slab and this was area of most bubbles. So it s leaving around rock to mortar. I am going to drain and try something to improve. One idea being aquarium silicone around the rocks and where slab meets Mason. I think also issue on outside where slab meets walls since there is a lap of of many seams of paper. Please help and input is valued but try not to be too hard on me. Thanks.

 

[Terry]

Most showers are done with a vinyl liner, as grout and mortar are not waterproof.

 

[Sponsor]

 

[Jadnashua]

To be successful, you really need to build something like this as if it were a pool, or a very deep shower pan. The materials you used will only slow the loss of water, not stop it. Leaking water constantly will also entice roots, carpenter ants, and termites.