Replacing caulk in expansion joints

[botanica37]

I have to replace the caulk around the whole pool. It was done by a pro 2 years ago and is completely cracked in lot of places, separating off the concrete and the pool. When I pulled some of it off, the foam was wet underneath, so obviously it is not doing its job. I have couple of questions:

1. In some places the old caulk is coming out very easy, but there are couple of spots that it is nearly impossible to remove. That makes me wonder if there is some factor during installation that makes it stick better?

2. There is a gap between the foam backer and the concrete/pool. I've been reading that the backer should be wider than the hole - is than an issue?

3. I used a can of Sikaflex SL (self leveling) and I suck at caulking I would honestly would have hired someone if the previous caulk didn't fail after 2 years...But now that it did, I am hesitant that a pro will necessary do a better job than me. At close inspection the old caulking was not as perfect as I would have liked either. I tried taping around the perimeter and that didn't work too well either. Any advice on how to do this?

4. How far over the joint should the caulk go: just fill the gap or spill over to ensure seal with both surfaces?

Thanks for any advice!

 

[geekgranny]

Same situation here although my caulk job by a pro has lasted a lot longer than yours. I just can't afford to pay someone to do it now.

Not meaning to hijack your question I would like to add another question, if I may.

Does all of the old caulk have to be removed if in places where it is still serving its function?

geekgranny

 

[reindeerboy]

I am by no means a professional at caulking, but I just did mine around the pool. I took a knife and some other tools and cleaned out any and all old caulking that would come out as best I could.

Then I took a shop vac and sucked up any debris, dirt, or whatever was in there.

Then I took some bathroom 100% silicon caulking. White in color because my coping is white and I then went to work. After I laid some down, I ran my finger along it to make it level and smooth against the gap between the concrete and the pool caulking.

Here is a pic that I attached to help you get a better idea of what it looks like. Oh yea, I then repainted the aluminum pool caulking with rustoleom white paint after the caulking dried.

Looks great I think anyway.

Good luck.

 

[Guest]

OK, first post. Been lurking around for months but felt the need to respond and try and help.

The Sikaflex SL is a great product, and works well in the caulking gun application. I'll expand a bit on reindeerboy's post:

Go to the hardware store (Home Depot, Lowes, etc.) and get a carpet knife. They are the hooked ones that the carpet guys use, and they work great for cutting out the old mastic. Cut down the deck side and the coping side of the pool and it should pull out pretty cleanly. ShopVac out the joint, and get some silica sand to pour in the joint area (a cup works well for pouring the sand). Put in enough sand so that you have a half an inch of area to fill in with the Sikaflex material. Sometimes there will be ant holes or the like that will allow alot of sand to go down; don't worry, just keep filling! You can smooth the sand with your finger to get it at the half inch point. Now cut the tip of the Sikaflex and put the tube in your caulking gun (probably have to buy one 'cuz they are so big!) and start at one end of the pool, working your way away from the starting point. The material will flow out and self level, so just keep moving at a rate that allows for it to flow out. When you are all done, take some more of the silica sand and sprinkle it generously on the new joint. That will make the new joint look more like a grout joint than a shiny plastic joint! After 24 hours or so, vacuum up the extra sand and admire your work!

Hope that helps!

Bruce

 

[botanica37]

Thank you, Bruce. There are couple of places that the caulk just won't come out...it feels wet and soft, like a putty. :grrrr: But since it is white and the SL is gray, it has to come out. I am off to HD for that carpet knife - hope it will help. I will post pics as soon I am done.

 

[geekgranny]

OK, first post. Been lurking around for months but felt the need to respond and try and help.

