What Type of Foamboard for a Pool Foundation

[@samwhittemore5614]

**BEWARE** I used the pink colored, one inch, XPS foam board made by Owens Corning under my portable above ground pool which remained set up for four years. A storm caused a tree branch to fall on the pool wall which caused me to remove the pool. I discovered the foam board had been largely/70% destroyed by some kind of burrowing insect that made tunnels throughout the foam. They ate/removed so much of the foam board that the structural integrity of the foam failed. The remaining foam had collapsed and was rotting. The pad site was elevated crushed gravel covered by sand. It was well drained/dry. It was at the highest point of the property. There was no standing water underneath. I think the foam is a good solution IF YOU ARE REMOVING THE POOL ANNUALLY. Otherwise, if your intent is to leave the pool set up, in place for years, I would not choose foam.

[@Hobbitbuilds]

Pinning this post as this is a very valid critique of possible issues with foam. I can say that I too have seen a few little areas where an insect or something damaged the foam, but it was very minor. Yours does sound extensive. This should be a consideration if this will be a long term standing pool. My experience with Intex is that they don't last many years, which may pair up with when an inspection is due. Good points all around, thank you! edit: To add, everyone should be inspecting their pool regardless of using foam or any underlayment. Treating for insects may be necessary on your location. So keep that in mind.

[@karma4872]

Then what can we use

[@JustRay627]

@@karma4872 ants. Your supposed to treat the pool area for ants before setting it up and around the pool every 6 months.

[@Hobbitbuilds]

@@karma4872 You can still use foam, but it is recommended to keep an eye on it for any damage. You would do that anyway with your pool with or without foam under. As also commented, treating around your pool for insects can be extremely helpful.

[@karrieneal4484]

What size and brand pump do you use?

[@Hobbitbuilds]

I just upgraded to the Intex Sand Filter pump. It is often mentioned that whatever size pump intex sends you, to upgrade to the next largest. I've always stuck with what they send in the box and have been fine with that.

[@maryoconnor9065]

Do you have to replace foam every year? My pool stays up year round

[@Hobbitbuilds]

No, for me my foam has lasted about 3 years. But that is partially bc I do tend to take down my pool. it gets more damaged when its not covered, so your mileage may be better.

[@Sir_Sheikhs_Pears]

Greetings from Poland! What about Expanded polyethylene foam (EPE)? Is this type of foam suitable for a swimming pool foundation?

[@Hobbitbuilds]

Hmm, to be honest I am not sure. It is closed cell, which is nice. My initial concern is its durability. Maybe someone else has some experience in that foam type.

[@Sir_Sheikhs_Pears]

@@Hobbitbuilds As for durability, I'm not afraid - this type of foam is used as thermal and acoustic insulation under "floating" floors made of wooden panels, or as insulation for pipes in long sections. However, the degree of compressibility of EPE foam is higher than that of EPS, so I wonder whether EPE is not too gentle for such a weight of water?

[@Hobbitbuilds]

@@Sir_Sheikhs_Pears yeah, that is a consideration. It may provide some cushion, but any irregularities underneath may still be felt. If you go for it let us know, I'd be interested in hearing how that works out.

[@markbanks6620]

Hey I’m actually currently setting up my pool. I’ve laid my foam down. One thing I noticed is if I walk on it the foam starts to crack. If it’s already cracking with my weight…. Wouldn’t it crack with all of the water in the pool from the weight? Does your foam crack?

[@Hobbitbuilds]

Hmm. Crack? So if you are saying that the weight of your foot pushes into the foam a bit that should be minimal issue. If you are saying when you walk it breaks, then that is likely that the ground under the foam is not level enough and it is putting stress enough to shear the foam. The ground has to be close to level. A little "cracking" or sound when you walk should be fine as when water is in the pool, it should evenly distribute the weight and compress the foam equally, if the ground even is close to level.

[@mikesimpson3944]

Not a big deal, but "Styrofoam (R)" is a brand name - like "Coke" or "Kleenex" made by Dupont Dow also nicknamed "Blue Board". ALL Styrofoam is extruded polystyrene (EPS) but not all EPS is Styrofoam. The Pink Stuff by Owens Corning (Pink Panther ad) is also extruded polystyrene. The foam you are calling styrofoam, is actually bead board, which - as you stated, is NOT extruded, and would be horrible as a pool foundation. Dupont Dow Styrofoam can also be purchased with shiplap edges, which make an ideal seam for pool foundations. Unfortunately, the EPS is more costly than the bead board, but vastly superior in quality for this application.

[@SolarProjectsSweden]

I'm using styrofoam (EPS - Expanded Polystyren) under my 13 feet above ground pool. I went with 3 inch/7 cm thick boards, much because I'm located in the northern hemisphere at 60° Latitude in Sweden. The thickness helps me prevent my pool water to cool down from the ground temperature and it's really, really soft and nice to walk on. I've had the foam for 3 years and yes, the surface on the foam is starting to look like the moon with some recesses from walking and jumping feets. It isn't visible when the pool is up and running, but you feel it when you go in the pool. The surface on the foam is still smooth, so there's nothing falling of yet. The visible foam outside the pool is covered and protected with a green, fake grass balcony mat and melts in pretty good with the real grass. The foam I used has the measurement of 47,2x23,6x3 inch / 120x60x7 cm. I used 24 of them for an octagonal shape and in Sweden it had the price of 5,63 USD a piece, 135 USD in total. Worth every penny!

[@Hobbitbuilds]

Nice! I'm starting to get a few reports that at higher lat the foam really helps with temp, that really cool. Ah, Sweden. I hope to visit one day.

[@SolarProjectsSweden]

@@Hobbitbuilds With night temps in the middle of the summer at 46-50°F / 8-10°C, we need all the help we can get to keep the pool warm. Come to Sweden, you will not regret it. We got something for everyone, regardless of what you are interested in. Just remember that a large part of Swedes are a bit reserved and it can be difficult to start a conversation with them, until they start drinking and suddenly becomes super social 😂

[@Hobbitbuilds]

@@SolarProjectsSweden lol, I can totally relate to Swedes! It's official I'm moving this trip up on the list!