The Best Above Ground Pool Base

I bought a new above ground pool and don't know what way I should go with the install. I'm getting a lot of different answers and warm weather is coming.

My pool is going over a driveway that is made of crushed sea shells. What would you suggest?

gorilla bottom - happy pad-soft foam - sand

I even heard I could use foam insulation board.

I was thinking of gorilla pad with happy pad for a soft bottom without the sand but I don't know...can you help? Thanks Jon



Hi Jon. I prefer sand but only if it is good quality and not to large. Sand is the easiest way to get the bottom of the pool nice and smooth. If enough time is taken in the preparation, I also like the 1" or 1 1/2" Styrofoam 4x8 sheets. I did this with one of my own pools and it made the perfect pool base.

The problem with Gorilla bottom and happy pads are keeping them smooth while you are installing the liner. That, and they are so thin, every little imperfection in the ground shows through. If you go with the foam be sure to visit In The Swim and get the preformed pool cove.

Comments for The Best Above Ground Pool Base

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Apr 03, 2010
best base for pool built on solid rock
by: Anonymous

we are getting ready to install a 18'x33' above ground pool. The location we have to put it up is solid limestone...with no soil...so the challenge is what do we use as fill to level the area. Our plan for now is to put down 3/4 down to allow for water seepage and then on top of it a sand/concrete mix (muck sand). We have not been able to get a confident answer as to if this is the best method for our situation. Any suggestions welcomed.... Ryan



Hi Ryan. That sounds like a good plan to me, best of luck with it.

Jun 05, 2010
Pool with Deep End
by: Anonymous

We are installing a 30' diameter pool with an expandable liner. We have excavated half of the pool deeper with a slope in the center. What do you recommend for the bottom since there are slopes involved? I like the idea of the rigid foam but I'm afraid we will damage it walking around and up and down the slopes spreading the liner. We had thought about carpet padding originally.

Thanks, Bruce



Hi Bruce. I always use washed mortar sand for the base of deep end pools. It sticks to the slopes and is easy to smooth. I have seen carpet used effectively also.

Jun 20, 2010
Installing 18x33 Oval
by: Jeremy

Love your site and I wish I had found it prior to the actual purchase of my pool because I'd have gone for the non-braced over the braced.

My question is this. I live in Texas and the soil is primarily black clay. Our AGP, is going to be counter-sunk 2 ft to meet up with the existing deck that was here when we bought the house. I have almost finished leveling the area with a bobcat because it's really the only thing that works with the hard black clay.

The pool instructions say that my trenches should be down 3 1/4" below the surface. Is that the surface of the ground? Or the surface of my sand base? The pictures are pretty lousy on that.

What is the recommended amount of sand for an 18x33 oval. I did the math and a 2in base is approximately 3 cubic yards. But with the 4 in base, I know I'll need more.

Finally, I've seen you mention Masonry Sand. Is polymeric sand better to use? Or is the Masonry sand the best?

Thanks in advance for your help, Jeremy



Hi Jeremy. I would go with closer to 5 yards of sand. The trenches need to be dug below ground level, not sand level.

Jul 23, 2010
Soft pool bottom
by: Tom

I just had a 24 foot Esther Williams pool installed professionally. The liner is a beaded hopper liner that allows for a 6' deep end. I am concerned with the installation as the pool bottom is very soft and is allowing divets to occur. What is the problem? Too much sand and an improper excavation? Not the right sand? Do I need to use a different type of base? Please help!



Hi. It might be to much sand or sand that was not watered and packed. It is next to impossible to re-install a deep end liner so fixing the problem will probably require a new liner. If it's not to bad your best bet is to use it the way it is until your first liner change. At that time the sand will be packed down and easy to re-smooth. It stays smooth much better the second time around.

Feb 27, 2011
12x24x52 intex retangular pool
by: Joe

I wanted to know how I could setup the base for this pool.

I have Saint Augustine grass in backyard and that is hard to remove.

Is it better to just put foam instead of sand?

I am just starting out and a newbie and getting very overwhelmed with all that is needed.

Thank you for any help!!! Joe



Hi Joe, You really do need to remove the grass, it's the only way to do it right.

Aug 13, 2011
Base question
by: john

I'm building the base for an above ground pool. I've seen comments that say sand is not a good material? how about a sand and mortar mix? If that might be good, what ratio of sand to mortar?

I'm also thinking of laying in two inches to stone dust and using a mechanical tamper to pound it down solid and level.

Which sounds like the better way to go?



Hi John. I would go with just sand and the stone dust is a great way to build the pool foundation.

Jun 05, 2014
Concrete ground
by: Cheryl

Hi I have a concrete base with a 1/4" slope. We are trying to figure out what base should we go with. We keep hearing that sand is no good because water will make it run off. Also that padding was no good as well. We are new at this so we are not sure which route to go. Thanks Cheryl

Hi Cheryl The slope is not a problem. I would go with one of the commercial pads or some carpet felt. Indoor/outdoor carpeting works well also.

Jun 08, 2014
Soil-cement base
by: Shana

Is the soil-cement a good foundation to set an above ground pool on? If so would you use sand or foam insulation before placing the liner?

Hi Shana I have never heard of a soil-cement combo but if it packs solid, great. I prefer a sand base but either works well.

Jan 26, 2015
Cheapest pool base
by: Mallory

I got a 30' circle already dug out. Was going to put down sand just to level it out, then 1" foam board then a tarp over it. I have an intex 10x30 water rise pool. Does this sound like it would work?

May 25, 2016
24' round
by: Anonymous

I saw the comment on the carpet, do you think just carpet pad would work or would it rot over time?

Jun 14, 2018
pad for 21' round
by: Anonymous

I was wondering if a thick rubber mat would be better for the pool than sand? They are horse stall mats and very thick. They can be cut or lined up side by side to accommodate the size. Our soil is gumbo. We used sand and a gorilla pad under our old 28' pool and rocks still worked up. Any suggestions?


Hi Sand works well if the ground is well prepared. At times it needs to be smoothed, packed, watered and packed again. You should not have rocks coming up. In fact, rocks do not come up but sand compacts. Proper ground prep is essential.

Having raised horses I am familiar with the mats. If they lay flat and are well taped together they might make an ideal pool base. I would love to know how it turns out.

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