New Intex Pool Underlayment Questions

I have a leveled area for my new 9 x 18 Intex Ultra Frame Rectangle pool but have some questions I hope owners with rectangle pools might be able to assist with or share their experiences.

What did you used under the legs and what size(height especially), along with the size of foam you may have used? I don't want to use sand underneath as I have heard stories of it shifting under rectangle pools.

Has anyone had experience with using square pieces of wood under the legs vs one single long board as I have seen in a couple of posts? I plan to use wood, not pavers as most pavers break over time.

I am worried about using 1.5 inch board with 1 inch foam, is that going to cause it to not be level if the pool sinks down into the foam and the legs being up a bit higher??

Will the foam squish out a few inches as we fill with water? If so, then I should not let the foam meet the wood for the legs, correct? I should leave a few inches between the foam and my wood for legs, right?

Thank you,
Rkipper

You probably should talk to the company from whom you're thinking of buying the underlayment foam for installation instructions. Remember water weight 62.5# per cubic feet, so if your water is 4' deep, each square foot of pool bottom has 250# over it.

The idea of wood or pavers under the frame's outriggers is to keep them from sinking. Therefore, their ideal height is probably ground level, meaning you bury them.

Foam under a liner can INCREASE the chance of puncturing it, with small pebbles or stick in the pool. Better to clear the site well, and use a heavy duty tarp, cut to fit, under the pool instead.

Sand moves, if water moves it. If water doesn't run under/along the pool, it isn't necessarily an issue.

Thank you for your ideas.

We had our intex set up by a pool installer. They used vermiculite and packed that down and then laid sheet foam insulation duct taped together over that then a thin piece of rolled foam. Intex went on top. They used patio blocks under the feet and many broke. I'd suggest using wood instead. It is less likely to break than the patio blocks. Make sure it's about 12" wide as the legs will shift when you fill the pool. After we filled it we back filled around the pool and over the vermiculite with pea gravel. Add stepping stones and instant backyard oasis!

Here's a link to the photos of our setup. https://suzyabbott.shutterfly.com/65