Travertine and water feature sinking/cracking! Seeking TFP input!

[ts2018]

Seeking all suggestions on our 1 year old pool construction! I should start by noting that the builder has agreed to remove and replace the travertine...but I would appreciate any thoughts on the cause of this issue and how to properly fix it.

Pool and the surrounding concrete base were finished in late May 2021. Travertine was completed in mid-July 2021. We noticed the water feature starting to sink/crack in March of 2022 and it has progressively gotten worse. The surrounding coping is also sinking--several pieces are cracked and sound hollow underneath when you knock on them.

PB said the salt water blow-back from the feature is the culprit...plus the lack of proper sealant? Not sure what to think. Happy to answer any questions or provide additional photos.

 

[jesse-99]

I'm not even sure what a travertine really is, so hard to comment on that.. I have heard from numerous builders and pool professionals that if there's going to be failures like you see, it's common to see it in the first year, or maybe two... if you can make it past that first year or two, any shifting that might have occurred, or any structural issues, would likely have happened already and aren't like to occur. I've asked this repeatedly because I have about 50 tons of boulders over a water slide and cave grotto and constantly worry about those boulders coming down and collapsing, but everyone reassures me that, 11 years after the build, it's not going -anywhere-.. and I also got confirmation from 3rd parties that we there during construction that the builder doubled all the rebar and other support structures that are needed.

So I don't think I'm much help to you, but I'm curious if they're willing to fix/repair/replace under warranty for you? I'm not sure what salt water would have to do with anything. Did they say whey they felt the salt might have contributed to things, especially if CSI was in balance, etc. ? Is the whole pool area brand new construction? New patio/decking, etc.? I guess there could have been a lot of shifting over the last year, are you in cold weather climates for winter?

 

[needsajet]

Wow, that's a bummer. My first thought was poor compaction under the deck surrounds, but it looks so even along the edge that I started to wonder if the pool is rising. Have you had a lot of rain or saturated soils since the build? Any plumbing issues such as leaking from cracked pipes? Does the pool have a hydrostatic valve?

With a lying pool builder, you kinda have two options. Patch as best you can, and there are people around who could make the problems disappear aesthetically, but likely only temporary. If you wait a couple years, it becomes a bit less likely to be temporary, but you'd still have the lip at the edge of the coping. The other is to hire expertise and put together a lawsuit for poor workmanship, but that one really depends on whether the PB has coverage or is stable, wealthy enough to pay, etc.

But no, "saltwater blowback" (whatever that is) doesn't make concrete monoliths move, and all pool water is salty, regardless of chlorination method. Sealant holding concrete in place? That's even more ridiculous.

 

[Tcadwall0]

It doesn't have anything to do with salt.

Was it a very rainy time when the pool was being built? I agree with the compacting idea.... but I know that my pool was installed during one of the most rainy seasons we have had in decades. I have a lot of slight settling of my travertine. I watched it being prepped and installed, and it was done very well.... but.... the soil was completely saturated when it was done and I have had up to 1/4 inch of settling on my travertine. The coping stayed in place but that is because of the bonding concrete that it is mounted on, and the clean gravel that is under the concrete against the pool.

The PB has stated several times that he is scheduling his travertine crew to come back out and fix the settled tiles (yet they haven't showed), but I am not stressing over it, because I know that it is a simple fix when I get around to it if he doesn't. I don't blame him or the crew. The ground was saturated, it was going to settle. 1.5 years later.... yeah, there are a couple dozen tiles that need to be lifted and re-sanded.

That said, you have a water feature, that should have been fully supported by concrete. It should not have been set over half-concrete, half-compacted base material. My opinion is that is what happened. It needs to be pulled up, and a better foundation poured for it.

My 2 cents.

 

[AQUA~HOLICS]

Is the water feature on a footing?

 

[ts2018]

Is the water feature on a footing?

Not sure what you mean. It has (or at least had) a concrete base. I am not sure if the travertine was laid under it, but I can find out.

