"> When to buy and use wall foam for an above ground pool. READ THIS BEFORE BUYING – Above Ground Pools Know it All

When to buy and use wall foam for an above ground pool. READ THIS BEFORE BUYING

Usually, when people buy an above ground swimming pool, it comes as a package. This means that you don’t just buy the actual pool. You buy a package with everything you need to have an above ground.

Typically, a pool package will come with the pool itself, a skimmer box/return, a liner, a pump/filter pack, a ladder/steps, a maintenance kit, and a start-up chemical kit. There are other options, add-ons, and upgrades that can come with the pool package too. One of them is this thing called pool wall foam.

You should only buy wall foam for an above ground pool if the inside of the pool’s wall has a lot of surface rust. To install wall foam on a brand new pool is a waste of money.


The longer-lasting traditional above ground swimming pools (not the soft-sided cheap Intex/Coleman type) come with a metal wall and a vinyl liner that goes inside and against the wall. The metal wall holds all the weight of the pool’s water and vinyl liner prevents the water from leaking out. Simple, right?

As per the design of the pool, the liner lays directly against the inside of the wall. This direct connection between the two cause no damage or wear unless the inside of the pool’s wall is rusty.

When the inside of the above ground pool’s wall has a lot of surface rust, laying the liner directly in contact with that rusty surface may take some life from the liner. So to protect the new liner from being damaged by the rust, a thin layer of rolled foam sheeting is glued onto the inside of the pool’s rusty wall. Then the new liner can go in because there is a thin layer of wall foam in between the old rusty wall and the new liner.

This product is called “wall foam”. Wall foam comes in a big continuous roll and is only about 3/8” thick. To keep the foam on the wall, spray glue is applied to the wall of the pool and the foam so it will stick on the wall. Important- A good quality spray glue with a lot or body should be used.

Thinner spray glue (like what is available at Home Depot) will not be as effective at getting the foam to stick on the wall.


As a guy who has installed above ground pools for more than three decades, I have developed a few pet peeves (and maybe a nervous twitch). One of my bigger pet peeves is installing wall foam on a brand new pool.

I want to be as clear as I can here. A brand new pool wall and a brand new pool liner do NOT need a layer of wall foam in between them!

There are only a couple of retailers that sell wall foam with a new pool package. It drives me a little nuts. Whenever I go to install a new pool and it has wall foam with it, I know one of three things happened.


The retailer wanted to add more to the sale

Gladdon spray glue used to attach wall foam to an above ground pool wall
Expensive top quality spray glue must be used with wall foam

Every little thing you buy with a pool package increases the profit on the pool sale. $60 to $100 isn’t much when buying something that costs a couple of thousand dollars, but it adds to their bottom line and you’re buying something you don’t need and has no benefit whatsoever.

When I see wall foam included with a new pool package, it tells me something about the retailer. The Pool Factory is one of the biggest sellers of above ground pools on the internet. They, unfortunately, will sell wall foam with new pools. This says negative things to me about them. Jus’ sayin’

The salesman doesn’t know any better

Above ground pool guys come and go. Especially internet pool salesman. Most of those guys were selling fake Christmas trees or something a couple of months ago and really know nothing about pools.

They look on their info sheet and see the available add on products and when someone wants to spend more, he suggests wall foam and glue.

Oh, the salesman will have some spiel (sales explanation) about why you want it that he will read to you, but he won’t know what he is saying beyond just repeating the words he is reading.

The future pool owner (buyer) will ask for it

I have a friend who sells these pools and knows what he is talking about. A couple of years ago, he sold this lady a pool and it had wall foam with the package. Knowing that I would be installing the pool, he texted me. Saying “Hey man, don’t think I sold this lady the wall foam. I tried to talk her out of it but she insisted”

I told him “no worries” and when I went to install the pool, I asked her about the wall foam. She told me that she read online that the wall foam will help insulate the water better. It would keep it warmer in the cooler swim months and cooler in the summer. I said OK and built her pool and put wall foam on her new wall.

The internet is full of information. Believe it or not, some of it is wrong. Here are some of the things that I’ve seen and heard about foam that is wrong:


Wall foam applied to a resin above ground pool wall

Wall foam insulates the pool’s waterFALSE

While it is true that foam is an insulator, 3/8” thick of pressed foam won’t maintain the temperature of an above ground pool any longer than if it wasn’t there. Period.

In truth, the temperature of pool water (unless it’s heated or chilled) has mainly to do with direct sun exposure. I always hear about above ground pools supposedly being colder or warmer than in-grounds because they are out of the ground with walls that either heat up or get the pool water colder by being exposed by the elements. I have found this most often not to be true (at least here in Florida) in reality.

Even if the temperature of above ground pool’s water was different from in-grounds due to its walls being out of the ground, a little layer of foam would not make any difference as an insulator.

Wall foam will help to prevent the wall from rustingFALSE

rust spot on above ground pool wall that had wall foam installed
This pool had existing wall foam installed on day one and there is still rust

The reason an above ground pool’s wall rusted is not always clear. Usually, it’s from a leak that was never patched or from the pool having a bead channel that allowed water to come in from the top of the wall.

