4" slabs or timber?/new pump/new cleaner/new heater advice

Jackie G

Well-known member
Jul 19, 2017
124
Kent
Well, here we are again, having to empty the pool and re-level or re-lay some stronger slabs. The pool was bowing last year, and we were advised to empty, and make sure the ground was level. So we did that, and used some new concrete slabs. We used a water level and all looked good. We filled her up, and overnight we had broken slabs. (I suspect the soil was built up despite my pleading not to do that, plus the slabs were nowhere near thick enough).

So back we are again. The pool is bowing on one side, which is the side the slabs have broken. We are going to empty it again, and this time I'm determined to do it properly...Which will be best to use? 4" slabs, or the pressure treated timber? I'm tempted to use the timber which will have more give in it and less likely to crack again....it's also what Intex recommend. What do you guys think?

I'm also wondering on a very practical level, how do you dig down the right amount without going too far? I'm so worried that we will dig down too far, and then end up in same position....we are trying to avoid digging the whole area of the pool which will be a nightmare.

Also, so that we get more use out the darn thing this year, want to upgrade our heater. we currently have one that takes the air heat source pump which basically means it only ever heats the temperature to the outside temperature which means in the UK it's quite cold quite a lot of the time! Any recommendations on best ones to use for AGP which is 18ft x 9ft?

I'm not finished yet! I'm a demanding so and so ;) Robot cleaners for AGP - which ones are best that can climb and scrub the walls and save me having to get up at 5am to do it?

And lastly, our pump is probably not the best. What size is best for our size of pool, which can accommodate a decent heater and a robot cleaner (does it need a pump for this?)

I know you guys will have some good advice so am thanking you in advance and hoping that we can get this pool working for us so that we can use it :) I'm determined grrrrrrrr
 

kellyfair

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Jun 29, 2016
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So, you are right that your blocks were way too thin if they broke the first night. Certainly you can use pressure treated wood, but get the good stuff that survives ground contact for years. Here in FL wood rots pretty quickly.

The water level is how you know how far down to dig. Tedious, but if you don’t want to dig up the whole pool area, that’s the way. It might be worth re-leveling though, since you’ve had recurring issues.

I can’t help with heater... the sun is my heater! And I’m not familiar with wall-climbing robots for Intex-type pools, but a true robot doesn’t need a pump.
 

BoringDamo

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Aug 3, 2020
69
London U.K.
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How big is your heater now? What months are you expecting to use your pool for?

I’ve got an 18’x9’ Intex which I got end of last summer. I’ve just bought a new air source heat pump at 15kw which the sales folk said was the right size for this pool for May to end of Sept swimming (Assuming your location is Kent Uk I’m the other side of the M25 clock from you so broadly similar weather, if we were in the states we’d probably say we were neighbours).

I also struggled to find 4” pavers, the best I could find was 2” (well 900mm x 600 x 50 which I cut in half to give a 600 x 450 paver). They seemed to be ok for the 8 weeks the pool was up last year. I think it also depends on the strength and contact area with the ground underneath and the strength of the concrete used to make it.
 

Jackie G

Well-known member
Jul 19, 2017
124
Kent
So, you are right that your blocks were way too thin if they broke the first night. Certainly you can use pressure treated wood, but get the good stuff that survives ground contact for years. Here in FL wood rots pretty quickly.

The water level is how you know how far down to dig. Tedious, but if you don’t want to dig up the whole pool area, that’s the way. It might be worth re-leveling though, since you’ve had recurring issues.

I can’t help with heater... the sun is my heater! And I’m not familiar with wall-climbing robots for Intex-type pools, but a true robot doesn’t need a pump.
Thank you! We are going with pressure treated timber this time. We call them sleepers here in the UK but they are 4" deep. We are using a water level to ensure level across all legs and inside of pool (we did use water level last year). And we are going to replace all the slabs with the sleepers, not just the broken ones. Just in case....
We could always move to sunnier climates I guess...!
 

Jackie G

Well-known member
Jul 19, 2017
124
Kent
How big is your heater now? What months are you expecting to use your pool for?

I’ve got an 18’x9’ Intex which I got end of last summer. I’ve just bought a new air source heat pump at 15kw which the sales folk said was the right size for this pool for May to end of Sept swimming (Assuming your location is Kent Uk I’m the other side of the M25 clock from you so broadly similar weather, if we were in the states we’d probably say we were neighbours).

I also struggled to find 4” pavers, the best I could find was 2” (well 900mm x 600 x 50 which I cut in half to give a 600 x 450 paver). They seemed to be ok for the 8 weeks the pool was up last year. I think it also depends on the strength and contact area with the ground underneath and the strength of the concrete used to make it.
Hello neighbour! We have same pool as you. We have an air source heat pump. it's a good one, but of course it only heats the water to the temperature of the outside. When it's sunny and hot, it's great. But those days are few and far between ha ha! May - August are the months the pool tends to get used. I have found September gets far too cold very quickly.
We decided to go with sleepers which are 4" deep. Fingers crossed this will work this time. Strict instructions to dig down to virgin earth and not build up again.
I'll keep you posted
 
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BoringDamo

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Aug 3, 2020
69
London U.K.
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I didn’t even think of railway sleepers, if I have issues with my pavers I’ll probably upgrade to those.
On the air source heat pump they should be able to heat the pool warmer than the outside air, it’s just they get less efficient (and thus more costly to run) the colder it gets. They also reach a point where there aren’t enough hours in the day to heat the pool before heat loss exceeds amount that can be put in.
I’m really hoping mine allows me to get at least to the end of September if not into October. What size heat pump do you have? I’ve got a 15.8kw so will be interested to see how it goes (I’ve also got Solar PV on the house so hoping it covers some of the cost of running the pump)

Do you leave your pool up over winter? We didn’t but it’s been a bit cold to get it up for this year. I’m hoping in a couple of weeks to at least get it up and filled even if it’s too cold to use.