Need a Structural Engineer - Concrete Wall

[Brad_Blazer]

How about a 52" above ground pool with the bottom dug out another foot?

 

[Pooh_Bear]

I'm not totally against a regular above ground pool,
I just have a plan based around having a concrete pool.
I intend to eventually enclose it as an indoor pool.
Sort of a sunroom off the back of the house.
And then build a deck on one side facing the tree line.
Under the deck would be just enough room to park my boat trailer.

Of course this won't all happen at once, but rather in stages.
So I have plenty of time to plan it all out.

Pooh Bear

 

[flusher]

I want to build an above ground square concrete tank.
24 feet x 24 feet filled with water 5 feet deep.
I want to pour a slab and build walls on the slab.
How thick should the slab be. And what about reinforcement.
I realize that I would probably be better off to erect
forms and pour the walls as a monolithic casting.
But I have a different idea for the walls.
Concrete block walls using 8 inch block to form the interior wall.
Then another exterior wall with a space between the two walls.
The blocks would be filled with concrete and the space
would also be filled with concrete. All pinned to the slab.
How wide should the space between the walls be.

I saw this same design in a book about 30 years ago.
It was for an inground swimming pool.
And the space between walls was 4 inches.
But I want to build it above ground.
And I need to know how thick the space should be.

I can't seem to find an above ground pool
that is at least 5 feet deep. So I will build one.

Thanks for any and all advice.
You're also welcome to tell me I have fluff for brains.
But I already know that part.

Pooh Bear

I went through a similar trade study last year when I decided to build an above-ground koi tank (4' x 8' x 4' deep). Checked out the concrete option and the concrete block alternative. Too much heavy lifting for an old man like me and sealing these kinds of water tanks can be a problem.

I finally decided to pour a 4-inch thick concrete slab and build the tank out of 2x8s and 1-inch plywood. Bought one of those Firestone EPDM rubber liners like folks use for landscape ponds. For me framing is a lot easier and more enjoyable than concrete or masonry work.

 

[Red55]

Flusher- nice job

Pooh Bear-
When you mentioned about turning it into an inside pool I remembered what a neighbor did- they bought a fiberglass pool. Which if I remember correctly (according to manufacturers) doesn't "really" need any structural support. Only limitation is width and distance from plant. Another neighbor by my parents put in a concrete pool in the 60's and after the first winter they had to tunnel around the perimeter of the pool- frost was heaving the walls -Ed

 

[morpheus]

Pooh, I have had an indoor pool for water exercise. I had a back injury and put in a gunite pool to swim against a current. I am not exactly sure what you are planning but I will tell you of somethings I did right and some I did wrong. I had a 8x20 gunite pool with a wall at 4ft for a spa which was 8x4 with jets at different depths and the seat was at differnet depths. I had a spa before and this was a waste of money, because we didn't use it. The pool at one end had a jet that you swam-in-place. This was a good idea. The way this worked was the jet was powered by a 4hp pump with a 6 inch supply and 6 inch return. The jet was made by a company in Germany, Speck Pumps Get Smart Get Speck . This thing worked good but it could have been better. If you look at the jet the return is in the perimeter of the piece that is embedded in the concrete. This is to say that the jet blows and suckes the water at the same place. For the most part this works fine but occasionaly the stream you swim against would just quite due to currents that would be generated in the pool. I believe that the best way would be to return the water to the pump by imbedding return pipes covered by swimming pool drain covers in the wall opposite the jet at the bottom of the wall. I am not sure about exactally what you are going to do with the pool, but to do exercises in a pool the best way is to use an aqua-belt and do it in water that is deeper than 5 feet. I had the depth of the pool at the end with the jet at a 7foot depth. This allowed me to do exercises, wearing a floation belt and not touching the floor of the pool. I bought book about water exercises and this helped me rehab my back. If you are going to do exercises you will probably have to have it covered. Living just north of Houston,Texas, I built a building around the pool. It was 16 x28 with sliding doors in each end and windows down each side. I kept the windows closed in the winter,of course and in the summer, I opend the sliding doors and this kept the temperature comfortable. The windows let the sunshine in and it warmed the concrete around the pool. I had a solar cover on cut to the size of the pool to keep the heat and the humidity in. This actually kept the humidity down. Becareful about building the building next to the house. My building was a stand alone and the humidity was controllable. I had a full size natural gas heater and it would keep the pool at a comfortalble temperature. If I can be of help let me know. Morpheus

 

[Pooh_Bear]

The best thing I can do is get in water
about as deep as up past my shoulders
and walk back and forth one side to the other.
The water needs to be right at 5 feet deep for this.