Regardless, wall rust has something to do with moisture not being where it’s supposed to be for too long. A thin layer of foam in that area has no effect on the damage that moisture can do to the wall. Period.

You can think about it and come up with a logical reason that the foam will help or you can read on the internet about some guy’s scientific reasoning. But in the real world, the foamed walls get just as rusty (if not more so) as non-foam coated walls when the conditions for corrosion is present.

Foam will make the liner more durable against punctures or holes made by kids or dogsFALSE

It doesn’t matter if there is a layer of foam behind the pool’s liner or if it is pressed hard against the wall, have a kid poke it with something sharp or have a dog paddle it with his paws and the result will be the same.


wall foam applied to a rusty above ground pool wall

This is simple. You should only buy wall foam when the inside of your existing above ground pool has a lot of surface rust on it.

To make this even more simple(if that’s a real term), you will only know that the inside of your pool’s wall is rusty when you take the liner out before or during a liner change. So, the only time you will buy foam is when you are changing the liner in your existing pool.


Wall foam for an above ground pool with glue and about to be applied
This wall didn’t need wall foam

When you drain the pool (or if it drained itself) and you cut the liner out of it, inspect the inside of the wall. If there is only a couple of small areas where there is rust, you can put some pieces of duct tape over them. Or, duct tape some pieces of thin metal over the rust areas. This will be all you need to protect the new liner.

If there is a lot of surface rust everywhere, then you have two options. The first is to buy the foam and good quality glue (recommended). Note: The same roll of wall foam will work on any height pool.

The second is you can get in the pool, sand down all the rust areas, apply a product that stops rust, then paint it all (not recommended). The biggest problem with doing this is that it is a hell of a lot of work. And the work will only prevent the new liner from being damaged. It won’t stop the corrosion process that has begun all over the wall. Nothing will stop that.

With using the wall foam, the rust on the walls will not need to be worked on. The wall will continue to rust more but the replacement liner won’t at all be affected by it. The wall will continue to rust anyway, so that makes the wall foam the easier choice.


When inspecting the rust on the wall, take a screwdriver or something like that and poke the wall. If the screwdriver goes completely through the wall, that is bad. At that point, depending on where it has rusted through, you may want to reconsider buying the wall foam OR the new replacement liner. The wall may be too damaged to hold the water for the pool for much longer.


Dan writes with the knowledge of having 35 years (and counting) in the above ground pool industry.

15 thoughts on “When to buy and use wall foam for an above ground pool. READ THIS BEFORE BUYING

  1. Hey Dan – glad I found your site, you saved me a couple bucks.

    I am wondering though – my pool was damaged over the winter. I definitely need a new liner but am not certain if I need new pool walls. Is there a way I could send you some pictures and have your opinion? The pool guys in my area said it needs to be replaced, but I feel like they might be trying to sell me a pool.


  2. Hi Dan,I am in the process of putting up a 16ft x 32ft pool.I live in Az so it is very hot now.I was thinking of putting wall foam on the outside of the pool to keep the sun uv off of the vinyl.I was also hoping to keep the pool a little cooler.
    What kind of cover would you suggest to keep the heat from sun from heating up the pool?
    Thank you

    1. Putting wall foam on the outside of the pool wall will not work well and look horrible. If you want to insulate the wall from sun exposure, then I suggest something attractive like wood planking or something. And I don’t recommend any type of insulation as you goal is to prevent the wall from getting hot by direct sunlight, not keeping heat or cold in (which doesn’t work anyway as pool’s surface transfers temperature energy too easily)

      I suggest a solid cover light in color.

  3. Hi Dan I am trying to figure all this buying a new pool thing out up here in Canada and the wall foam thing hit a nerve 🙂
    I am getting an above ground pool – that is “salt friendly” 12×24 Element pool … I was told that putting the foam on the inside might help with future corrosion from the salt????? Is that crazy?
    I am now getting the cartridge filter rather than the sand (thank you)

    I am trying to research everything but damn there is so much info out there (and as you said not all true) …

    1. Hi. Yes that is crazy, but people and retailers really don’t know what they are talking about. And that doesn’t stop them. It doesn’t even slow them down LOL

      Good luck. I’m sure you will get the right set up.

  4. Hey dan
    Pool wall has some tiny holes that were weeping due to liner leak.
    Some size of pins. Some maybe 1/16”
    Foam sounds great for this with new liner?
    Just concerned about overall wall strength?

    1. Is your pool wall made of aluminum by chance? If so, take the liner completely out and look for pinholes everywhere. Shine a light at night if you have to to see them all. There may be hundreds that you don’t notice.

      Verify the amount of pinholes before wall foam and changing the liner. Use your common sense to determine if there are too many to proceed.

    1. Unless you are covering a lot of rust on the wall at the bottom, start a couple inches from the top of the wall. If rust at the bottom, start further down to cover it.

  5. My 18′ round above ground pool has a pool foam. The vinyl liner is worn and I will be replacing. Should I replace the pool foam when I replace the liner? Or can I leave the old pool foam on the walls and install the new liner over it?

    1. Usually you can reuse the wall foam but not always. You’ll have to remove the liner the know for sure. If just fallen off the wall, you can re-glue or duct tape it back on the wall.

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