Volcano in my Pool...

[RASelkirk]

Hi All,

We recently had our deck refinished and it rained directly after the concrete dye was applied causing the dye to run into and stain our pool. The guys just came back with the intent to paint the waterline area, so I drained about 2 ft for them to be able to work. The stains came up w/o the need for paint, but while they were in it cleaning, they found a "volcano" in the deep end where the transition slope meets the floor. It's pressed up from the bottom about 1" tall with 3 major breaklines about 18" across. Not losing water yet, but I'm sure that will happen soon. My pool builder thinks my draining 2 ft could have done it, I'm not so sure it isn't a root from the large tree that's 20 ft from the coping off the deep end. He thinks 8 ft is too deep for a root and the ground water "push" has done this. Either way, it's gonna cost big $$$ to fix. If it is a root, how can I ensure that the offender is permanently capped and won't regrow?

Russ

 

[jblizzle]

I might could be due to ground water, but I would not think that draining 2 feet would have caused that isolated problem.
Did it just suddenly appear?

 

[RASelkirk]

I might could be due to ground water, but I would not think that draining 2 feet would have caused that isolated problem.
Did it just suddenly appear?

As far as I know, it's new. This time of year I'm in swimming 3 or 4 times a week, and even with the Barracuda, still need to pick stuff off the bottom. I saw that, thought it was a twig, swam down to grab it, and almost sliced through a couple fingers. The edges are quite sharp!

It prolly wasn't even 2 ft. I'll go measure for sure, but just to the bottom of the two little seating areas. My pool guy says they wouldn't consider draining anything with all the rain we've had. Not so bad here, but he's 100 miles West of us in Houston. I'll try and get with my landscaper and ask about the possibility of it being tree roots at that depth...

Russ

 

[bmoreswim]

Given that your location is probably sea level plus a couple, I could see your pool having raised ever so slightly while drained and then when re-filled it teetered, then cracked on a big object/rock under the shell. It does seem kind out counter-intuitive that a root would go that deep into soil that likely has a regularly high water table. I take it there is no well-point or unknown round cap at ground level near the pool?

Having appeared at the same time seems like quite a coincidence to not be related.

 

[JamesW]

It looks like typical plaster delamination.

It's not going to be from a root. A root isn't going to penetrate through 9" of gunite.

It's probably not related to lowering the water level. Lowering the water level can cause the deep end to rise and crack along the transition line from shallow to deep, but the deep end would have risen and you would have a long crack.

The plaster is about 3/8" thick. Most likely, a bubble formed where the plaster delaminated and finally burst.

To fix, you would need to cut out the delaminated spots and patch.

 

[RASelkirk]

It looks like typical plaster delamination.

It's not going to be from a root. A root isn't going to penetrate through 9" of gunite.

It's probably not related to lowering the water level. Lowering the water level can cause the deep end to rise and crack along the transition line from shallow to deep, but the deep end would have risen and you would have a long crack.

The plaster is about 3/8" thick. Most likely, a bubble formed where the plaster delaminated and finally burst.

To fix, you would need to cut out the delaminated spots and patch.

My sig must not be showing on your device. My pool is fiberglass.

Given that your location is probably sea level plus a couple, I could see your pool having raised ever so slightly while drained and then when re-filled it teetered, then cracked on a big object/rock under the shell. It does seem kind out counter-intuitive that a root would go that deep into soil that likely has a regularly high water table. I take it there is no well-point or unknown round cap at ground level near the pool?

Having appeared at the same time seems like quite a coincidence to not be related.

The pool is close to 25 years old. I was here when they did it and the underlayment was all sand fill over native clay. Of course, that tree was less than half it's current size too. My "tree guy" is on vacation and he doesn't remember the tree so I'll text him a pic later...

Russ

 

[JamesW]

Ok, it looks like plaster.

I would suspect that the acrylic layer had delaminated from the fiberglass shell.

You're going to have to cut out the delaminated acrylic and see if the fiberglass shell is cracked.

Then, patch the acrylic.

 

[RASelkirk]

Tree guy says roots from the tree could be that deep. From the way it's bulged up, that's my guess. Once it's drained, I'll know for sure. Pool guy gave a quote of $4300 just to fix the floor and another $5600 to do the gelcoat/paint, but I was expecting it to be around that. There are some surface areas that have small "pock" marks that will also be covered in the overall gelcoat so I'm going with that. Last gelcoat was 2006. I'm on the list...

Russ

 

[RASelkirk]

Update: After waiting 7 months, work has finally begun. There was no "root" impingement, just damage from ground water washing out the back-fill. Areas behind the walls in the shallow end have hollowed out as most of the fill has gravitated down into the deep end causing the bulge in the floor. The crew cut out a 4 foot x 3 foot section, braced it with lumber, reinstalled the floor and put on 2 coats of Fibexx resin/paint. Supposed to be good to fill Monday.

Seems like a "half" fix as the shallow-end fill is still missing (they said they could redo the fill, but required jack-hammering our new deck), just hope it lasts until we're out of the picture...

Russ