Bad to leave gunite drained over the winter?

[PoolGuyAK]

Hey everyone!

we are having our pool replastered and having new tile and coping installed. Our contractor offered to start in the fall and finish in the spring. However they would need to drain the pool to start. I’ve heard it can be very bad to leave my pool (which is probably 30 years old at least) to sit without water.
Anyone have any thoughts/insights? I’d hate to have to empty and fill it twice.

 

[ajw22]

I’ve heard it can be very bad to leave my pool (which is probably 30 years old at least) to sit without water.

And what exactly have you heard can happen to it? If we don't care about the plaster it is just a slab of concrete sitting outside. Look at all the other concrete that sits outside through winters.

Your pool needs to have shydrostatic relief holes so ground water does not pop it out of the ground. If the contractor knows how to properly safe an empty pool and then clean it out in the spring it should be fine sitting empty over the winter.

 

[KCNM]

I have a feeling that there have been plenty of people sitting with gunite holes in the ground for 6+ months during this past year.

 

[PoolGuyAK]

And what exactly have you heard can happen to it? If we don't care about the plaster it is just a slab of concrete sitting outside. Look at all the other concrete that sits outside through winters.

Your pool needs to have shydrostatic relief holes so ground water does not pop it out of the ground. If the contractor knows how to properly safe an empty pool and then clean it out in the spring it should be fine sitting empty over the winter.

Yeah that was the concern I heard. Popping out of the ground literally! The pool company I use for opening and closing were the ones who told me to be careful. I’ll look into whether it has said hydrostatic relief holes. Good tip!

 

[ajw22]

Yeah that was the concern I heard. Popping out of the ground literally!

Yeah, like this....

 

[PoolGuyAK]

Yeah, like this....

Ummmm. Wow. How long was it empty for? This is making me nervous!

 

[newdude]

Ummmm. Wow. How long was it empty for?

Exactly one minute too long.

That’s the *female dog* of leaving it for an extended time. If the ground water is low you can easily make it a weekend. Some big spring rains / Tropical storms / etc can change the equation very quickly.

 

[ajw22]

Ummmm. Wow. How long was it empty for? This is making me nervous!

Oh, I can find other pics. Happens a lot in Florida.

You need to have open drain holes in the bottom of the pool if it will be sitting empty. If you don't have drain holes then some need to be drilled and then filled with hydraulic cement right before plaster.

 

[KCNM]

Oh, I can find other pics. Happens a lot in Florida.

You need to have open drain holes in the bottom of the pool if it will be sitting empty. If you don't have drain holes then some need to be drilled and then filled with hydraulic cement right before plaster.

Exactly this. If it's empty, it needs to be open to the ground water. That's what prevents this from happening. Otherwise, what you have is a bunch of empty air sitting below the water level. We normally call that a boat.

For my pool, immediately after draining, they pulled the plug in the main drain and then also drilled a few more holes. Water was literally gushing out of the drilled holes. It was basically a spring. The water level would go up or down with the rain, but it was always at least a foot or two at the bottom. That doesn't seem like much, but that's a lot of buoyancy force that's being negated.