Base for Under an Above Ground Pool

by Amy
(Beloit, WI)

My husband and I are getting ready to put up an 18' x 48" used above ground pool. I remember reading in one of your posts that you said sheet insulation could be used to place the pool on.

We have an existing area where we have enclosed the area with landscape timbers in an octagon shape because we used to have an 18' Intex AGP with the inflatable top ring.

We have about 6" of sand in there, but I am aware that we probably need to remove the sand, correct? My main question is, which type of insulation do you recommend? The white kind that crumbles or the pink kind that breaks into clean breaks when you break it or cut it? Or, am I thinking too thick of insulation? I was thinking of using the 1/2" thick stuff.

Also, when using this, does it get laid just to the cement blocks that the uprights sit on? Or is there another way? It all is still supposed to sit level with each other correct?

I am hoping to get the pool up next weekend, so I really want to know what we need to do. We plan on leaving a small amount of sand at least to level the area before placing the Styrofoam insulation under it.

Also, should we tape the sheets together with duct tape? I really love getting your pages, I have learned a lot about pool care and maintenance from them!

It is great that you

offer this service for people like me that otherwise would be clueless. Thank you so much!!

And thank you.

Hi Amy.

I would remove just about all of the sand if you plan to use the foam base. Leaving a little for the final smoothing is fine but make sure the rails and footplates are on level ground. Putting the footplates on blocks is fine and they should all be set at the same level. The ground between the blocks should be level and firm. At this time I would have the sand moved in towards the pool center and out of the way.

After the wall is installed the sand can be spread out and leveled. The sand should cover the blocks and bottom rails and be an even 1/2" to 1" across the bottom of the pool. I would not go any thicker because it will cause more of a footprint problem.

The foam can now be installed. Either type of Styrofoam is fine and 1/2" would be minimum thickness. The plain white 1" 4 x 8 sheets work just fine.

When using foam I always recommend the preformed pool cove be used also. This goes on next, over the foam. Everything should be well duct taped, all the joints in the foam sheets and the cove.

I have written a lot about using this type of pool base. Read through the related pages for more information.

Pool Cove and Foam Pads

Gorilla Pad, Happy Bottom and Foam

Styrofoam For Above Ground Pool

The Best Above Ground Pool Base

Base For Above Ground Pool

Foam Pool Base

Pool Floor Pads

Pool Underlay