Caulk between deck and coping?

[bhelme]

My pool "chemical seller" company says I need to replace the closed cell foam between the deck and coping with caulk. My builder said nothing about that. Do I need to do it?

[duraleigh]

Hi, Brian,

Give me a little more info. Be very specific where it's located. How much of it? Does it extend all the way around? What surface do you see there now? How wide is the gap.

Most expansion joints (I'm sure that's what this is) are a combination of closed cell foam sealed on the visible surface with caulk. I'm a little confused when you say "replaced with":confused: :confused:

Dave S.

[bhelme]

Wow, you're hitting all my questions today aren't you?! Thanks.

Give me a little more info. Be very specific where it's located. How much of it? Does it extend all the way around? What surface do you see there now? How wide is the gap.

The foam runs the entire perimeter of the pool between the coping and the deck, "approx. 115 linear feet" (chemical seller's estimate). The gap is about 1/2" and the foam is about 3/8". I know when the deck was put in that the foam is about 4-6" high (whatever thickness the deck is). Currently the foam is level with the top of the deck and coping, not recessed.

Most expansion joints (I'm sure that's what this is) are a combination of closed cell foam sealed on the visible surface with caulk. I'm a little confused when you say "replaced with"

All the written quote says is "caulk the expansion joint", not what exactly they'll do. $684 sounds like a lot if all they're doing is capping off the top. Heck, even if I have to buy some specialty caulk and cut away some of the foam to get a decent layer I ought to be able to do it for a lot less. Do you think it's a DIY project?

[duraleigh]

Hi, again,Brian,

Yes, it's a DIY. That said, it's amazingly tedious and you must be VERY careful working with polyurethane caulk but it's actually quite rewarding and you can do an even better job than they because it's your pool.

1. You must "scrape" out the foam down about 1/4" at least and 1/2" is better. Resulting channel should be as deep as it is wide.

2. Next you need to somehow seal the space between the foam and the decking (or coping) if the foam doesn't reach from side to side. That could be tough to do. I'm thinking of finding some type of cheap plastic trim from home depot you could wedge in between the foam and the coping to get a tight fit. (you said gap is 1/2 and foam only 3/8, right)

3. You're ready to caulk. Polyurethane is the most durable you can use but it's not very forgiving....here's what I did. Carefully fill the channel just slightly overfull with a caulk gun. Be careful not to let much get out of the channel, it a bear to clean. (keep a rag with MEK solvent handy). Once you've caulked as carefully as you can, drag a 1" putty knife down the seam applying slight downward pressure. The caulk should compress into the channel slightly and then bulge the tiniest bit after the putty knife passes over it.

That's it! That little rounded bulge will flatten virtually level as the caulk dries.....be aware, 24 hours before you can touch it and days before it's completely cured. The result, however, is a magnificently durable, waterproof seal that will last for years.

I used a product called Vulkem 911 by Tremco. Found it at an industrial supply house for about $3.15 per tube, I think. It comes in lots of colors so you can match it with surroundings pretty well.

You might try a few feet and see if you want to tackle it. I had much less to do than you and it was quite time consuming. If you pay to have it done, I'd be pretty adamant about polyurethane caulk. It would be mighty easy to put acrylic in there and walk away. I don't believe it will hold up in that harsh environment. Let us know if you tackle it!!:) :)

Kelly, Ted, or one of the other pro builders may come along and offer a less labor intensive solution if you can be patient......they don't check in as often

Dave S.

[Lenny]

Dave is right on as always.

I have to do the same thing. I was suprised that my builder did not take care of this but it sounds like that's the norm. My install was done too late in the year to caulk. I tried but it was too cold and the caulk wouldn't flow well.

I'll look for Vulkem. I picked up several varieties from Home Depot and Lowe's and I'll try them out soon to see what works best. There are a few types that are meant for concrete expansion joints and they're supposed to look like concrete when they cure.

[sunofthebeach]

I did the same thing last season. The estimate got was $6 a foot so the $600 price you were quoted seem right.

I used this sonnebone NP1 caulk and the backer rod. There is also directions at the bottom of the page.

http://www.poolcenter.com/service_supplies_pool_caulking_supplies.htm

Don't order from this company if you decide on going with Sonneborn, though. If you find a dealer, you can get a 30 case of caulk for $100 and the backer rod is about $12 for 120 feet.

I would use the backer rod, It is just easier.


I used duct tape and put it on both edges of the gap around the entire perimeter of the pool, to keep the edges clean. then just caulk and remove the tape once the caulk is in place and shaped.

Also color is important. White is very unforgiving if you are a little sloppy about your work. It will look like crap it you are not very neat. I used a gray color to match the cement and it blends very well.

I would do a practice section to get the hang of it. When it dries, you can pull it out with a knife if you don't like it.

This job was pretty labor intensive, all told between scraping out the foam, putting in the backer rod preping and caulking, I bet it took me 10 hours.

[Tomcat]

The foam used for your expansion joint should already be scored to allow easy removal of the top 1/2" (at least mine was). But then again, if your builder was trying to save every penny, they may not have used expansion joint material made for pool installation.

I simply pulled mine out (the top scored section, that is) and used Deck-o-Seal to fill in the joint. It's expensive, but specifically made for pool use. You mix it and apply with a squeeze-type bottle. It's liquid and self-leveling, but very viscous. I'm sure other stuff (same compound) would work equally well.

Note that my deck was poured in the fall and I installed the Deck-o-seal the next fall after the deck had gone through one winter of freezing and heaving (recommended). It heaved quite a bit (over 1/2") but returned to normal. I still get quite a bit of heave and that has broken the bond between the deck-o-seal and the coping, but so far the deck has returned to normal height every year.

[dep78737]

I've heard you can sprinkle sand on the wet deck-o-seal to make it look less rubbery and blend into the decking/coping.

[duraleigh]

Hey, Brian

from "sunofthebeach"

I used duct tape and put it on both edges of the gap around the entire perimeter of the pool, to keep the edges clean. then just caulk and remove the tape once the caulk is in place and shaped.

Yeah, duct or masking tape is essential... I failed to mention that.

Dave S.

[bethsg]

We filled in the gap with the caulk. THe thing was, and we didn't think about it until after the fact... when the deck contractor poured the deck, he applied the foam around the perimiter of the coping. It had some sort of adhesive which kept it stuck to the coping while the concrete was being poured. When we removed it and used the caulk, we found after one season, the caulk seperated away from the coping. We believe this may have been due to the adhesive which was left on the coping when we removed the foam. So now we need to pull it out and do it again. So, how do you easily remove the caulk, and do it over.

[duraleigh]

Hi, Beth,

Did you use acrylic caulk? If so, that was probably the issue. As I indicated above, this Vulkem 911 polyurethane caulk was a complete hassle to work with but it doesn't shrink and forms what appears to be a very, very durable seal. Mine is 2.5 years old and looks like the week I put it down.

I wish I could give you advice on how to get the old caulk out....that's gonna be tough. I would do it mechanically...i.e. no chemicals.

Dave S.

[bethsg]

Dave,
We used SIKA Flex (Sikaflex-1CSL) polyurethane caulk, which my dh swears is the same as deck o seal. Its self leveling etc... it was very easy to install, using a caulk gun. But it took some muscles to squeeze it, but it did self level very nicely.
It didn't pull out everywhere just in some places, so I am wondering if we can just cut those piece out and redo only those sections...
The work never stops, we are opening our pool tomorrow.

[duraleigh]

Beth,

I thought poly would stick to just about anything but apparently not. That's a bummer it didn't hold up well. Patching it in seems like the best solution. Good luck with it.

Dave S.