Concrete slabs sinking around pool. What could be done?

[jeanft]

Hello,
Trying to figure out the best options to replace concrete slabs sinking around pool.
Rain water ending up in back of pool area, decay of roots from removed trees? Slowly going down through years.
The issue with concrete upfront was caused by water leak a few months ago, elbow broken for pipe going back to pump.
A few ideas so far:
- Remove old concrete and install new one with steel bars. Some indicated that it would be better to add dirt and compact it and see what happens for a few months before pouring new concrete. Now no bars in it.
- Adding river stones on top seems really pricey considering sq ft.
- Pour concrete on top of actual slabs and bring up to level. Don't see how adding more weight would stop the problem.
- Drill holes in slabs and inject material to bring them up.
- Resurface all area by removing rocks on top and apply special coat of rubber paint.
Trying to limit cost since planning to move out soon.

 

[cowboycasey]

Your problem is they used the dirt that came out of the pool for backfill and it has settled over the years... Now that it is compacted do not disturb the dirt... break out the old concrete and remove.. using #57 clean rock bring the area up to level and pour new pad around pool...

Gravel Around Pools - Further Reading

www.troublefreepool.com

 

[JamesW]

In my opinion, the pool floated up some.

Do you have any cracks in the shell?

How much has the pool floated from the original level?

Is the pool out of level now?

You probably need to pressure test all lines.

For the deck, you would probably need to do a deck at normal slope and then do a step at the edge of the deck since it would be higher than the yard.

 

[JamesW]

When was the pool originally installed?

Do you have pictures of the original installation?

 

[sktn77a]

Are there any cracks in the shell? What's that white stuff between the tile and the plaster? If you're happy with the existing decking, and the shell isn't cracked, I'd drill the holes and mudjack it up level. Judging by the angle of the decking, it looks like the decking sunk rather than the pool lifted(?)

 

[JamesW]

They are doing a replaster.

The contractor chipped under the tile and around the fittings.

They also cut out some hollow spots in the plaster.

Then, a gray bondkote primer was applied over the existing plaster.

The white you see is original plaster.

In my opinion it looks like the pool floated and shifted and the deck probably sank down some.

If you lifted the deck up to the level of the coping and put a normal slope on it, it looks like it would be higher than the surrounding yard, which points to some float, in my opinion.

I would want to verify if the tile is perfectly level before proceeding with the replaster.

Check the level of the tile with a transit.

 

[JamesW]

You can see a substantial crack in this picture.

 

[jeanft]

Thank you for your answers. There is a slight lift in the coping around steps. I still wonder if removing two oak trees and a pine many years ago did not create this problem. I think the issue is more related to the ground, have a long crack running in the garage concrete as well. They found a small line running along bottom of pool, other thing could be water running out from light, useless for years.
They are coming tomorrow to plaster the pool, will mention the pressure test.

 

[JamesW]

Realistically, I think that to really do everything right, you would need to remove and replace the coping, tile, plaster and decking.

If the skimmers are bad, they should be replaced. I would want 2 new good skimmers.

The return plumbing should probably also be replaced.

If there is a main drain, I would plaster over it and do without it.

 

[JamesW]

Before draining, was the water level perfectly level hitting the exact same spot on the tile everywhere?

 

[JamesW]

I'm guessing that the pool is over 40 years old, right?

 

[jeanft]

Right. The house was built in 76. The tiles look a bit higher on the right side close to the steps where the coping lifted. As long as there are no leaks, I don't plan to spend $20.000 at least to redo it all. We are planning to sell the house. Thank you for your help.

 

[JamesW]

Ok, hopefully, it will turn out well.

 

[JamesW]

How much water were you losing per day?

 

[cowboycasey]

James, I never even thought about it floating... Great catch

 

[jeanft]

Hello James,
The pool lost water when this elbow ended up with a crack in it, pipe going from skimmer close to steps back to pump. Both PVC tubes were not at the same level when they built the pool and certainly created stress on the part. Crazy that there was not any issue earlier. This water running underground created the movement of concrete slabs in the area. Water loss was not too alarming since it was end of summer and there was not a lot of rain. The pump has been turned off since November.
I think it's a good idea to plaster the main drain, I never used it. I just learned that you had to shut off both skimmers to use it!

 

[JamesW]

Ok. Thanks for the update.

Hopefully, everything will work out well.