 

[ts2018]

Wow, that's a bummer. My first thought was poor compaction under the deck surrounds, but it looks so even along the edge that I started to wonder if the pool is rising. Have you had a lot of rain or saturated soils since the build? Any plumbing issues such as leaking from cracked pipes? Does the pool have a hydrostatic valve?

With a lying pool builder, you kinda have two options. Patch as best you can, and there are people around who could make the problems disappear aesthetically, but likely only temporary. If you wait a couple years, it becomes a bit less likely to be temporary, but you'd still have the lip at the edge of the coping. The other is to hire expertise and put together a lawsuit for poor workmanship, but that one really depends on whether the PB has coverage or is stable, wealthy enough to pay, etc.

But no, "saltwater blowback" (whatever that is) doesn't make concrete monoliths move, and all pool water is salty, regardless of chlorination method. Sealant holding concrete in place? That's even more ridiculous.

Thanks for the response! We've had a fair amount of rain this summer--but it was months after the cracking/sinking started. I do not believe we have a hydrostatic valve, but I can find out. And no other plumbing or leaking issues that we've been able to identify. That was our first suspicion.

Our current PB has agreed to remove and replace all of the travertine on his dime...but we are obviously pretty weary of his contractors' work product. Currently trying to gather some experts to get a better understanding of exactly how this material should be installed (base/grout/sealant, etc.) and maintained.

 

[AQUA~HOLICS]

Your deck is settling due to improper compaction. The product could have been installed properly but on top of a poorly installed base.

 

[ts2018]

It doesn't have anything to do with salt.

Was it a very rainy time when the pool was being built? I agree with the compacting idea.... but I know that my pool was installed during one of the most rainy seasons we have had in decades. I have a lot of slight settling of my travertine. I watched it being prepped and installed, and it was done very well.... but.... the soil was completely saturated when it was done and I have had up to 1/4 inch of settling on my travertine. The coping stayed in place but that is because of the bonding concrete that it is mounted on, and the clean gravel that is under the concrete against the pool.

The PB has stated several times that he is scheduling his travertine crew to come back out and fix the settled tiles (yet they haven't showed), but I am not stressing over it, because I know that it is a simple fix when I get around to it if he doesn't. I don't blame him or the crew. The ground was saturated, it was going to settle. 1.5 years later.... yeah, there are a couple dozen tiles that need to be lifted and re-sanded.

That said, you have a water feature, that should have been fully supported by concrete. It should not have been set over half-concrete, half-compacted base material. My opinion is that is what happened. It needs to be pulled up, and a better foundation poured for it.

My 2 cents.

Thanks for your response! Do you mind answering a few more questions about your travertine? Really just want to confirm your foundation materials. Also is yours grouted?

 

[Mcow]

From your pics it looks like the travertine was set over a concrete deck is that correct? If so do you have any pics from right before they pored the concrete? What did the rebar look like? It looks like the concrete underneath has sunk possibly due to improper site prep. Often times you need piers poured under the concrete decking in poor soil conditions (high clay content). You may need to have the concrete lifted there are companies that can do this with foam. They drill a small hole in the concrete and inject an expanding foam that lifts the concrete to level. Alternatively they can just remove and relay the travertine adding more sand to try to try and level it with the cooping. but that is more of a patch in my opinion compared to fixing it.

 

[ts2018]

From your pics it looks like the travertine was set over a concrete deck is that correct? If so do you have any pics from right before they pored the concrete? What did the rebar look like? It looks like the concrete underneath has sunk possibly due to improper site prep. Often times you need piers poured under the concrete decking in poor soil conditions (high clay content). You may need to have the concrete lifted there are companies that can do this with foam. They drill a small hole in the concrete and inject an expanding foam that lifts the concrete to level. Alternatively they can just remove and relay the travertine adding more sand to try to try and level it with the cooping. but that is more of a patch in my opinion compared to fixing it.

Appreciate your response! Correct - there was a concrete deck poured first. I will look to see if I have any pictures right before they poured it. We have contacted a company that does the concrete/foam leveling to come take a look. Not sure exactly the extent of damage to the concrete deck though since it sounds hollow in a few places.

