New Pool Construction - Concrete Cracking

[VFMA1991]

Hello Everyone!
I am a first time pool owner. We are having a pool built in PA by a local builder. The shell in now in but have a problem. I am seeing cracks in the base of the pool. I was told they are surface cracks and not going through. So, my questions are.

Is this normal as the pool guys say?

They are telling me that the cracks are not all the way. However in the picture I can see water coming through, but told that is just the water from me watering down the pool. I do not buy that as we are on a high water table.

We are doing a plaster finish.

I am told I am worrying about nothing however, just not so sure. Any insight I would be happy to hear! Thanks!

 

[pooldv]

Yep, perfectly normal. Most people building a pool experience this and ask the same question.

 

[gwegan]

Well I'm not going to say ok wonderful, but the bottom line is many gunite and shotcrete shells have cracks. If all the crews worked perfectly on days with the correct humidity, temperature, water and material mixture there would be no cracks. But cracks happen. When they plaster the pool the plaster will to an extent fill the cracks and seal the pool and you will end up with a giant concrete bathtub that acts as a single structure.

We could go over the things that can go wrong but cracking is not necessarily a sign of poor workmanship. Where are the cracks? On the floor or low down on the walls? In the seats or steps? If that's true, it could be a rebound problem. But that's not what I'm seeing on your pictures.

 

[philboyj]

Even without the cracks, the concrete shell is considered to be a "porous" structure. The inside plaster is what makes the pool watertight. So, whether the water is trying to come in from the high water table or from the sides by watering, that does not matter.

Did the contractor leave "weep" holes at the bottom of the pool? My shell had 6 of these holes and they were spread around the pool bottom - this for for relieving the upward pressure that a high water table or ground movement might exert onto the empty pool shell. These holes are filled at the time of plaster. Once water is filled into the pool ( generally within 24 hours after plastering), the weight of water balances any upward pressure.

But you are on the right track - ask questions till you are satisfied. Let the PB know that you are watching, but at the same time you have to trust the PB - it is a fine line balancing act.

 

[VFMA1991]

The cracks are on the floor. Not problems on the walls.

- - - Updated - - -

Thanks. The know I have been watching. lol They are sure they will not be a problem. Getting a lot of money into the pool. Thanks for your feed back!