Polystyrene Foam Insulation for Pool Bottom - Pink Vs. Blue

Jul 21, 2012
24
We are putting up a 15 x 30 steel wall pool. We've already purchased a foam cove. Our soil is quite sandy so we're thinking we can get away with not bringing in sand if we use a 1/2" or so of sifted soil to cover the inside framework and then put down a layer of rigid polystyrene foam insulation to make a smooth bottom. We plan to fit it very tightly inside the pool walls and tape with lots of duct tape to avoid any separation gaps. Home Depot carries a 1" blue Polyshield insulation. It costs $9.63 per 4' x 8' sheet. They also have the 1/2" Owen-Corning pink insulation board for $13.76 per sheet. (The 2" isn't available here and would probably be out of our price range anyway.) The blue sheets weigh 1 pound and the pink weigh 2.7 pounds so I'm guessing that the pink insulation is much denser. The pink insulation description states that it is impervious to moisture. I don't know if this is the case for the blue insulation. It would cost about $65 more for the pink than for the blue. Has anyone used either of these? We don't have money to burn but this will be a permanent installation so we want it to hold up for a long time. Any thoughts on whether the pink is worth the extra money or would the blue work just as well? Thanks in advance.
 
Re: Polystyrene Foam Insulation for Pool Bottom - Pink Vs. B

I believe that polysheild is expanded polystyrene, where the pink stuff is extruded polystyrene. Extruded polystyrene is what you want...it is much tougher/stiffer. I would guess that blue stuff a would dent way too easily.
 
Re: Polystyrene Foam Insulation for Pool Bottom - Pink Vs. B

I just put up a15x30 steel wall pool. I used the foam board for the bottom of our pool. This is a great idea. I used the board that is white on one side and like alluminun foil on the other side and is 3/4 thick. I never though to check the density of the foam"I wish I had". Our home depot only offer the white or blue . Which was more expensive so I opt for the cheaper. Our pool has been up for about 2 months and the base of the pool is nice and smooth. The pool company sold me a roll out foam base that was 1/4" thick. I used it as a vapor barrier. Don't know if it was necessary on not. But, since I bought it I use it. When I put in the foam board I used gorilla duck tape to tape the seams together. I also staggered the width seam like you would on a roof deck. Now, here's what happen the liner squeezes in between the some of the seams. Everything seems to be ok and you can barly feel the seams with your feet so I believe we're good. I don't like the way it looks. So, I'm going to drain it over the winter and use a good tarp over the foam board. I think that will fix it. I hope this helps. I would love to know how it goes and what you do. The pool company also sold us a wall foam. I almost didn't get it I'm so glad I did. It's 1/6 " thick and when you run your hand down the wall it feels soft. They said to use spay adhesive to install it. That sucked the best way is to just use duck tape to hold it up...BTW we had a pool party today with about 10 kids/adults in the pool and the floor held up just fine.
 
Re: Polystyrene Foam Insulation for Pool Bottom - Pink Vs. B

Linen, Twelkner and Bradathins: thank you so much for your helpful responses. We had already purchased the foam when I saw your replies. We got the white 1" expanded foam. Home Depot didn't have the blue or pink foam in stock. Sounds like the same stuff you used, Twelkner. Thank you for sharing your problem with the liner falling between the seams. How do you think this happened? Do you think the tape failed to stick or did you leave some seams un-taped? We bought Gorilla tape too. After reading about your problem, I checked the reviews on it. Many people reported that Gorilla tape is the best duct tape on the market so that is good to know.

I have seen some pool people recommend the white foam online so it must not be too bad. However, I didn't want to use it after reading that it absorbs water and becomes mushy over time. I found that the closest Home Depot in southern California that carries the pink form is an hour away (Anaheim (Pullman St. store). We decided to make the trek and exchanged the white for the pink. I chose the half inch thick because the 2" was way too expensive (almost $29 per sheet). It does seem stronger so I hope it was worth the trouble.

I have a few more questions about installing the foam. I thought that we could cut paper templates by laying the paper over the frame before we put up the walls. My husband doesn't want to do it that way because he thinks the shape of the frame will change when the wall is installed. Does anyone have a suggestion on how to cut the curves accurately?

We plan to tape the seams on the driveway before setting the foam into the pool. Should we tape only the top of the seams or the bottom too? Tape the cove to the foam bottom? If so, is it necessary to tape one continuous seam along the bottom of the cove or just put pieces of tape here and there from the top of the cove down onto the foam floor? I don't want to waste expensive tape but we also want to do it right the first time.

I checked the prices of tarps to put on top of the foam. A tarp that is over 30 feet long would cost over $100 at Home Depot. We can't afford that so I hope the seams will hold.
 
Re: Polystyrene Foam Insulation for Pool Bottom - Pink Vs. B

Hey -

My only suggestion for the cutting is to get it as close as practically possible to the pool walls.

The manual on my pool was quite vague, and I've ended up with a lip between the foam -> crusher dust -> wall. Not a big deal, collects dirt.

