Pool Leak at Tile Line

[PatG25]

Hi All

I have a 22,000 gallon gunnite pool and have been fighting pool leaks for the last couple of years. I found a broken pool supply pipe (the pavers were sinking and gave it away) and permanently closed my hydrostatic valves last year (they always leaked; they opened up in the spring and never closed because something always got stuck in them). Well, the pool is still leaking. I finally gave up and called in leak detection experts (pretty expensive). They found that the spa return line was leaking (where the jets are?), could be in multiple places. They had listening equipment and pointed to the line where it enters the spa. The outside of the spa had white stuff on it which I guess is calcium (??) that build up when water seeped out of the spa from the leak. At least that is what they are telling me.

When they did the pressure test they also noticed air bubbles coming out of the gunnite / tile line; i.e. where the gunnite meets the tile. They confirmed with a soap spray solution and I also saw bubbles coming out. Now that blew me away as I thought the tile is only decorative!! But if air can come out of a crack then water can go into the crack (and out of the spa). Visually I can't see anything wrong. I closed the spa jets and turned off the spa supply, but I guess the pool is plumbed where the pool supply also goes to one other spa supply line. So the spa waterfall was going like it normally is. At night the pool turned off and in the morning the water level had dropped to the tile / gunnite line. I guess that would confirm it.

So my questions:

• I guess the tile in not decorative? How would I fix the leaks? Remove, replace and re-grout? Try to use a silicon sealer on it? Using a silicon sealer I can do, re-grouting - no way, would need to call another expert in.
• How does a pipe run in the spa; how do I get to it? The spa is tile on the outside and gunnite / tile on the inside? But if the tile is not decorative then I guess that's the way to get at it?
• If the tile can leak, do I check my entire pool tile / gunnite line ever year? This now has me really worried as it would be hard to detect a leak there. Is this a normal place where a gunnite pool can leak??

Thanks,
Pat

 

[ajw22]

Tile is water proof but the grout lines around it easily develop cracks that let water in. Good pool builders put a waterproof membrame on the gunite before the tile and plaster layers are applied. Like Basecrete

To get to pipes in the spa walls takes removing the tile and hammering into the gunite to expose it.

The outside of the spa has efflorescence. That is salt and calcium carried by water coming through concrete. Concrete and gunite is porous and water flows through it.

Where you talk about gunite I think you mean plaster.

Post some pics of your spa and the problem areas.

@bdavis466 may have some thoughts.

 

[chemillion]

Tile is water proof but the grout lines around it easily develop cracks that let water in. Good pool builders put a waterproof membrame on the gunite before the tile and plaster layers are applied. Like Basecrete

To get to pipes in the spa walls takes removing the tile and hammering into the gunite to expose it.

The outside of the spa has efflorescence. That is salt and calcium carried by water coming through concrete. Concrete and gunite is porous and water flows through it.

Where you talk about gunite I think you mean plaster.

Post some pics of your spa and the problem areas.

@bdavis466 may have some thoughts.

@ajw22 What kind of waterproof membrane is applied to the gunite before the tile and plaster layer is applied? Is the waterproof a chemical sealant or a type of sheet membrane? Is there a specific type of waterproofing for glass tile vs. porcelain tile?
Thanks!

 

[bdavis466]

It's a cementitious waterproofer like Super Blokade or HydroBan. Sometimes Redguard is used. The waterproofing behind the tile is to prevent the tiles from eventually falling off, not necessarily preventing a leak.

It would be very uncommon for there to be a leak at the tile line unless the pool shell was somehow damaged. 96.5% of the time leaks occur at the penetrations into the pool or the plumbing.

 

[PatG25]

Here are some pics of the spa. The pipe leak was detected at the top of the spa at the corner where the steps meet the top level pavers.

So you are saying that the efflorescence is normal, just water seeping through the gunnite and out the tile? With the spa jets plugged and the pool running about 8 hours each of the last two days I still am losing about 0.5" per day. It has been very hot (high 80s in the northeast) so I think about 0.25" is due to evaporation. But that would mean I lose 0.25" through the tile? I did a dye test last night and did see some of the dye disappearing by the plaster but 0.25" on a 22,000 gallon pool still seems like a lot? Or is it?

Next step is to completely shut down the spa, drain the water and plug the spa supply to see if the water loss stabilizes to what can be evaporation. I''ll do a bucket test at the same time.

 

[sktn77a]

That's not efflorescence - it's a leak. The leaking water is evaporating and leaving the salt content (calcium, etc) on the side of the spa.

 

[PatG25]

Yes, I thought the pool is leaking. Question now is it the pipe in the spa are also between the plaster and the Tile. I called the pool builder and they will come out next week as my pool is 10 years old and I wanted some upgrades (i.e. new lights). But now the pool builder is telling me that it is recommended that a pool needs new plaster after 7-10 years. Could that be a source for leaking? I did a bucket test on the pool after the pool leak detection people told me everything is fine and the bucket test shows that the pool is down at almost twice the rate of the bucket (after about 2 days). So with everything else eliminated that leaves the pool / plaster line and the plaster itself.

Where do I go from here?

Thanks!

 

[chemillion]

It's a cementitious waterproofer like Super Blokade or HydroBan. Sometimes Redguard is used. The waterproofing behind the tile is to prevent the tiles from eventually falling off, not necessarily preventing a leak.

It would be very uncommon for there to be a leak at the tile line unless the pool shell was somehow damaged. 96.5% of the time leaks occur at the penetrations into the pool or the plumbing.

@bdavis466 what are the proper steps (& cure times for each) for installing glass waterline tile?
1. BaseCrete (24 hrs)
2. Hydroban or SuperBlockade (3 days?)
3. Thinset & Tile (3 days)
4. Grout?

Why I am hearing some tile installers say the proper way takes about 3 weeks for glass tile and some say 1-3 days? (taken into account size and complexity, but typically for a curing time purposes)

Thanks

 

[bdavis466]

You'll have to see what your tile manufacturer wants.

Oceanside tile and Lightstream Tile basically want 28 days between each phase of the process... others aren't as stringent

 

[PatG25]

 

[Rocco]

If I understand correctly the lowest you saw the water go was approximately 12" below the skimmer, is this correct? If so it is possible that the skimmer line has a leak and the main drain is tied into the skimmer line which allows the water to drop below the actual skimmer box. I recommend plugging the skimmers, fill the pool with water a bit if needed, and see if the leak continues.

If you suspect it is the skimmer you could remove a the pavers around it and dig a bit to see if you reach water.

 

[PatG25]

Well, thanks for the advise. I guess that is possible but what will plugging the skimmer line do? If the leak is somewhere in that line the water is still going to leak, right, even with plugging the skimmer?

 

[PatG25]

Anyone else have anymore thoughts on this?