Name of compound/sealant for foam next to concrete?

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I have the same foam between coping and deck. So do you dig out the foam and then "caulk" it? My pool has only been up a few months but it looks like the foam is going to degrade pretty fast on top. The roll of foam looked to be about 3 inches wide


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jagger2005 said:
I have the same foam between coping and deck. So do you dig out the foam and then "caulk" it? My pool has only been up a few months but it looks like the foam is going to degrade pretty fast on top. The roll of foam looked to be about 3 inches wide


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Click to expand...

I had someone just do this and he used Sikaflex. He told me he cut the foam donut want as high up ) but I didn't see him do it)
 
I think there are two afferent things you're talking about.

When the deck is poured they put down an strip of polyethylene foam which separates the concrete from the coping. That is the expansion strip. It's usually perforated about 1/2" deep so after the concrete is cured, you can grab it and pull up on it. It will tear at the 1/2 deep perforation and you'll end up with a groove that is meant to be filled with the sealants already mentioned.

As an alternative, sometimes the entire expansion sheet is pulled out of the ground and replaced with a material called Backer Rod. Backer rod is set in the expansion groove and covered with sealant. Backer rod is also a polyethylene foam product, available in various diameters. You use it so you don't have to waste tons of sealant to fill a deep expansion gap. It's better to have a shallow bridge of sealant than a very deep section of sealant.
 
gtemkin said:
I think there are two afferent things you're talking about.

When the deck is poured they put down an strip of polyethylene foam which separates the concrete from the coping. That is the expansion strip. It's usually perforated about 1/2" deep so after the concrete is cured, you can grab it and pull up on it. It will tear at the 1/2 deep perforation and you'll end up with a groove that is meant to be filled with the sealants already mentioned.
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HaHa. You described it so much better than I did. This is exactly what I have. I did not realize it was perforated. My PB just left it as is. So the deck was poured about 10 weeks ago. I assume this is a task that could easily wait until fall/spring (no real winter here in SA)?
 
I did sikaflex myself and it was pretty easy. Home depot sells it in either gray or tan in the large size caulking tubes. It's approx 11 dollars per tube and I only needed 3 tubes so it was really cheap to take on as a diy project. It's self leveling, so you just squeeze out enough to fill the crack and it does the rest for you. You can finish it with sand, or leave smooth.
 

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I wonder if the Sikaflex will hold up to Salt/Chlorine as well as the Deck-O-Seal.

We are at the stage of needing ours sealed, and I can't find anyone to do it for us. So that leaves it up to me. What I read is the Deck-O-Seal 2 part is supposed to hold up to Chlorine better???

Seems like the One Part Deck-O-Seal product is just like the Sikaflex???
 
Deck-O-Seal is a PolySulphide Rubber material known outside the pool industry as Thiokol, after the company that popularized it's use after WWII. It's commonly used as a sealant in aerospace because it has good fuel resistance but it's somewhat pricey.

Sikaflex is a one part Polyurethane based material. There's several different grades but the self leveling kind is what you want for easily producing a good surface appearance.

I've had my joints filled with Sikaflex for 3 years and it looks pretty much the way it did 3 years ago. I was initially concerned because there was mention in a data sheet that constant contact with chlorinated water should be avoided, but I haven't seen any problems and they must provide that warning for folks who are using the stuff for building fountains and the like.
 
jagger2005 said:
HaHa. You described it so much better than I did. This is exactly what I have. I did not realize it was perforated. My PB just left it as is. So the deck was poured about 10 weeks ago. I assume this is a task that could easily wait until fall/spring (no real winter here in SA)?
Click to expand...

You builder may or may not have used the "tear-off" perforated (or partially cut through) style. If he didn't, you may have to pull the entire strip out and replace it with the Backer Rod cord which is fairly easy to do. Home Depots in my area sell one size of Backer Rod. Concrete and Masonry suppliers have a wider selection of sizes.

Ideally you want to push the Backer rod down so the depth you have to fill is roughly equal to the width of the groove. By sizing the sealer cavity that way, the cured sealer will be able to stretch and compress as slight movements occur, without un-bonding itself from the concrete or the coping.
 
gtemkin said:
Deck-O-Seal is a PolySulphide Rubber material known outside the pool industry as Thiokol, after the company that popularized it's use after WWII. It's commonly used as a sealant in aerospace because it has good fuel resistance but it's somewhat pricey.

