Cinderblock pool walls?

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40 year old pool

Cinderblock pool walls?

Postby 40 year old pool » Wed 15 Apr, 2009 08:20

I am in the midst of springtime opening a cinder-block pool built by my father and a couple of friends - 40 years ago. Don't let anyone tell you it can't be done or that it's doomed to failure. However "lunaticfringe" posted that you should be able to knock it off in a weekend - well that's just fallacious, I was only about 5 when they built it but I distinctly remember it being a lot of work - also one of the guys was experienced with concrete which certainly helped.

My dad told me all the engineering was provided by the local block manufacturer - perhaps that's a good source for info. They used the filled block & rebar method for the walls, sealed with a plaster layer, and then coated with a finishing layer. The floor was formed with a steel mesh and rebar then filled with poured concrete. All deck surface options are available - he used ledgerock flagstone ( hey it was the '60s ), standard plumbing and standard pool equipment.

I live in a northern climate so the pool is subjected to annual freeze/thaw and requires normal winter shutdown procedures for pump and filter. Water level is lowered to below the skimmer. Springtime maintenance normally consists of fully draining to clean out leaves and debris ( pool is oddly shaped and doesn't have a cover ), cleaning with a pressure washer, chipping out any loose bits ( around the iceline gets a little rough ), then resurfacing with a waterproof masonry coating. The coating I've used is a dry powder that's mixed with water (I also recommend using the available acrylic fortifier) to a soupy consistency that is applied with a whitewash brush. Colours are premixed white or grey but tinting is available for different colours. I use Quikrete brand because that's what they sell at the local building supply - I imagine there's other manufacturers as well.

This year the surface is better than ever with the exception of two small areas ( total about 2 sq ft ) that will require a little extra maintenance. Also in the last couple of years I have had some minor repairs requiring filling with hydraulic cement, applied by hand and allowed to dry thoroughly, before applying surface coating.

So, you can see there is some work involved but there are numerous positives as well - the major ones being:
- good technique for DIY
- unique designs possible (ours is Y-shaped with an extra long shallow end - great for little kids)
- no vinyl liner ( how many liners would we have used in 40 years, at least 2 or 3 I'd guess, and they go for $3,000 - $4,000 a pop around here ); you can let your dog swim ; the pool area doesn't have that plastic smell ; it seems easier to keep the water clean with less chemical use
- no plastic coping
- you can make it a different colour every year. I like white as it makes the water look crystal clear and clean. My dad most often did medium green walls and white floor, that looked good too.
- I don't know the current cost comparison but I imagine the upfront costs are still lower
- I saw somewhere that the design life of this method is 20 years - but this pool's 40 year track record in a northern climate speaks for itself - it's durable !!

I'm not saying this method is for everyone but it might be right for you - good luck !!

Block Pool

Cinderblock pool walls?

Postby Block Pool » Sun 19 Apr, 2009 12:55

40 Year Old Pool,
We moved into a house where the previous owners did just as your dad did. Ours is still in great shape too!

Last year we had a hole in the liner (and didnt know it then). We thought there was a leak in the main drain, thanks to a local pool company. We removed our liner with no chance of putting it back in. When we removed the liner, we have found that there are two or three blocks that have moved away from the wall.

Have you ever had to "push" a block or two back in place? They are out approx 1-1/2 inches. How can you fix this?

Also, what do you use to "paint the pool"? Im getting tired of the expensive liners every five years or so. Have to buy one this year since we destroyed ours last year.

ive found what u need!

Cinderblock pool walls?

Postby ive found what u need! » Sat 25 Apr, 2009 00:47

go to its perfect!
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Cinderblock pool walls?

Postby echo512 » Mon 25 May, 2009 17:15

Sorry to post additional question, but as far as using cinder block walls, etc., I'm assuming all of this needs to go through a structural engineer for stamping, and submittal to the city for approval before digging/starting?

Is there any detail to the correct mixture needed for the concrete:
1) poured as a foundation
2) poured into the cinder blocks

Also, what size rebar, and number per hole in the blocks?

How to make curves in the design?

Any other good sites with this DIY in mind?

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Cinderblock pool walls?

