Most of the gunite builders in my area leave the foam. Sometimes they come back a year later and seal it, sometime they don't.

The fellow giving the estimate is correct in that it needs to be done. When I do it, it's usually about $12 a foot, depending on how much prep work is needed. The self leveling compound used is not cheap and there is often a substantial amount of labor prepping, most of it on one's knees. This is where most of the job costs are.

Scott

Scott

Does it still need to be done if the decking are pavers? I was told that there is enough play in them to take care of the expansion.

Usually pavers don't have an expansion joint. Ever seen expansion joints on a large paver deck? I haven't.

Scott

You're missing one thing. There is a difference between expansion allowance and protection of the sub-surface that the deck sits upon. Expansion joints exist to allow the inevitable shift in order to prevent damage to the opposing edges. In this case, cracking bond beams, tile concrete deck, etc. The joint exists for this reason. Now you have the joint, you can't ignore the next step to prevent the inevitable. That is sub-surface erosion. Leaving the joint open allows water to get under the deck and if your deck was graded properly, it is at a slight pitch away from the pool. Water, whether it is pool water, rain, irrigation or whatever, goes down and out. It will channel the sub surface and create voids and then lead to sinking decks and cracking. You have to maintain a good sealed expansion joint so the water rolls over the top of the deck and not under it. Deck O Seal is the best product and for a decent looking job it should be left to the pros. Costs vary but it is a minimu of $6.00/ft for a decent job. Doing it wrong or not he cheap will only cost more.

The foam like material is called poly-void and it's probably 1/2" thick by 4" wide. It should have been precut approx. 1/2" from the top so that the uppermost portion of the foam can be peeled back leaving a 1/2" by 1/2" gap to receive your expansion material. Deck-O-Seal is commonly used but I like Soudaseal SL (self-leveling) it is used on high-end applcations and also comes in soudaseal FC for vertical applications where SL does not work. repair_guy is right, this is a very important expansion joint between the coping and the deck and sould be watertight to prevent water from getting under the deck, under the shell and underneath the coping. The cost in my area is $4 - $6 per foot.

I have pavers and they did leave a 1/2 inch expansion joint between coping and pavers. I have the foam inbetween, but instead of putting the caulk on top, I went with the polymeric sand which gets real hard, hope that helps

Poolguynj - If this is so vital, why are pool companies not required to address this? I am very angry that a brand new pool was delivered with this ineffective and potentially damaging expansion joint material. I will be contacting my pool company first thing Monday about this.

I encountered the same situation in Northern VA. The foam stuck up above the elevation of the deck and looked like crap. I called and said, "You're not really going to leave it like this, are you?" I was told that the caulk application was usually an added expense (that I was never made aware of), but they would come out and do it "as a favor" and it wasn't typically part of the pool build. They took care of the caulk, but I wasn't happy that I had to ask about it and they were just going to leave the foam sticking up above the coping and deck.

Pat,
I thought this was put to bed after we touched base a few weeks back.... As I said the foam properly taken care of could/will last for years. I can show you pools in your area 5-7 years old with the foam still intact. To add mastic on a new pool would create yet another trip after the fact because the deck should be given time to settle. Mastic joints are very popular on renovated pools because the deck is not ripped out usually and the "GAP" is larger so the mastic fills it in more evenly. I've built hundreds of pools with BHP and have never used mastic joint. It sounds as though the cover company was trying to scare the hell out of you to make $1600. If you truly want to install it , I will discount it down to my cost for you.... Thanks

The foam used is a gating factor. I have seen two type, a small cell foam and a large cell. The small cell foam tends to last longer as it absorbs and holds far less water and dirt. The large deteriorates on the exposed surface after a couple years due to exposure.

Trimming it down the 1/2" or so after the deterioration is evident and pouring the self leveling compound seals and protects it but isn't needed immediately. The newer pool and deck may settle.

If settlement has opened a space where the foam is loose and water can easily penetrate, it should be sealed. If it's tight and not deteriorated, leave it for now as top50 suggests.

Nice to see you back tfb. Hope your year has been a good one.

Scott

Thanks Scott, as always busy... hope all is well... Pat please post some pics I would love to see the finished pool. :)

Poly void is not a sealant. If you are putting in a concrete deck around a pool. You then must put mastic or in my case I install Deck o seal in the joint to keep the water from going under the deck and eroding the ground under the deck. I realize there are many pool builders that do not do this but it needs to be done to protect your decking.

Man I hate seeing builders take short cuts.

What ground under the deck are you eroding?.... the concrete is on a minimum of 4" of crushed stone... that close to the beam could be as much as 10"-12" ... by the ramp 18" or more.... the compressed foam will hold up for years... even in the north east..... I do over a million a year in reno work... I've seen 25 year old pools that had a FELT expansion joint with perfect deck on the pool... that felt disappeared after a year or two.... I don't use thin set on tile or coping...I don't build junk..... I warranty the pool, if it was that big of a concern ..don't you think I would prevent a problem before it happens?.... Sounds like the cover guy thought if he scared the HO enough he would bite.... $16.00 a foot is crazy... its almost double what it should be....

The only thing that I will agree on with you is that $16.00 per LF is very high. $6 to $8 Per LF is more like what it should be. Not putting a sealant in the joint between the coping and the concrete deck is a short cut. I realize the company you work for is not big on quaility but trust me in this there are alot of quaility pool builders like myself that insist on building pools correctly.