The Sikaflex SL is a great product, and works well in the caulking gun application. I'll expand a bit on reindeerboy's post:

Go to the hardware store (Home Depot, Lowes, etc.) and get a carpet knife. They are the hooked ones that the carpet guys use, and they work great for cutting out the old mastic. Cut down the deck side and the coping side of the pool and it should pull out pretty cleanly. ShopVac out the joint, and get some silica sand to pour in the joint area (a cup works well for pouring the sand). Put in enough sand so that you have a half an inch of area to fill in with the Sikaflex material. Sometimes there will be ant holes or the like that will allow alot of sand to go down; don't worry, just keep filling!

Hope that helps!

Bruce

Thanks much bruce for such clear and direct instructions. Couple of questions. I asked earlier about removing all of old. Al lot of my caulk is still in good shape, doing its job and looks good. Due to our shifting, unstable ground, concrete moves around and shifts all directions. Thanks goodness this was apparently taken into consideration when the house pad was poured in '74. But concrete walks, driveways, etc., new and old, all around this area crack and shift. It is a big problem with newer house foundations in the area where the builders didn't account for our (sub) and terrain. When I approached the retired, pool guy for instructions on how to do it he suggested that it was a job I didn't want to tackle, that is removing the old caulk, and he offered to do it for a good price. Beautiful job too.

Half of my pool is supported with (what the previous owners told me) pier and beam, fill, and soil, on the side of our close-to-the-house hill. Soon after we moved here I added railroad ties and more fill for support but things still shift. At least we don't have to worry about the pool floating up when it is empty. :lol: I jokingly tell people that our steel pier and beam deck is what keeps the house from sliding down the hill. I'm not totally joking though.

The coping is bricks with rolled edges; decking is cool decking on top of concrete. Decking has one crack at deep end, running from coping to edge of decking, that was here when we moved in '86. It has widened a bit but tolerable. The space between the coping and decking ranges from 1/2" to 1 1/4". There is a bit of vertical shifting where the edges are not level. This has been this way forever and only shifts a little each year. Pool has never cracked though but did have a leak fixed, years ago, near deep end that was caused by a cracked pipe under the deck. I couldn't detect any extra moisture down drop off or bottom of drop off. Detection guy had to use sounding equipment to find the leak. He figured it was caused by shifting putting stress on pipe. I think it was at a bend in pipe.

Question: I'm afeard that it might take huge amounts of sand to fill the spaces. The space might be "bottomless". Nothing surprises me out here. Wouldn't rolled foam help especially if it was larger than space and wedged well in? I have used foam around here (our house) for lots of repair/fix up jobs. I'm pretty sure the two guys who did the last job, a very nice one, used enormous amount of sand.
Thanks, geekgranny=alice

 

[Guest]

Alice-

I don't see why the foam wouldn't work (maybe in combo with the sand). Sand is just easy to level, which is why I use it. Sand is pretty cheap, so I wouldn't worry too much about that (unless you're putting in truckloads and it ain't stopping!).

I don't think the Sikaflex is made to do an 1 1/4" wide joint, but I'm not sure why it wouldn't work either. I guess you could give it a try and see how it holds up!

I'd replace all of your joint at the same time, just so it looks nice and uniform. You know the rest will go bad eventually and you'll have to do it anyway!

Let us know how you did :-D

Bruce

 

[duraleigh]

I like Bruce's idea of the sand. It's possible there are some significant voids under there and the sand will, to a limited extent, help fill them.

The polyfoam rope is called "backer rod" and is available at HD/Low's in limited sizes and in many sizes if you can find a trade supply house that specializes in concrete

 

[botanica37]

To continue on my previous post, I just checked the caulking I did last fall (Sikaflex) and on a lot of places it has come out from the joints. I am wondering if that is installation error (me doing something wrong) or something else? Should I attempt to replace it again myself or call the pool guys?

 

[Guest]

If it was tight before you closed up, and it is separating now, then you have movement. The first picture is pretty blurry, but it looks like the deck is moving away from the pool in that area (hard to tell with little to see). The second picture looks like it is all in place still (and it looks like you did a good job!).