Same with the seams between the foam pieces. I suggest putting 2 or 3 layers of duct tape. Either way I think you'll get seams/lips between the foam. We even used shiplap (overlaping) foam and still have it. Really it's not a big deal, other then it collects dirt.

Brad
 
Re: Polystyrene Foam Insulation for Pool Bottom - Pink Vs. B

When I bought our pool the pool company sold me a 1/4 thick foam pad to put on the bottom. That was before someone told about put foam board down. Since I bought it I used it. I laid it first after the wall was up. Used the pad cuttings for a templates. It worked. But, of course it wasn't perfect. I too, bought the foam cove, it cover it well. I didn't tape the cove it had adhesive on the back that work great. As for the middle of the pool I don't think you can stop the seams from showing; I fitted the board tight. If your not going with a tarp Then I would triple the tape. I don't know about putting the floor the together and then putting it. A 15x30 would seem to be hard to handle.
 
Re: Polystyrene Foam Insulation for Pool Bottom - Pink Vs. B

Thank you Bradathins and Twelkner. I bought three rolls of tape. I guess I'd better get some more. Since the seams tend to separate I think I will follow your advice and stagger the seams to minimize this problem. Did you put all of the tape on the top - none on the bottom?
 
Re: Polystyrene Foam Insulation for Pool Bottom - Pink Vs. B

I wonder if you could find a glue that is safe for use with that foam. Gluing the seams and then taping them would offer greater peace of mind to me. I also might choose the aluminum duct tape rather than the Gorilla tape since this will be much thinner and less likely to bunch up if carefully applied. Perhaps a layer of each would be best?
 

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Re: Polystyrene Foam Insulation for Pool Bottom - Pink Vs. B

UnderWaterVanya, thank you for your suggestion to glue the seams. I think that might be a great way to solve the problem. I called Owens-Corning to ask what type of glue to use. They said that there are many types that will work. They said to avoid petroleum-based glues as these will melt foam. I guess it is a matter of reading the applications on the label. Some types of all purpose construction glue were mentioned. I did a Google search and found that some people like to use Elmer's spray adhesive. I guess I'll check at Home Depot to see what I can find. I'm not sure how the aluminum tape would hold up. It would probably be strong but I would be afraid to try it since I've never heard of anyone using it for this purpose.

Twelkner, thank you for your reply. I would think that taping the top would be sufficient but since you had a an issue with the seams, maybe we'll use at least some tape on the bottom as well. I'll let you know how it works out. The frame is set and we're now sifting dirt to make the base under the foam. I had hoped to finally put water in the pool this weekend but we're attending a wedding on Saturday so it might take a bit longer. Fortunately, it usually doesn't start to cool off here until mid to late October.
 
Re: Polystyrene Foam Insulation for Pool Bottom - Pink Vs. B

Kendog2, my wife made a suggestion. While taping the seams vertical you may want to also use small pieces horizontal to the seam. You could space them out. Don't know if it will improve it or not. Just a thought.
 
Re: Polystyrene Foam Insulation for Pool Bottom - Pink Vs. B

This is the type of glue you should use on your seams, if you bought shiplap. Honestly though, I don't think it'll make a difference, it'll just mean those pieces will stay together. Your pieces shouldn't be moving apart (ie away from each other), but possibly up/down due to different compactness of the underlay.

http://www.homedepot.ca/product/pl-300- ... 0ml/972908
 
Re: Polystyrene Foam Insulation for Pool Bottom - Pink Vs. B

Thank you Twelkner. I like your wife's idea.
Bradathins, Thank you for sending the link for the Lepage P-300 glue. Unfortunately, Lepage products are available in Canada only. I'm a Canadian but I live in California. The glue we bought is Loctite Premium Construction Adhesive. Our foam isn't tongue and groove. It has flat edges.
 
Re: Polystyrene Foam Insulation for Pool Bottom - Pink Vs. B

Yeah, wish she would have thought of it earlier. Keep us informed how it goes. That way when I redo ours I will know what works....
 
Re: Polystyrene Foam Insulation for Pool Bottom - Pink Vs. B

Twelkner,

Ha ha. That's why you married her, isn't it?

Well, we are finally ready to install the liner. Our liner was stored in our shed for a couple of years. When we opened the box, we discovered that the liner has been cut and is unusable. We have no idea how this happened. There is a hole in the box so perhaps something fell on it. We're going to have to spend another $200 for a new liner.

Question: Do you think it would be a good idea to cut and tape the damaged liner on top of the foam pad? Would it help to hide the seam grooves? Most of the seams are tight but not all are perfect. I thought I read somewhere that it was a bad idea to use a tarp under the liner because moisture could become trapped between the layers and cause mold. Any thoughts?

I'll post another update soon about how the foam installation went.
 
Re: Polystyrene Foam Insulation for Pool Bottom - Pink Vs. B

That would be my same thought. But, I know someone that used a tarp and has said nothing about seeing discolor in their liner. A liner may not be able to breath the same as a tarp.
 

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