Cooling off after a long hot day would be nice too.

I have seen small tanks made out of wood.
Lowes had them in the garden area to keep water plants in.
Some were as big as 8x8 and 2 feet deep.

My pool will be connected to the house by our back deck.
The deck will be extended to wrap around one corner.
The back of the house faces south. The new deck will face east.

Pooh Bear

 

[jgrieve]

I hope you dont mind a different idea but, Ive seen an above ground pool made from steel grain bin rings. I would think you could set concrete pads a in a circle (with a transit) , set the steel on the pads , have a sand floor , and purchase a pool liner and be swimming instead of sweating in the sun. I used to have a commercial above ground pool and it was constructed in much the same way.

 

[MossRoad]

You can get custom made vinyl liners made to fit almost any size. Also, many folks dig out the bottom of their above ground pools and make them deeper. There are several companies that make deeper liners that are made just for this type of application. For what you want to do, I think it is going to cost more to do it yourself than a commercially made pool kit with everything included. Also, a permanent structure like a concrete pool may significantly increase your property taxes and insurance while an above ground pool will usually not, so don't forget to add those costs into the total price of ownership.

 

[HappyCPE]

OK, I'm not an engineer, but I do build stuff.
There are a lot of good suggestions here, but rather than do the double-wall stuff [which I don't think is needed - see the first sentence of my post, above] you could use Ivany block, which gets filled with concrete. Here's a link:
Features
It has been around a while; its use is something like the plastic foam forms that are popular today but it has a much longer track record.

 

[Nat]

Pooh, I built and installed pools for about 20 years then gave the business to my son who still does it. I guess that's my resume so I do know pools. I will try really hard to talk you out of building a pool of block and concrete. The material cost will be more that what you can buy a pool for and will be a lot more work and it will never work as good. I would find a pool dealer and explain what you want and see if he will sell you the parts. Notice I said parts, there is no such thing as a "pool kit". I always bought all the parts and most of the time I had 2 or 3 suppliers, so don't think you can pick up a box that contains a pool kit. With a steel wall and a vynil liner pool you cand have worry free skimmers and drains and returns, and an easy clean surface. Bolck and concrete are very hard to clean and a great place for algae to start growing, and it's also very hard to get a water tight joing between cement block and PVC pipe fittings. The strength of block is great when the load is straight down, but it doesn't work as well with side loads.
Then there is the cost to value side of it. No pool will add a great deal of value to a home but it will add some. That said I,ve never seen a cement block pool that didn't lower the value of a home.
I hope you take this as help from a friend, not as nit picking, cause that is the way it is meant. I have asked for your help on things to see in Chattanoga and you went out of yuor way to help and that is what I'm trying to do also.
If you want me to, Tell me exactly what you want in a PM as far as size and shape and depth, and I'll design you one, and make a parts list for you, and see if any of my old supliers will sell them directly to you and also tell you how to put it in, won't cost you a penny, but I'd think long and hard before I built one out of block and concrete. It can be done, but I've never seen it done that the owner didn't wish he had just had someone come in and build a conventional pool. HTH, later, Nat

 

[jimmysisson]

Don't forget he said he wanted to build a building on top of his walls at a later time, so the outer blocks will do double duty. I agree on keeping concrete away from where you'll touch it...
Jim

 

[Pooh_Bear]

I remember swimming in our concrete block pool when I was a kid,
and yes it could be very hard on the hands and feet.
And the algae was a constant problem to fight with.
Never could get the water to clearer than a slight green tint.

I have already asked the county tax assessor what the impact would be.
They only tax the deck around the pool. Cost would be about $60 extra.

Last time I checked I could have an above ground pool put up
for somewhere between $2500 and $3000. Complete setup but no deck.
I may go try the public pool this year and see exactly what depth I need.
To the best of my knowledge, I need a consistant depth of 5 feet.

Question about pool liners:
Can they survive being repeatly drained and refilled.

Can I even get a pool with a water depth of 5 feet. I see 52 inchers mostly.

I have a 3 feet deep by 12 feet diameter pool in storage.
I may put it up this year just to have a place to cool off after mowing.

