Yes, he is correct. Your coping and your decking should be seperated by an expansion joint. Typically, the joint is fitted with a piece of foam that goes all the way down to the soil at the time of pour. Once the concrete is set, the foam is taken out and mastic is put in it's place. This seals the joint, but still allows each body of concrete to move seperately. I've seen pools that didn't have one, and the first sign is usually in the waterline tile. They will crack and sometimes just fall off.

Our coping and concrete deck is seperated by foam. I was under the impression that the foam would be removed and replaced with caulk. My PB just said "We can replace it but it costs $$". I feel bamboozled-it looks ugly w/ the foam half in and half out.

I would feel bamboozled to. It sounds like an incomplete job to me. I may be wrong, but I'm pretty sure that the joint should be sealed, typically with mastic. It's caulk like material and they usually cover it with sand. needs to dry for a couple days though. From what I understand, the seal is to keep mosture from getting underneath the slabs which could cause the soil to expand. Anyway, I would try and get him back out there and tell him to complete the job. Then again, if it wasn't listed in the contract, he might not be obligated.

Hi poolcrazy_2006,

does the foam stay in or is it removed to be caulked? After the caulking you are saying that it needs to be filled with sand? Or is the sand put in first then the caulking?
sorry for all the questions but this a lot of $$ spent.

thanks in advance,

~jv

Well it seems to be turning into an incomplete job. They were supposed to be here today to fire up the equipment now that the pool is filled but they never showed up. We discussed the issue again with the PB who now states he will charge $1 per linear foot to do the mastic-just a bit of nickel and diming. Oh well..I just want to swim!!

Our PB left the foam in however, they did shave it down 1/4 to 1/2 in. below the surface (not exactly sure) then they filled it with some sticky rubbery substance (probably mastic) then they spread a thin layer of sand on top which sticks to the sticky stuff (not sure why, maybe it just looks nicer) and it took a day or two to dry to the touch.

xnightowl summed it up pretty well. Doesn't really matter if they leave the foam in or not, but I would at least trim it down or move it. The important thing is that they are seperated and the joint is sealed.

I think any pool builder ought to do the mastic as part of the package when using coping other than a cantilevered concrete slab. It's just part of the deal, coping and mastic go hand-in-hand and should be sold together from the start.
$1 a foot isn't bad, though. Well, it's bad for the builder because he's not making any money at that rate.

Mastic was part of our pool package. They removed the top part of the foam (with some kind of flame torch thing), put in fine sand, then the mastic. He did tell me that it needs to be redone about every 5 years and should cost about $500 to do it.

Our PB told us today that he would do exactly that-flame torch, sand and caulk as part of our deal. Obviously the communication between he and his salesman failed.