crack in concrete & trim

cybernation

Well-known member
May 8, 2011
50
Orillia, ontario, canada
Hello all,

Here is a weird issue with the pool, and i'm not sure if i have to be worried about it or not. On one of the corners of my vinyl pool is/was getting pushed/caving in due to rain washing away the soil. I really don't describe things well so here are some pics below.

When your in the pool on at that corner, you can feel a 1/2 - 1" lip in the side. I'm sure i won't be able to fix this without spending a fortune (i have a leaking house not from pool), but should i be worried?

Thoughts?

Another thought i had was putting silicone in the concrete cracks all along the pool to make it look better, and keep the water away from the concrete.. Any reason not to do this?








I was thinking of putting some soil/clay/rocks here to help with the slope so it won't make the concrete slab move below:



 

PoolGuyNJ

TFP Expert
May 20, 2007
3,192
South Central NJ
That looks like it heaved, either from ice or swelled clay.

Self leveling caulk is a good idea.

Was there any gravel under the slab before they poured it or was it poured on the dirt?

Scott
 

cybernation

Well-known member
May 8, 2011
50
Orillia, ontario, canada
Re: crack in concrete & trim

Hello all,

Well one year later and I still haven't fixed the gap.

I'm not sure if I should try mud jacking or slab jacking.

Is it possible for a diyer to fix the concrete? Should I chip up the whole section and lay more concrete down by hand?

Has anybody else had a similar issue with loose coping and heaving concrete ?
 

PoolGuyNJ

TFP Expert
May 20, 2007
3,192
South Central NJ
From the pix, I would say its likely that the entire section of concrete needs to be removed. Leave any rebar in place. Realign the coping and repour the section with gravel under it. It won't be an exact match for color but...

Scott
 

PoolGuyNJ

TFP Expert
May 20, 2007
3,192
South Central NJ
I'd lower it a little but even with plastic sheeting on the pool surface, some concrete is bound to get in the pool during the demo.

If your Fall is rainier, I'd do it now.

As for cost, I have no way of knowing. You have a different market.

Scott
 

cybernation

Well-known member
May 8, 2011
50
Orillia, ontario, canada
I got a quote
4600 for replacement of whole deck.

My question is should I try to put paving/interlocking stone in place of the concrete? I could manage to do that was a DIY. I do have a couple of herniated discs in my back :cry:
what would I do for the coping if I did interlocking stone?

Is it wise idea in a cold & snowy climate? I'm in Canada.

Thanks again!
 

PoolGuyNJ

TFP Expert
May 20, 2007
3,192
South Central NJ
That depends on the drainage of the soil and the height of the water table. My concern is frost heaves. Your frost line is pretty deep. Water trapped there will freeze and thaw. This is the cycle that causes it.

Scott
 

dayhiker

LifeTime Supporter
Jun 6, 2008
304
Pell City, AL
cybernation said:
Hello all,

Well one year later and I still haven't fixed the gap.

I'm not sure if I should try mud jacking or slab jacking.

Is it possible for a diyer to fix the concrete? Should I chip up the whole section and lay more concrete down by hand?

Has anybody else had a similar issue with loose coping and heaving concrete ?
From the top picture, it looks like settlement to me. The joint at the top of the photo looks clean, so those two segments are still aligned, which then makes it seem like the bottom one has dropped. What does the next adjacent joint look like? I'm a structural engineer and see poor compaction on residential projects pretty often. Heck, I see it on commercial projects behind retaining walls (which is sort of what a pool is) pretty often too. I have the exact same issue on one corner of my pool. This corner is adjacent to a slope where the back corner had to be built up when we built the house. I have put an outdoor, concrete colored caulk in the joint to at least keep water out. I'm in AL, so frost heaving isn't that big of a deal here. I didn't see your location in your profile, but like the guy from NJ says, if you're up north, it's obviously a big deal there. Slab jacking for something that small is likely not worth it. That's generally better done on bigger areas. It also means 2" diameter holes get drilled for the grout access. For exposed concrete, this becomes an eyesore. I'd either caulk to protect water intrusion and leave it be or remove and replace. I've left mine be for the time being. It's almost enough to be a trip hazard, but has stopped moving. If it continues, I'll have to remove and replace. If the movement does ebb and flow over time, it can indicate a different issue. If it shrinks during drought and grows during rain, that would indicate plastic clay, which is nasty stuff. Are you seeing any type of seasonal movement?
 

