Need help waterproofing and tiling pool, not on concrete.

[njannsen]

This is my second go around. I have a plunge pool (5' wide by 11' long 7' deep)I made it out of cinderblock, reinforced with rebar and filled with concrete and I asked around and redguard was the waterproofing I landed on. Then we cover the pools with 12 x 24 ceramic tile and river rocks on the bottom. I have had it for two years and it looses water, sometimes slow, sometimes 8" in a night. The bottom river rock tiles are on a concrete bed of about 5 inches. The pipes don't seem to be the problem as it loses even when its below the jets.
I want to take the tile off and the floor and do it over in Kerdi. Does anyone think that will work?
Lots of mistakes with this first go around but want to get it right as the pool is very enjoyable. Any help is appreciated, thanks.

Neil

[dhagin]

Hi Neil.

Moved ya over here as this is where project threads go. Your idea should work fine. After you get all the tiles off the walls and floor, I'd grind it all back to clean and bare block. Make sure to follow all the Kerdi install instructions and do a flood test (leak test) after all the Kerdi is done, before setting any tile.

[Lakee911]

I know Kerdi will work for a pool, but does Schluter condone it?

Seven feet of head on a bottom kerdi seam is far more than one would see in a typical shower. Is there any other procedures that need to be followed (like maybe more overlap or set in kerdi fix in lieu of thinset)?

[madmantrapper]

Seven feet of head is only about 3 pounds per square inch.

[njannsen]

We were wondering about the pressure as well and thought that some of the grout at the bottom could be under too much stress.
It sounds like a good plan, really don't feel like doing this again. Anyone else see any issues, problems. Use aquaguard as well?
Thank you.

[Lakee911]

Originally Posted by madmantrapper

Seven feet of head is only about 3 pounds per square inch.

Agreed. That's still 40x more pressure than one would see in a shower.

Originally Posted by njannsen

We were wondering about the pressure as well and thought that some of the grout at the bottom could be under too much stress.
It sounds like a good plan, really don't feel like doing this again. Anyone else see any issues, problems. Use aquaguard as well?
Thank you.

I'm not concerned about the grout because one does use that in a pool and it holds up fine. Make sure that whatever grout you use is rated for prolonged submergence. Laticrete has some good products.

It's going to be critical that you get 100% coverage under all tiles, though. You don't want any voids under any tile...or in the grout.

If you don't mind me asking, what does one do in such a small deep pool? Hop in, tread water, hop out?

[dhagin]

To satisfy your curiosity, send Schluter Tech Support an email asking about your project. Let us know what they say.

[njannsen]

Thanks for all of the info. With that pressure I was wondering if thin setting the seams would be the path or I heard there was a "caulk" that schluter has for heavy duty seams? I will send it over to tech support at schluter and see what I come up with.
I get a lot of questions (and some laughs) about the use of the pool. I think a lot of times you just jump in a pool to cool off so it is great for that. The depth makes is good for diving and my two boys love it, plus because of the size it is easy to take care of, except the leaking. I got the idea from plunge pools they use in bathhouses that are really cold.

If anyone else has suggestions or critiques of schluter for this application I would love to hear them.
Thanks again,

Neil

[Tool Guy - Kg]

Welcome to the4 forum, Neil.

I'm nearly positive that Schluter has tested Kerdi to 14' of head pressure using their ordinary installation directions and using the typical high quality unmodified thinset for the seams. You've got no concerns.

[jerrymlr1]

8" of water in one day? Sounds like you might have a structural problem to me. You should do a leak test with food coloring and find out where the leak is. I would check the light niche and all the penetrations, inspect all the corners, then the walls for cracks. Might need an underwater light and some scuba gear.

[sepulchral]

If there is no damage when it leaks to other structures i would focus on fixing the leak. You need to evacuate and inspect. Fill 6" mark the spot check to see if level drops. Increase another 6" mark spot and so on. This is assuming you have a leak on a side wall

the hydrostatic pressure 8psi + 14psi atmospheric. So you have 22psi at a 7ft depth. Pushing outwards on all four walls with a full pool. You could have a structure issue.

Next go around bend a curcumferential cage and formwork the walls versus block. Do one concrete pour over a slab that has rebar on the perimeter protruding into the cage. Or buy a tall preformed concrete septic tank

[Steve in Denver]

Originally Posted by sepulchral

the hydrostatic pressure 8psi + 14psi atmospheric.

We have different numbers floating around for how much pressure at 7 feet. Someone suggested 3 pis, which jibes with this:

http://www.engineeringtoolbox.com/hy...er-d_1632.html

I would think the atmospheric pressure is a non issue as it is equally present on the outside as the inside.

Still, 3 psi over that much area would be a significant amount of force...

[jerrymlr1]

My thinking wasn't so much the water pressure but that 7' of block needs to be sitting on a good footer and steeled in completely with the footer and floor.

[fdanielson]

I re-read the first post a couple of times and is says the floor is river rock on about 5 inches of concrete. Is there Redgard on the floor or just the walls?