Spa Spillway stone/leak repair [Archive] - Ceramic Tile Advice Forums - John Bridge Ceramic Tile


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08-01-2019, 01:10 AM
My stone on the spa spillway needs to be re-done. Water is seeping under the spillway stone when it is on. Here is my plan and looking for advice:

1. Remove stone, chisel and remove all grout, grind down previous mortar bed to exposed spa gunite shell.
2. Use injection epoxy to fill the seam between the mortar/rockwork and spa shell. (There are small voids in the wall which is where the water leaks when the spillway is on. The injection epoxy would fill these voids.)
3. Apply Hydra Ban to waterproof the any exposed gunite spa shell.
7. Use 254 Platinum Thinset to reset new spillway stone.
8. Use spectra epoxy grout to grout in the stone.

Thoughts or suggestions? I want a long-term fix to really make sure pool/spa water only goes where it is supposed to.

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08-01-2019, 02:42 AM
Welcome to the forum, fellow insomniac. :)

Only two potential issues I see. That doesn't mean there aren't others, so someone else may have more for you.

1. I don't know that gunite is an approved substrate for Hydro Ban. That's something I would call Laticrete Tech support for. It's not listed in the TDS. My guess is that it would be, but that's only a guess.

2. If there's a void between the stone and shell all the way around, you would have to waterproof up the sides of the spillway to keep water from simply running into the voids on either side.

08-03-2019, 06:22 PM
OK. All the old mortar has been removed and I have filled any voids between the gunite and stone/mortar with epoxy resin.

Next Question: Should I lay down a new mortar bed to level the gunite shell for easier flagstone installation?

1. Use 1 1/2" flagstone and just apply platinum 254 directly to the gunite and set the stone. The gunite is very rough and pitted so I would have to make a 1/2" to 3/4" thinset bed to have enough thickness to make sure the stone is level. (This doesn't seem like a great idea to me)

2. Use 1" flagstone and lay down a mortar bed to fill and level the spillway. Let that cure, then apply Hydro Ban to the mortar bed. Then use platinum 254 to adhere the flagstone.

What would you do? Am i missing anything?

08-03-2019, 08:21 PM
Your “fix” is not going to solve the issue you’re having and neither will mine. I do a lot of pool work with/for my father in law, it’s very typical to not have waterproofing on the shell or mortar beds behind the tile/stone. To get rid of the water spilling from the flatwork you’d have to get rid of the voids in the vertical setting bed so the water wouldn’t pool in the voids and in turn gush out or streak through. But that’s a can of worms not worth dealing with unless you’re ready to upgrade your scope of work significantly.

I’d forgo the epoxy and Hydroban. Mist the existing with water then fill in the divots with masonry mortar. Ditch those chopped up stones, go out and hand select some larger quartzite pieces, cut them to fit leaving a minimum of 1.5” overhang toward the pool. Then take some loose thinset and slurry coat your filled in mortar bed, set the stones with the same masonry mortar. After it’s set from overhead cut a 1/4” deep groove on the underside of the overhang about a 1/2” in from the edge to make a drip edge so the water doesn’t roll back easily onto the raised veneer.

The point of this is to minimize how much water gets into the voids behind the veneer, which will in turn minimize how much water will have to escape. This is your cheapest and fastest way to deal with your issues without having to open up that project upgrading can of worms.

08-03-2019, 10:51 PM
I know diddly about pools (although it looks nice) but the drip edge slot is a brilliant way to direct water off the face of the stone.

When dinosaurs roamed and sloped exterior sills were built into window frames, drip edges were common underneath those sills. Same principle as drip edge on roofs, too. Simple and effective.

08-05-2019, 03:12 AM
Thanks for the advice.

Why would you skip the Hydro Ban? Injecting the epoxy resin between the gunite and the stone mortar probably wasn't necessary but piece of mind for me knowing this area has no voids (or less voids) and the epoxy resin should bond the mortar and stone even better then before the epoxy resin was injected. It took 6 tubes of resin to fill the seam to the top.

Thanks for the advice on the stone. I went and bought bigger pieces of the flat stone we liked. Cutting the pieces to fit today.

I think I am going to follow your advice and fill in the divots and build up a mortar bed. Then apply the Hydro Ban. Laticrete tech said Hydro Ban is good over mortar. So once applied, water should not be able to penetrate the gunite or the mortar where the hydro ban is present, correct? Why do you feel water will still get in? Do you think the hydro ban will fail?

Once cured, I will use platinum 254, a modified polymer thinset at 3/16" depth(made for pools and to go over hydro ban) to set the new flat stone. Then I will use an epoxy grout to lock in the new flat stone and then run a silicone bead along the sides. I will cut the groove underneath the lip of the stone as you suggested.

If the spa side plaster and tile are waterproof, and the spa flat spillover is water proof (hydro ban) under the stone, and I use a modified thinset (254) to set the flat stone, and use an epoxy grout, where do you see water still being able to enter behind the veneer? Where do you think the failure will be? The spillover only runs about 10 minutes a day but I am curious from your experience on what will happen.

I am guessing the permanent larger fix is to remove all the spillway stone and completely waterproof the gunite wall, then redo the stone with the correct mortar? In 5-7 years when its time for new plaster, might be a great time to get this done if necessary.

08-05-2019, 07:32 AM
Sounds like you’ve come up with a solid plan. For pools we use a different waterproofing system or plaster seal to make things water tight. Hydroban will be fine, it just requires the mortar to cure beforehand. If you can set the stone with thinset, good on ya. I think what you're doing is the best thing that you can with the access that you have. Even might be overkill in a few ways, but that’s what makes it better.

Side note:
Is your pool and spa plaster?? We won’t drain the water down until we’re cleaning out when we’re working with existing plaster so we can refill the same time. The the plaster can fail from drying out and start to spall or crack. If you have pebbletec or similar drain downs are typically harmless.

08-05-2019, 11:13 AM
Thanks again for the advice.

Pool/Spa is plaster. Pool stays full. When I work on the spa I drain it, do the work, then refill it. Haven't let it sit dry for more then a day so far. It has been hot here so I have been worried about leaving the spa dry.

08-05-2019, 12:02 PM
Good deal! Relieved to hear you’re keeping it wet. Btw you’re saving some bucks doing the fix yourself. Please put finish pictures with the water running and beers in hand when you get to that point.

08-05-2019, 01:26 PM
Wow 6 tubes. So those were some pretty big voids that were filling up creating pressure head and a reservoir so water would drip out for a long time. can you explain the original problem did water squirt out from below the waterfall during a juice or afterwards or both? Or just seepage?

08-07-2019, 01:07 AM
The spa is about 5ft. above the pool waterline so it is a pretty large area.

Last summer I started to notice seepage through the veneer rock below the spillway when it was running. It was coming through the grout. The spillway runs about 10 minutes a day to change out the spa water. The water seepage would stop quickly after the spillover turned off.

This summer the seepage increased and it was easy to see that the flat stone on the spillway had come loose and the grout was wearing out. Any water that can get underneath the spillway flat rock will go down the wall behind the veneer stone and find its way out somewhere.

I hope epoxy, plus hydro ban waterproofs the spillover before I install the new flat rock. Then a mortar bed to install the new flat stone. Then a modified grout, then silicone the sides.

I'll post pics as I make progress. Cutting the new flat stone today to dry fit on the spillway.