cybernation

Well-known member
May 8, 2011
50
Orillia, ontario, canada
The side that is beside it on the slope ground is doing exactly the same thing but not as bad yet. I'm sure it's only a matter of time.

Another issue is on the same side of the pic, the pool shell is coming up in the water. Again it was like that last year but I think it's a little worse now. We've had a really dry summer. So I'm not sure how/if it got worse.

I got a quote to fix it, and he didn't mention anything about the subbase. He did say he would put in an a-frame so the concrete won't sink again.

I've lived in this house for one year, and the side in te picture was like that last year

I'm in Canada and we get a lot of snow here.

Apparently my yard was built over a swamp 20some years ago and I'm having water problems in my basement. It's not near the pool. I think the drainage of the whole property stinks.
What are your thoughts?
 

dayhiker

LifeTime Supporter
Jun 6, 2008
304
Pell City, AL
cybernation said:
The side that is beside it on the slope ground is doing exactly the same thing but not as bad yet. I'm sure it's only a matter of time.

Another issue is on the same side of the pic, the pool shell is coming up in the water. Again it was like that last year but I think it's a little worse now. We've had a really dry summer. So I'm not sure how/if it got worse.

I got a quote to fix it, and he didn't mention anything about the subbase. He did say he would put in an a-frame so the concrete won't sink again.

I've lived in this house for one year, and the side in te picture was like that last year

I'm in Canada and we get a lot of snow here.

Apparently my yard was built over a swamp 20some years ago and I'm having water problems in my basement. It's not near the pool. I think the drainage of the whole property stinks.
What are your thoughts?
A few macro type photos might help. A big picture often helps put the pieces into context a bit better.

As far as the basement goes, sounds like they didn't use a free flowing backfill material and didn't adequately waterproof the outside of the walls.
 

dayhiker

LifeTime Supporter
Jun 6, 2008
304
Pell City, AL
It looks like the two corner pieces are heaving up and then pulling away from the pool. Is that correct? I think that's somehow a temperature of freezing issue. The thing is, the concrete shrinks when it gets cold. If you had an expansion issue where the straight sections were expanding, they would push on the corner pieces from both directions and push them out. The problem is that, is that the volume of the concrete is generally as big as it's going to get when the it gets poured. The thermal expansion generally can't be more than that initial volume. For that to happen, you'd have to have temperatures much higher than you can actually have. I have heard of it happening in very long runs of paving followed by a curve where the concrete paving didn't have control joints. That's not your situation. The heaving sure seems to be winter freezing.

I'd ask what the heck an a-frame is. I'm not familiar with what that means.

When I've done buildings in the north, the outside walks and entries will have turn down edges that go below the frost line. It's been a while, but I think you also put something under the slab to somewhat absorb or account for the heaving. It would seem that on the pool side edge of the pool that you can't really have that turn down to get below frost depth. I'm sure there's a local way that the installers deal with that. Maybe the pool guy from NJ that previously commented could shed some light on that point.
 

cybernation

Well-known member
May 8, 2011
50
Orillia, ontario, canada
Few years later and I haven't got off my butt to fix. Now I need to since the crack is moving along the bottom, at the stairs and by the fence and the steel wall piece appears to be sinking in the corner.

