Concrete block pool wall

[tybeeware]

Hi,

I had bought a book for building a spa from www.custombuiltspas.com and it is excellent. It shows how to build one using concrete blocks. Some people either tile the spa or just the top. And the rest of the inside is sealed and painted with special paint for this.

He even includes plans for building a lager spa for a swim spa. How reliable would this be? I was thinking of building one about 20' long and 12' wide kind of shaped like below. The floor of the pool would be solid concrete. Can you pour concrete on a slightly sloped ground and keep it from running downhill? I guess as long as its thick enough?

Any suggestions? I wanted to use this method so i can create my own shape, add seats, etc. I would use rebar down the concrete blocks with concrete poured down in them.



Thanks

[matt4x4]

I believe Duraleigh built his pool this way - he'll likely chime in.

[duraleigh]

It's doable. Get set for a LOT of physical labor.

Some thoughts:

At the size your thinking, I would suggest a monolithic pour for the slab...(footing and slab simultaneously) . Extend rebar up from the slab to go inside the block cavity...firmly anchoring the wall to the floor. You would need hoizontal rebar in the walls as well to give them strength. It'll crack if you don't.

Forget painting the inside. Sounds pretty simple but it's not a long-lasting solution. You will need a masonry finish (marcite) or porcelain tile to do a nice job.

Concrete is easily poured on a slope. I would not undertake this task unless you are familiar with concrete, block wall construction and waterproofing masonry or, if you're like me, had a lot of time on your hands and didn't mind the learning process.

Smaller projects (hot tub size) don't require the same strength and are much less complex as a result.