Size of XPS foam under INTEX 32x16 pool

[maxwellitician]

I would like to hear from people that have done the foam under their INTEX ultra frame 32x16 pool. What size did they use of the foam? And how did they install it?

Below are some details about my setup:

• I have a slope in my backyard. So I built 40'x20' foundation box, and filled it with 3" of gravel and 4" of stone dust. They were leveled and compacted.
• My next step is to add a heavy duty tarp on top of the stone dust.
  • 20' x 40' Heavy Duty Double Laminated Silver Tarp Covers
• Now i want to add 16 panels of 8'x4' XPS foam to be directly under my pool liner.
  • Owens Corning FOAMULAR 150 1 in. x 4 ft. x 8 ft. R-5 Scored Square Edge Rigid Foam Board Insulation Sheathing-20WE - The Home Depot

Do i need to add more foams? Your thoughts?

 

[kellyfair]

@jseyfert3, can you comment on the plan here?

 

[jseyfert3]

I used 1” tongue and groove foam. I did the T&G with the assumption that it may have less visible seams. Not sure how big of a different it made, as only two sides have that, the other two are square.

I did not use a tarp at all. I put the foam directly on the tiny rock/sand mix I have under my pool. I didn't buy it but I'm guessing it's similar to the rock dust you mention. I then put the pool up directly on the foam.

I staggered the foam like bricks in a wall to try and avoid seams that ran the length of the pool, again mostly for looks. Again not sure how well that worked, the seams are hard to notice, unlike the liner wrinkles I didn't get completely out.

A lot of people here recommend triple taping the seams with gorilla tape. I found extra wide Gorilla tape at Menard's and used a single strip of that instead of triple tape. It is pretty hard to unroll though. Oh, and GET THE SILVER TAPE! We did this in full sun and the black gorilla tape was uncomfortably hot on the foam almost immediately (after being stretched out while being pressed down) and got quite hot enough to burn after sitting longer. Silver Gorilla tape should stay cooler...at leat that's my guess, no proof there.

 

[maxwellitician]

@kellyfair - Thanks for the referral.

@jseyfert3 - Thanks for sharing your thoughts. Should I make the foam larger than the pool base (i.e. the part touching the ground)? If yes, do you know what is the size of the bottom side of the liner if my pool is 32'x16'?

 

[Caffeine Chemist]

I used 1" FOAMULAR brand. I triple taped the corners and taped the seams with Gorilla tape

 

[jseyfert3]

Thanks for sharing your thoughts. Should I make the foam larger than the pool base (i.e. the part touching the ground)? If yes, do you know what is the size of the bottom side of the liner if my pool is 32'x16'?

It should stick out from under the liner do the liner doesn't stick off the edge, but should not be under the legs