I have requested a few quotes and they are in my opinion really high. I had one with replace pool deck with interlocking stone total cost $9,000 CAD. He would remove deck, put back interlocking stone. 314 sq to be exact, nothing else.
I didn't feel comfortable with the quote cause he didn't say he would do a retaining wall or replace the liner. I asked him to include retaining wall. Quote turned out to be $16,000. This retaining wall would be 2-3 ft high. Liner or smoothing of pool floor is not included in this price.

Another quote is about 17,800k
$3200 liner
$1700 cut out cracked section of floor and re-coat
$350 line tests
$2200 removal of deck + excavate for retaining wall
$4500 for concrete deck (350 sq)
$5850 for retaining wall around pool to hold dirt from moving


Question for the community. Is this a reasonable price?
Could I do the work myself and save more than half the price?
I was looking on youtube and the liner doesn't seem to be difficult and the smoothing of the concrete floor doesn't look hard, but what to I know.

I was thinking of getting a contractor and rip out all the concrete decking $2000 - 2500. I would then see what the sub base looks like, I would then add more gravel myself and let it settle over winter and in the spring, replace coping, and liner possibly get a contractor to lay the interlocking stones or do it myself. Also, fix the steel wall and perhaps pull it up?
Does anybody know if I can rip the concrete out with a pool full of water? Can I drain the pool to rip out the liner afterwards?

I would also do a retaining wall myself if needed. I cannot get an exact answer from the pool reno guys of why the pool deck sank this much over a 3 year period.

pics are here:
https://plus.google.com/photos/109780496801373746753/albums/5779303275435093377?banner=pwa
 

wrangler1217

Well-known member
Jul 2, 2012
49
Central MS
I'm having the exact same problem with the shifting decking. I've been in the house 2.5 years now, and the pool is 10 years old. Last year, it was barely noticeable - just appeared to be some surface cracks/settling of the concrete. But this Spring, there's about a 1.5" gap that opened up from one of the cracks. There's been either one or two things that's caused mine to do this:
- At the far end of the pool (where the cracking is), the neighborhood association (in all their infinite wisdom) decided to plant 5 Bradford Pear trees to align the entrance of the neighborhood. These trees are approximately 20 years old, and literally "suck" all the moisture from the ground in-between the far end of the pool, and the trees themselves, thus leaving the ground bone dry - contracting that end of the pool towards the trees.
- The roots of the Bradford trees are out of control, climbing under the pool decking and uprooting it. I chopped them up as best I could...hoping that whatever's left up under there will rot, and everything will settle back to normal. The funny thing is, the roots of the trees were no more than 1.5" thick - but they sure can move masses.

As far as doing the work yourself - keep in mind that most of this work, once it's "done", there's no going back. At least with contractors - they, for the most part, have to do the job right...or pay for it. But if you're comfortable with doing all the grunt work, by all means...go for it! But just something that involved...as a personal preference, I'd just want ONE person I could go to and say..."hey, you fixed my pool 6 months ago...and it's got a bad leak right now." That way, they couldn't blame it on something that YOU did/didn't do.

I'm definitely following this thread. Would love to know how everything turns out.
 

cybernation

Well-known member
May 8, 2011
50
Orillia, ontario, canada
See that's the funny thing, my neighbour has a pool with the same problem as mine on the corner that is beside my crappy corner.

There is a tree (giant weed) between our 2 corners. So I wonder if that's adding to the problem/cause of the problem.


Another thing to add, I think they neighbourhood swale is where the fence is. I do not know if this washes away soil.

One of the contractors said I should just fill it. He also said he would only offer 2 year warranty, since he does tl know the reason why this happened.




Sent from my iPhone using Tapatalk
 

cybernation

Well-known member
May 8, 2011
50
Orillia, ontario, canada
Here's a pic of my pool and the neighbors. The tree is in the middle. I though the tree might be causing some issues, but i'm seeing some movement on the other corner of the pool. Funny that the neighbor's pool is doing exactly the same thing as mine.