Wacky question...Pool and Concrete/Foundation experts

[Damian Sanders]

What if you wanted to build a massive outdoor pool that could later be used as a home foundation? Yes, I'm serious.

Something like 40x70 feet. 12 ft deep end. Built to withstand damn near anything, near a wetlands area/stream that could rise eventually and turn into a small river. Not an overly complex construction, just durable, large and well anchored. No heat on the pool and probably use heavy duty old school used pool gear. It would have to last for 20 years as a pool and then still be suitable to be used as a foundation for another 200+. It would probably cost an arm and a leg in materials.

Thoughts?

[bean]

Caltite concrete addmix - makes the concrete waterproof. Perfect for use as a pool to keep water in then as a basement foundation to keep water out. 8" wall with (2) #5 rebars at 16"oc should do it. Use some heavy 4x4" mesh in the slab.

Don't forget the caissons.

[nhtele]

Yeah, you're gonna definitely want to include buoyant forces due to shallow groundwater when you do the design. I'd be rather surprised if the soils so close to a wetland would support the anticipated loads, regardless of footer width so deep foundation would likely be needed. Helical piers are a nice choice because they are self-testing during installation and theoretically have the same strength in both compression and tension.

Sounds like an interesting project.

[Damian Sanders]

Awesome.....can you guys suggest some resources to research the design of something like this? This is still purely a theoretical of course....thanks!!!

[Shredhead]

I have a 9' deep pool in a high water table area. There is a valve in the bottom that allows water into the pool to keep the static pressure from popping the entire pool out of the ground. My pool never has less than 4' of water in it.
I think you could probably do it, but it would make a shitty basement. You would need to put in a really good drain system with sumps before hand.

[Core Shot]

Don't feed the trolls.

[Damian Sanders]

Don't feed the trolls.

It's a serious question.

Really. Just something I'm considering doing, and I'm trying to figure out how realistic or unrealistic it is. Just looking for initial guidance here.

Everyone else:

Any guesses on how much something like would cost? 40x70 ft. Waaay overbuilt.

- Completely contracted out

VS.

- Much of the engineering, digging, and rebar/form fabrication done myself. Have to pay for the concrete, steel, wood, gravel, etc. The engineering work would be reviewed by a certified P.E. (professional engineer) before starting construction.

Thanks!!!

[DJSapp]

Absolutely possible. Get a geotechnical report and an engineer to design it. You'll be out at least $4 MM all said and done.

Signed,

A contractor who builds water treatment plants that do exactly this.

edit: I highly doubt you'll do any of the work by yourself. Completely serious. You have no idea what you are starting.

[Damian Sanders]

Absolutely possible. Get a geotechnical report and an engineer to design it. You'll be out at least $4 MM all said and done.

Signed,

A contractor who builds water treatment plants that do exactly this.

edit: I highly doubt you'll do any of the work by yourself. Completely serious. You have no idea what you are starting.

Thanks man.....water treatment plants, huh? Sound like a good place to look.

I'm a mechE, btw. I'm a little rusty, but I would enjoy designing something like this, and would probably learn alot in the process about construction, realestate development, etc. I'm also mechcanically inclined and like learning new things in that regard. I also have somewhat of a knack for doing things cheaply.

You are right, at this point I have no idea...it's probably way too much work for one person, or even a small crew. Thanks for the warning, it is well taken.

[DJSapp]

Rough #'s

excavation & export of dirt--1700 cy minimum. depends on soil
piles--depends on conditions
concrete--assuming 3' walls 700 cy @ $150/cy = $105,000 in material
concrete form, pour, & strip--8 MHR/CY @ $50/hr = $280,000 in labor
rebar--assuming 20% by vol of concrete placed--1,728,720 lbs. @ $1.20/lb installed = $2.1MM
equipment to handle 250,000 gal pool $50,000 min (keep in mind a typical pool is 30-40k gal)
outside engineering $150k

Add 10% for tools and 15% profit on this and you're over $3MM without the dirt or foundation work. And forget about the permits required.

[Rideski]

Would you use race stock concrete?

[DJSapp]

Would you use race stock concrete?

If you can find spec. concrete for less that $150/cy in CA, please shoot me a pm. I'll make it more than worth your while.

[Damian Sanders]

Rough #'s

excavation & export of dirt--1700 cy minimum. depends on soil
piles--depends on conditions
concrete--assuming 3' walls 700 cy @ $150/cy = $105,000 in material
concrete form, pour, & strip--8 MHR/CY @ $50/hr = $280,000 in labor
rebar--assuming 20% by vol of concrete placed--1,728,720 lbs. @ $1.20/lb installed = $2.1MM
equipment to handle 250,000 gal pool $50,000 min (keep in mind a typical pool is 30-40k gal)
outside engineering $150k

Add 10% for tools and 15% profit on this and you're over $3MM without the dirt or foundation work. And forget about the permits required.

Thanks for the writeup.....what would something like that normally be used for? Sounds completely overkill for what I'm thinking of though.

My budget would be around $50k.....what can I get for that? Nothing?

[DJSapp]

Hell, I think 50k is about right for a regular in ground pool these days. Nevermind about your uber-pool. The whole world changes once you say that you want to build on top of it.

And those dimensions came from a waste water treatment plant that I just estimated last month.

[DJSapp]

Hell, I think 50k is about right for a regular in ground pool these days. Nevermind about your uber-pool. The whole world changes once you say that you want to build on top of it.

And those dimensions came from a waste water treatment plant that I just estimated last month.

[Below Zero]

This idea is uneconomical. Your walls will need to be designed just like a basement foundation. To span 40'-0" with first floor framing members is uneconomical. Will you be designing column foundations in the middle of the "pool" for added columns at a later date?