Should I use XPS foam for this build?

[eyedoc_01]

Hi pool people,

Question is about XPS foam. I am putting in a 27' Saltwater Aurora above ground pool. I've dug down to undisturbed ground, and getting the final level done.

I have seen seen builds that incorporate XPS foam sheets. In my case, I can just put down 3" of sand and level it. Or I can put down 2 1/4" of sand and then XPS foam (with triple taped seams). Planning on an Armor Shield on top either way.

Is there a reason for XPS with this setup? It will cost several hundred dollars for XPS for this size vs. $30 for another cubic yard or so of sand for the last 3/4". If I just go with 3" of sand and no XPS, the Armor Shield will still protect against grass/critters/footprints in the sand.

Thanks in advance, you've all been a big help!

 

[Texas Splash]

You might be past this point already ............ but I suspect the main concern would be for potential water run-off if you get flooding in your area. But if that's not an issue, then sand should be fine. You might also have edging or some other protection around the perimeter of the pool anyways to keep water from washing away sand.

 

[eyedoc_01]

So here is the build...on the far end was planning on a retaining wall. It will have a drain at the base and a proper drain chimney, so we should get minimal drainage. On the near side it will only be about 4" below grade, looks like more because of extra dirt.

So there shouldn't be much water coming in, and it will be down in a depression anyway. Is the problem with sand that if it's too thick it washes away more easily? Does the XPS help keep it in place somehow?

 

[Texas Splash]

Sand is certainly very popular. The choice between sand versus other products is a toss-up between personal preference (comfort), conditions of the soil, water run-off, rocks, and the potential for aggressive nut-grasses and other weeds that may try to penetrate the liner. But with sand, propositioned drainage, an an Armor Shield I suspect you should be fine.

 

[CT-Steven]

After leveling (were within 1/2") I added about an inch of sand to fill in the few inconsistencies (divots, etc.). The I put in 1" XPS foam board insulation, taped the seams with 4" Gorilla Patch & Seal tape. Then placed a tarp over it. Also don't forget to spend the time to kick out the wrinkles of the pool floor by filling with about an inch of water.

 

[eyedoc_01]

Thanks Steven. Sounds like what I'm thinking. Sand for rough level, XPS for top layer, tarp/Armor Shield on top of that.

Why did you end up deciding to go with XPS board?

Main cons I see are cost and hassle of install and taping.

Pros seem to be that it's a very smooth and flat surface with no chance for footprints, another barrier to weeds/bugs/critters, and less sand to wash away.

 

[CT-Steven]

XPS is extremely water resistant and subsequently mold resistant. Also like pool pads I do not see weeds being able to penetrate this barrier. For the 9x18 pool, I covered about 11x20. I cut where the legs are sitting and used 2x12 pressure treated wood to support the legs. I think it took me maybe an hour to cut and tape it all.