Fighting Irish,
My parents have a pool that is 43 years old and in great shape. It has never had sealant, and I don't think it ever had foam either. They live in the NE.
And what about decks made from pavers? There is no sealant required for them. Why is it so important to have a sealant on some decking and not others?
Decking is always sloped away from the pool, so it is not like the gap is accepting a ton of water anyhow. My paver decking around my pool is built to let water drain through, so what is the big deal?

I dont mean to pick on you, but I can't help myself.... a properly done deck coping edge should have about a 1/4"' gap or less... no more than a saw cut in stamped concrete.. which doesn't get mastic.... in the winter months the pool cover, covers the coping edge.... so there is no infiltration during the winter months... once that foam disappears in 5-7 years ... yeah it would be a good idea to replace it with mastic... As far as the quality comment, I personally build pools for people for who can afford to build with anyone.... maybe even a clown like you... my phone number is all over this forum , your welcome to call to discuss your comment. There are a lot of good builders on this forum that I have freinded, If you want to talk crap , move on... or be constrcutive with your comments.

Not sure if this is what you want but I would try this before throwing down $1600. Wacth the video at the bottom.

Here is a link that might be useful: Santastic Pool Mastic the Alternative to Deck-o-Seal

Concretehole,
That stuff looks pretty good, but if it is so green and non toxic, why is the applicator wearing rubber gloves?

I had to address this. topfiftybuilder, I have attached a link to a document that you should review. It is from the ICPI. It's what a legal expert in failure determination would use against you to prove that you are not complying with established protocols provided by a leading industry institute in this arena. It calls for the foam backer rod with a neoprene or urethane sealant. Do what you will but it only takes one significant failure in the beam of your structures to make you feel sick. Best of luck!

Here is a link that might be useful: ICPI

This diagram shows foam and sealant with a paver deck. Is it true that even a paver deck needs foam and sealant? And if not, what is the difference between a paver deck and a concrete deck that makes a difference? I have seen many pools w/o sealant.

Mr DIY, I think everyone appreciates you coming out of Garden Web retirement to respond to this thread. The diagram shown is a paver patio on top of a concrete sub base, neither of which this thread is about... I'm sure this was an over site on your part... Thanks

2 questions about my current job with a pool remodel that came with a pool contractor selected by the Owner. (only 2 were available in a 100 mile radius and this one seems a little too seat of the pants for my liking)We're installing a new Pavestone paver deck over a concrete slab after demolishing the bond beam and the concrete deck 2 feet away from the pool. New bond beam was installed and waterproofed properly. Slab was installed by my crew using 1/2 thick bond breaker against the new bond beam. I had my crew put 6mil poly over the entire slab, adhered to the edge of sandstone flagstone coping and the 1st 6" of new slab with a 12" strip of Vycor. The new 90 degree expansion joint between the bond beam and the slab received backer rod and bitumen mastic before the Vycor strip was installed. This will completely prevent any water getting into the bond beam, slab subgrade, or the setting material of the coping stones, however, there seems to be some disagreement on what kind of gap is required between the coping and the pavers, if any. Any recommendations? Also the pool contractor used natural coping stone of varying thicknesses. What would be the maximum tolerable joint between the bottom of the stones and the top of the waterline tile? If it were me, I would pick the high spot and cut all the remaining tiles within 1/4 " and strive for a maximum 3/8" caulk joint. What is acceptable industry maximum?

Pavers already move with temperature changes so it doesn't need an expansion joint but if there is a slab below, it needs to be separate from the shell with a membrane to allow for the shell and slab to expand and contract separately.

Sandstone, IMHO, is not an acceptable coping material. It is too soft and porous.

Coping is mortared to the top of a bond beam. A coat of Thoroseal can be added to the top and 1st 6" inside the beam to waterproof this section so that it isn't deteriorated by the water over time.

Scott

Txs, Scott. Got the slab to pool wall separation covered. Agree with the unsuitability of sandstone coping but it's being used a lot here in Colorado. I made the pool contractor provide separate warranty to Owner. What is your opinion about the maximum acceptable size of the joint between bottom of coping and waterline tile, given coping is natural stone with bottom edge quite uneven?

Well, since I wouldn't use it, I can't say.

Scott

I would recommend that you use Tremco Vulkem SSL. This stuff works, is flexible and lasts (perfect for California, where we tend to have little tremors). I have provided a link for your convenience.

Here is a link that might be useful: Tremco Vulkem 45SSL

This post was edited by rjagodka on Thu, Feb 21, 13 at 18:26

concrete guy put concrete btw the brick and now pool company doesnt give the warranty.

any suggestion

I am currently having my pool renovated. We went from a concrete pool deck to a pavered one. I had problems with the concrete cracking and sinking and after 20 years decided I was done with concrete. My question is the spacing that was used between the pool coping (a concrete paver cap) and the pavers around the coping on the pool deck is 1 to 1 & 1/4inches. They are using polymeric sand and the space seems much wider than I had envisioned it. Is this an acceptable space or should it be narrower? Also the paver cuts around the entire pool decking near the coping is not all uniform. Shouldn't a good mason make sure the cuts are all uniform and even. I hate sloppy work and am a bit of a perfectionist. They are hopefully coming back tomorrow and correct these and other issues. Any comments/suggestions would be much appreciated.