 

[Mcow]

Appreciate your response! Correct - there was a concrete deck poured first. I will look to see if I have any pictures right before they poured it. We have contacted a company that does the concrete/foam leveling to come take a look. Not sure exactly the extent of damage to the concrete deck though since it sounds hollow in a few places.

Do you happen to know what type of soil you have? Is it clay? We actually built a new house along with a new pool and had to do pretty extensive soil conditioning for both the house and the pool. Do you know if you have a high water table?

I believe the idea behind the foam is it will fill the voids left by expanding/contracting soil so this may be the best option but I am sure them and possible your PB can offer insight. If I had to guess your PB's plan will be to simply pull up the pavers and reset level which may or may not work long term and possibly not correcting the underlying issue.

Obviously there could be a leak or drainage issue washing away the soil from underneath. The other possibility is your pool raised and the deck stayed in place but I think it is more likely the deck is sinking. You may be able to test this out by running a long straight board across the width of the pool from an area that looks more level to the lower area resting it only on the coping then putting a level on the board to see if the coping is level on both sides.

 

[Tcadwall0]

Do you mind answering a few more questions about your travertine? Really just want to confirm your foundation materials. Also is yours grouted?

Sorry for the delay.

Ground is clay around here.
When they did our decking, they waited for it to be dry... but that simply meant no standing water.
Under and around the FG pool is clean gravel, under the decking is a layer of abc gravel, compacted, then they used granite sand and compacted that.

I do have a sump tube near the deep end, which the concrete collar was poured around, and is covered by a travertine tile that has a finger hole in the middle so it can be lifted and I can pump water out if it builds up in the clean gravel. Only had to do that during construction.

As far as the stone, it is not grouted. Only the marble coping is grouted. They brushed in the polymeric sand after laying the travertine.

 

[JamesW]

I do have a sump tube near the deep end, which the concrete collar was poured around, and is covered by a travertine tile that has a finger hole in the middle so it can be lifted and I can pump water out if it builds up in the clean gravel.

How much water in the tube right now?

A settling deck is probably an insufficient compaction issue.

 

[Mcow]

Sorry for the delay.

Ground is clay around here.
When they did our decking, they waited for it to be dry... but that simply meant no standing water.
Under and around the FG pool is clean gravel, under the decking is a layer of abc gravel, compacted, then they used granite sand and compacted that.

I do have a sump tube near the deep end, which the concrete collar was poured around, and is covered by a travertine tile that has a finger hole in the middle so it can be lifted and I can pump water out if it builds up in the clean gravel. Only had to do that during construction.

As far as the stone, it is not grouted. Only the marble coping is grouted. They brushed in the polymeric sand after laying the travertine.

Ok this is what I suspected. So more than likely what has happened is when the deck was done in the Spring the clay was moist holding a lot of water. During the summer the soil drys and looses it's water retention (not sure about you but here in Texas we had an extremely hot and dry summer). So essentially you are going to have some upward and downward movement depending on the season. It could be compaction too but I think it is more due to the ground movement from the expansive clay soil. We have the same type of soil and had to do chemical injections to stabilize it for our house and pool. The benefit to not putting the pavers on a concrete deck is the rise and fall may be more isolated to a few pavers instead of a larger section of the concrete so easier to fix. We actually have a few paver that have sunk in this way that are getting fixed soon but it is isolated to just a few. I would look into the foam injection raising of the slab underneath we already discussed. I do not know a ton about this but know people who have had it done with success at least initially.

 

[Tcadwall0]

Hey guys - for clarity I am not the OP. The OP had asked how my travertine was done. I do have a couple dozen that have slightly settled, but not structural issues like what was posted.

But to answer the question anyway...

How much water in the tube right now?

It is dry. Tons of rain in the last week (had to pump water out of the pool twice) but nothing in the sump.

 

[Mcow]

@Tcadwall0 Sorry just realized I replied to you and not the OP!