Postby QUESTWORLD » Sun 26 Jul, 2009 21:44

have you gotten far with building your cinderblock pool? I will be starting mine here in the next month poured floor and setting the first row in with that and rebar. Stack and fill after that for the wall. Cost that i have estimated so far are way below any other option esp with doing most of the work myself.

Cinderblock pool walls?

Postby cwalker1960 » Thu 27 Aug, 2009 07:43

Seems many are looking for ways to save money building their own pool. Building the walls with concrete block certainly is an option. As mentioned further back filling the block is a must to ensure that the block don't move and cause cracks in the plaster. 1 # 3 or # 4 rebar per block cavity will be sufficient before filling the block with concrete. A regular 3000 psi block fill concrete mix will be fine for filling. Another choice to save money is to hire the subcontractors yourself. Many pool companies use sub contractors to spray the shotcrete for the pool shell. The subs aren't the ones overcharging, it's the pool companies/contractors. By using shotcrete you have unlimited options for shape, steps, benches, swimouts and ledges. By time you figure the cost in block, laying them, the concrete to fill them, and all the labor involved, you may find that hiring a shotcrete subcontractor affordable. It will cerrtainly make your job a lot easier. For more information check out

Cinderblock pool walls?

Postby patrickspools » Fri 30 Oct, 2009 08:17

I work on liner pools made from cinder block all the time. They are not even filled with anything. These pools are ancient and have no problems. I even just chisselled a hole out through one for a problem. I also have a customer that dusted over his and it did not crack for about 10 years. I don't know if his blocks were filled....knowing him they probably were

Cinderblock pool walls?

Postby kenected » Sat 09 Jan, 2010 03:38

Hey I am not alone! I just started my cinder block pool that will have a Jacuzzi, 3 water falls, and a grotto. The way I am building mine is this: I dug the hole and squared it off at the bottom and wall connection. Then I dug a 12" x 12" footing for the walls. I used a lateral 1/2" rebar with 1/2" vertical rebar in the footing. Verticals are in every cell of the cinder block. I poured a continuous footing setting first course into footing level with step ups as needed for design. Then every other block I ran rebar across the bottom of the pool up into the side walls. I then stacked 3 courses of block and ran horizontal rebar 1/2" wire tying it to the verticals (rebar). That is as far as I have gotten so far, still working on walls. Will keep you posted!

Cinderblock pool walls?

Postby Kwanders » Thu 21 Jan, 2010 14:53

I am planing to build a Lap pool...8' by 15'. I want to build it about 5' deep. 2' underground and 3' above ground using 8" by 8" by 16" Questions... If I place durawall at each course above ground. Will my wall be strong enough to stand up againest presure of the water.... And can I tile the cinder block?
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My Pool: 20 x 40 rectangular gunite pool with attached spa and kiddie pool. Cast stone coping with waterfall off the kiddie pool. Goldline automation .
Location: S.C.

Cinderblock pool walls?

Postby cwalker1960 » Sat 27 Feb, 2010 04:27

Not filling the block is fine if you plan on putting in a vinyl liner. This is not acceptable if the pool is to be plastered. Plaster doesn't give, it cracks.
As for pouring a footer , laying the block walls then pouring the floor,, if you're planning on plastering this pool , it wouldn't be the way I would go about it. Footers can settle , then you have a leak around the perimeter of the pool. With the footer dug as you have described , tie all the steel in the floor and pour the footer and floor at one time ,, then lay the block. We pour floors on big commercial pools all the time ,, I'm talking 70' by 150' by 17' deep. and this is how we do it. I have seen pools with the floor poured later and they leak period.
For the one wanting the pool "x" feet out of the ground. i can't remember your dimensions , but water pressure ca be quite substantial. Straight walls don't have any support built in. it would most assuredly be worth your time to get an engineer to look it over before proceeding.
And I have said this before on this forum . People , get an estimate from a shotcrete company before you spend all this time and energy. You may very well find out that it is cheaper and much faster in the long run to hire this part out.
This information is not coming from someone trying to take your money . i seriously doubt that I would be the one shooting the pool for you anyhow unless you happen to live in SC. just trust me on this , I'm trying to help. For more help visit how to buildan ingroundpool

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