Sikaflex is a one part Polyurethane based material. There's several different grades but the self leveling kind is what you want for easily producing a good surface appearance.

I've had my joints filled with Sikaflex for 3 years and it looks pretty much the way it did 3 years ago. I was initially concerned because there was mention in a data sheet that constant contact with chlorinated water should be avoided, but I haven't seen any problems and they must provide that warning for folks who are using the stuff for building fountains and the like.
Click to expand...

Thanks for the info above. I am leaning towards the Sikaflex, but still toying with trying to find someone to do the Deck-O-Seal for me - $800 was one quote I had months ago from a different decking contractor than the one we selected.

I wonder if the foam that is down inside the gap is OK to caulk over, or do I need to push it down further and put backer rod in the gap instead? Seems like the existing foam would be a good base for the Sikaflex?
 
santacruzpool said:
Thanks for the info above. I am leaning towards the Sikaflex, but still toying with trying to find someone to do the Deck-O-Seal for me - $800 was one quote I had months ago from a different decking contractor than the one we selected.

I wonder if the foam that is down inside the gap is OK to caulk over, or do I need to push it down further and put backer rod in the gap instead? Seems like the existing foam would be a good base for the Sikaflex?
Click to expand...

Foam is fine for sikaflex. You want about 1/4-1/2" depth

I think if you do it yourself you'll be glad you saved the 800 bucks. It doesn't take but a few hours and isn't very difficult.

Also, if you happen to drip some on an unwanted area, it's easiest to let it dry and then scrape off once it's dry. If you try wiping it, you'll just smear it.
 
It would probably be OK but like you said, it needs to be pushed down or removed and replaced with backer rod that positioned to give you a thickness of sealant approximately the width of the expansion gap. I would not lay a bead right on top of it the way it's positioned now because the sealant will be too thin and it will crack and split easily.
 
Alright Jagger - we are in the same boat here! My perforated foam has been pulled off, and I cleaned up the gap pretty good, just needs a good vacuum and blow off to get it ready I expect.

You ready to tackle this on your own? I am slowly getting there...

- - - Updated - - -

Alright Jagger - we are in the same boat here! My perforated foam has been pulled off, and I cleaned up the gap pretty good, just needs a good vacuum and blow off to get it ready I expect.

You ready to tackle this on your own? I am slowly getting there...

---

Thanks for letting me Hijack your thread a little
 
I was finally able to get this project done last weekend.

I had previously bought 2 tubes of the Grey Sikaflex, 3 rolls of green concrete masking tape, and a large caulk gun at Home Depot.

On Saturday I started the taping of just one side of our pool, and once I started squirting the caulk in I quickly used one tube in about 25 ft. So I knew I would need more to finish my project. I decided to do one side only first to see how things went, and then go from there.

Once I had the first side all filled in I decided to start adding sand to the surface to make it look like grout. The sand I had on hand looked awful sprinkled on the surface. I was sprinkling it out of a plastic bag with a little hole, which made it impossible to get an even coating.

I resorted to going back to my original plan of concrete drilling a leftover blob of dark concrete I had saved just for this project. This made me a nice amount of dark grey magic dust. I then tried using the plastic bag method again, but it still was really hard to make it look even. I needed a shaker - so I grabbed an old jelly jar and drilled the top with a series of 1/16" holes to be my new concrete dust shaker. I found that the dust/sand would sink into the Sikaflex a bit, and get a little darker - so my method involved a light shake first, and then following up with a bit more dust one or two more times to get rid of the shiny surface and make it more uniform. I blew excess off at the end and touched up areas that looked light or needed more.

Below is a section of the finished product. I got pretty sore crawling around and slowly pouring out the caulk, and shaking on my magic concrete dust - however all in all it looks just like my coping grout. If it lasts a long time it will be worth it. One section I did in the heat of the day, and added a bit too much dust, so it cured a little less than perfectly flat in a few areas...

IMG_20150927_155234059_HDR%25255B1%25255D.jpg


We are now officially done with the pool - we made our final payment to the pool company Wednesday after all the punch list items were complete!
 

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