getting nervous about leveling perimeter...

[mcgeggy]

I am in the process of installing a new 24'x52" AG round pool with resin supports. It is going in the same location as the old pool (24'x48" round Doughboy). I will be using a liner pad (Liner Shield) and foam cove. We will basically just rake smooth the sand base because there is no reason to level it - it was level before with the old pool. My concern is in leveling the patio blocks where the uprights will stand. On the old pool, the patio blocks were burried a good 4-6" below ground level of the pool bottom, but on the new pool the instructions say to make them level with the top of the ground. But that means they will be sitting on sand. However, all of the soil where I live is sandy to begin with. Also, the ground that the pool will sit on is lower than the ground surrounding the pool area (it will sit in a depression or "crater" about 4-6" below the existing ground, just like the old pool).

I used a metal pipe and a level to level each patio block against the next, and the they were all level all the way around back to the first block I started with.

I have decided to go back and check them all again using either a water or laser level to be more accurate.

1. Should I be concerned about the sand under the patio blocks? Once everything is up and the outside perimeter is filled back in, how is there a danger of the sand getting pushed out?

2. How important is it that each block by itself sits level on the ground? Is a small level enough to check them against?

I really don't want to be the guy who comes back here and says "Help! My pool is filled and the some of the uprights have sunk!" My feeling is that because the pool area sits lower than the surrounding yard, it should keep everything tightly in place as opposed to a pool that sits on ground that is exactly level with the surrounding ground area.

Thanks for responding!

 

[Bama Rambler]

I'd consider adding more blocks on top of the blocks that are already there if they're already sitting level and are on solid ground. If you take them out and fill under them they may settle differently and wind up unlevel.

 

[mcgeggy]

Well, in that case wouldn't I have to dig deeper under the existing blocks if I added a block on top? I wouldn't want to raise the top of the block higher than it is now - it would no longer be level with the pool area ground surface. Right now the blocks are sitting in the "crater" and level with the bottom of the crater. I'm just having a hard time understanding how the sand would shift - it can't go toward the outside of the pool wall because there is an earthen wall holding it in (the crater wall), and on the inside the weight of the water on the liner would stop it from moving in that direction. I thought the shifting problem was more of an issue when everything is on level ground inside and out, or if the pool bottom was out of level to begin with...

Sorry if I am explaining this badly - I'll try to post pics later...

 

[Bama Rambler]

I think I misundrstood. I thought the existing blocks were below grade and you were going to have to raise them for the new pool. If you're having to move them to different locations then the tops of them need to be level with the top of the ground. Leveling the ground is the most important thing you will do, so taking time to do it right is important.

 

[mcgeggy]

Yes, I had to add new blocks because the tops of the old ones were burried below ground level and the new pool only has 16 supports while the old one had 18 (so the blocks didn't line up anyway). Plus the old blocks were not 2" thick and the instructions said to use 2" thick blocks...

The ground should still be level from the old pool - this is the part I am having trouble grasping. We haven't dug anywhere except around the perimeter to pull out the old blocks (if they were in the way of the new blocks) and to place the new blocks at ground level. The rest of the pool bottom area is a little bumpy with footprints, etc., but it is still fundamentally level. Why would I need to do more than rake it smooth again? Plus the liner pad will help keep the bottom smooth. On the old pool the bottom under the liner (no liner pad) was very bumpy and not at all smooth - but it was level. We never really thought anything of feeling all the ripples/bumps with the old pool so I am not really concerned if it is a little bumpy. But the important thing is that overall the ground is level, which it still should be, especially since it sits in a little crater and there is nowhere for the sand base to go anyway...

So do you think one 2" thick block per support is enough then? Or should I use two blocks (or one 4" block) per support? I just want to know if I am overthinking and worrying about the blocks, especailly since technically they are optional anyway! My understanding is that the blocks should all be under an inch of level with each other all the way around.

Thanks for helping me figure this out!

 

[Bama Rambler]

2" blocks are fine and if you don't mind feeling the little bumps and craters then just raking the sand is fine. I'd get a hand tamp and tamp it a little but it's up to you.

Also, when you go to set the liner, A good shop-vac is your best friend!

 

[mcgeggy]

Oh, I can't wait to see what conundrums I encounter when it comes time for the liner! Thanks for the tip about the shop vac - I am already prepared from all the reading I've been doing on this site.

So I am going to recheck for level on all the blocks with a water level, make sure each block is level by itself using a standard 6" level, then when I start filling the pool I will fill in with dirt/sand the area all along the outside of the pool wall where it is below grade (since it is sitting in the pool crater).

Then I will worry about my well water that I will use to fill the pool... Never had any issues in the past using it to top off the pool, and in fact last summer I had to empty a third of the water due to a "chlorine block" or something where the chlorine wasn't working, and never had any red or muddy water when I filled it back up. So my impression is that there is not enough metal content in my well water to be an issue...

 

[Bama Rambler]

You can take a sample of your water to the local pool store and have them test it for metals but if you haven't had problems with it in the past you're probably fine.

 

[NWMNMom]

Just keep in mind that its really the area the bottom rail and uprights sit on that must be level all the way around, anything inside ir outside that "line" is irrelevant except as to asthetics, ie, bumpiness. If your bottom rail and uprights are level, the pool is level.