I have plenty of time for this project. It won't all happen in one summer.
First I have to have a level spot excavated for a pool.
And I have some other excavations to be done at the same time.
Then some retainer walls to build and a driveway to gravel.
Wife says she gets her driveway before I get anything else.
So my little 3x12 pool may be all I get this year.
But then next summer I will be ready to go bigger.

Y'all have given me plenty to think about.
Thanks for all the info and advice.

Pooh Bear

 

[MossRoad]

First, let me apologize in advance for all the following quotes, but I think it easier to address question.

I have already asked the county tax assessor what the impact would be.
They only tax the deck around the pool. Cost would be about $60 extra.

Good.

Last time I checked I could have an above ground pool put up
for somewhere between $2500 and $3000.

If you want to walk back and forth a lot, maybe look into the oval pools. More walking distance.

Complete setup but no deck.

My deck cost more than my pool.

Question about pool liners:
Can they survive being repeatly drained and refilled.

Why?

Can I even get a pool with a water depth of 5 feet. I see 52 inchers mostly.

I've seen liners to 72" deep. You just install it to the depth you want and trim off the excess.

 

[Nat]

Pooh, Vinyl streches and when it does it re-arrainges the molicules in it there for you may get by with draining and refillining, but I sure wouldn't count on it.
I have seen customers who drained and refilled their pool and had very few problems, but most have to replace the liner after draining the pool cause it will shrink about 10 % amd the stress of refilling it will cause a rip. HTH, later, Nat

 

[Pooh_Bear]

I plan on emptying my "pool" during the winter.

The Sequatchie River forms the eastern border of our property.
But in the summer it gets real low, not even knee deep.
I can pump all the water out of it I want to.
Last year I hauled water in barrels for our garden.
This year I plan on pumping water up here.
I have a pump rated 100 gallons per minute @ 50 feet head.
My back deck is 23 feet elevation from the summer river level.
That pump will provide plenty of water to fill the pool
and keep it topped off, and for irrigation in the garden.

Pooh Bear

 

[cmuncy]

Have you thought about looking at the 2000+ gallon poly water tanks?

All you would essentually need to do would be to shave the top off. Looks liek doing this you could add your plumbing fixtures to it with no issues, bury it with no issues, and do what you want with your deck.

 

[dynasim]

A good way to hold things like this together is to use post-tension reinforcment in the concrete.

Essentially, you run plastic tubes the length of the wall. They can be straight, but are optimally curved a bit. After the concrete dries, you run high tensile strength cable through them(I think it is 270 ksi strength, it is important), and pull it up tight. It will pull the corners together, and prevent the concrete from cracking and deflecting. Concrete is strong in compression, but weak in tension, and the constant tension of the steel works with the properties of concrete to make strong stuff. This is how they make parking garage floors.

I don't know enough to tell you specifically how to do it, how tight to make the cables, how thick the concrete needs to be, nor where to get the materials, but there are people who do.

Chris

 

[MossRoad]

I plan on emptying my "pool" during the winter.

Why? No one empties their pools in the winter. Mine is frozen like an ice cube right now. If you drain your pool in the winter you will lose all of your chemistry, the liner may get deformed, rain water and snow melt will wash junk into it, leaves and dead squirrels will greet you in the spring(I know this from experience) and if you have a high water table it could float up like a boat in a bathtub. You may also want to check with your insurance company and local laws regarding a fence and attractive nuisances.

You might want to go to some swimming pool websites and see about pools in your climate and the care and feeding of them.

 

[forgeblast]

Dry stack block surface bonded concrete block walls for HTMs

check them out they use a technique called
Dry stack concrete block walls use surface bonding cement (SBC)
for additional structural strength - no mortar between blocks

SBC was formulated to build million gallon municipal cisterns for water storage

looked really cool.
forgeblast

 

[schmism]

i like setting an above ground pool in a below ground hole.

say you have a 24' round pool, 5' depth.

Dig a 30' dia hole (2-3-4-5?) feet deep. lay draintile along inside edge at bottom with sump pit, backfill with gavel. line outside of hole with off the shelf retianing block.

you now have a ~28' dia hole that you can keep dry.

setup 24' dia pool as you would on the ground, in the hole. (should have ~2' clearance around pool to move. (one could go tigher and work from the inside out)

now you extend your deck to pool edge to cover gap between ground and pool.

if only 2' in ground with a platform deck (another foot) there is now only a 2' wall to climb over.

drain 8" of water off top and cover for winter. remove cover, shock and your ready to go the next spring. My neighbor doesnt empty his and he is on his 4th year with the same liner.