Pool guy will charge more than the cost of if you do it yourself of course, and if you have movement then the same situation will occur. I don't think it is the Sikaflex or your work, from what I can see.

 

[cobra46]

Can you retake the pictures using the macro function? The button or setting will have a picture of a little flower. It allows the camera to focus at much closer distances than the standard setting.

 

[botanica37]

here are the new pictures, with the close-up looks pretty depressing. All "detached" caulking is at the pool side not the deck. There is definitely movement, just not sure why. The pool and the deck are at least 10 yo.

 

[Guest]

The caulking is "detaching" from the pool side because the deck is moving away from the pool. You either have a slope on that side or there is expansive soil. Pools don't usually move, but decks often do!

 

[kevreh]

This is probably too late, but....

The pros who re-caulked around my pool used a two-part mixture that they then put in what looked like a masons bag to squize it out. Stuff was really smelly. Thing they did that you didn't mention was after cutting out the old caulk, they went around the pool with a wire-brush-wheel on a drill to roughen and prepare the insides where the caulk will adhere. I think this was important in order to etch the concrete and really give something for the caulking to grab.

Also, they did use tape, might have been more heavy duty like duct tape. They also pulled ALL caulk out, good and bad. This made for a better and more consistent job IMHO.

Lastly, good point about the deck. It needs to be stable. I had mine pumped (drilled holes, pumped with limestone concrete mixture) the year before.

Paid like $300.

Regards-
Kevin

 

[glindleyiv]

I found the info in this discussion very useful and recently caulked around my pool using gray Sikaflex self-leveling caulk. Thought I'd share some additional comments. My pool is only a few years old and had not been caulked before, just had the foam barrier which was beginning to deteriorate. But my coping and the adjacent cement were fairly even all the way around, so self-leveling seemed to be the way to go. I removed the foam barrier as it was no longer tightly in place, replaced with 3/8" backer foam. In retrospect, I should have got some additional wider backer foam as there were a few places it ended up being somewhat loose and some of caulk went past.

It turned out to be much easier than I thought it would be, biggest pain was putting painters tape all the way around on both sides. I highly recommend this, picture the thick gray paint used for garage floors and it gives you an idea of what the Sikaflex is like. Running over the sides isn't the problem as it flows well and you just keep moving. Its more about having a place to put the nozzle when you need to go back or shift your position. It is messy if you get in on the cement, but comes off the coping easily. It went quickly and I was happy with the results. Sprinkled sand over top and I think it blended in nicely with the coping and cement. Used 6 30oz canisters and 3 10 oz canisters to do 110 linear feet. Ended up spending about $120 on materials, versus $700 lowest estimate to have it professionally done.

Do yourself a favor and spend the extra 10 bucks for a good caulking gun. It is easy to take breaks, just put a small piece of the foam backer where you stop to keep the caulk from continuing to flow, I basically did one tube at a time

 

[kevreh]

Good idea sprinkling some sand on the fresh caulking. Wonder how well it will stay there? (versus washing away with time)

 

[txconcrete]

a great tool to remove old caulk is a multi-function tool, you can pick one up at northern tool or harbor freight for about $25.00. you can get them at the big box stores too but it's quite a bit more pricey. it's a tool that vibrates instead of sawing and if one of the blades you can get has little teeth on the end that cuts the old caulk right out. also for those areas where the caulk won't come off, a metal brush or an angle grinder with a diamond blade will clean up the side walls so that the next round of caulk will adhere properly to the walls. it's a good investment because you really can find it useful around the house to do all kinds of stuff.

there is another solution too for your expansion joints. I find it only works on the pool deck expansion joints, and not the coping. it's a rubber product called gap armour. they only have big sizes so the coping is usually too small a space for their product to fit, but it works pretty nicely for the joints because you don't need to worry about adhesion or the mess of caulk. the other prodlem is you have to order direct as they don't have too many retailers (if any) that resell for them, but it is a product that requires very little thinking I have just popped it into the joint with a rubber hammer.