Continuing Problem with cracking coping/decking

[Bill1974]

I am guessing when the decking was poured it attached in this area and with with the movement of the decking it's lifting the top corner of the pool and coping. The cracking in the skim coat is close to when the bottom of the deck pour is. The coping and the mortar used to attach it to the pool wall is stronger in tension than the concrete of the pool wall, it cracked at the weakest location. Fortunately it has not cracked though the wall. If it continues to be an issue cutting a relief between the deck pour and the pool wall should eliminate the issue and the coping and bond beam can be repaired for good. I don't think a regular rotary concrete saw will be able to cut that depth, you may need to find someone with the chainsaw type of concrete saw to cut deep enough to completely break the bond between the deck pour and pool. There should have been foam (or some other type of isolation barrier) on the pool wall before the deck was poured to create a slip joint. The ends of the rebar could have been bent and tied to the last row of rebar too.

 

[jcushman]

Thanks for your input.

There was a foam barrier between the edge of the coping and the deck pour. You can see that here:


Is that what you are talking about, or should there have been something additional?

Do you agree that the rebar from the pool wall bent and tied to the deck rebar is a problem and is likely contributing to the situation?

 

[jedigrover]

If I'm looking at that picture right, that foam is only covering the edge of the coping (it's a bond-breaker for the coping). My understanding is that your foam or black-board or whatever is being used to create the expansion joint must extend all the way down the entire thickness of the deck pour, to keep the deck from coming in contact with the beam of the pool. Not only should they not have tied in the rebar (should have cut it off flush with the beam, IMO), but they should have made sure that the deck would only rest on a lip of the shell if any contact is allowed.

or

 

[Bill1974]

That rebar has to potential to be an issue if it is not already. It's already been stated that the industry standard practice/method is to isolate the pool from the decking. And it for good reason, it's less likely to cause an issue with the pool structure.

Can they be tied together, yeah. But then you need to be more careful with the subsoil prep, rebar shape/placement and pour is one monolithic pour. And if everything isn't done right, most likely it will not crack where you are expecting it too and crack where you don't want it too.

 

[jcushman]

Thanks for all the advice and information everyone. I will talk to the pool builder and see where we go from here. The pool is 5 years old but I hope they will agree to take a look. I will update with any new information.

 

[ajw22]

Seeing the deck rebar run into the bond beam concerns me. I can't tell if the pieces connect or run up to the edge.

At a minimum I would want Stones 1, 2, and 3 popped off and replaced. Each of those stones should have expansion joints and isolation on all sides including between the adjoining stones. Rather then filling the gaps between the stones with mortar I would put foam backing rod and mastic between the gaps.

Long term I think the rebar connection between the deck and bond beam will lead to bond beam cracking and tiles cracking. I think what you are seeing is only the beginning. As others have said it can take deep saw plunge cuts to cut the rebar and create a true expansion joint that decouples the bond beam and deck.

 

[jcushman]

I'm pretty sure they don't connect, just run up to the edge. That is best seen in the pics in post#3 and #11. I'm wondering if what is causing the problem might be more evident if those stones were removed, particularly #1 which for sure has to be replaced anyway, to take a look at what is happening below.

Perhaps demo and replace the one section of decking where the problem is, cutting that rebar connection at the time. Also see if the channel drain to pipe connection is working correctly, and possibly alter how it functions.

 

[Jaffles]

Perhaps demo and replace the one section of decking where the problem is, cutting that rebar connection at the time. Also see if the channel drain to pipe connection is working correctly, and possibly alter how it functions.

think you have a good plan.

But while your there it may be worth also considering cutting that whole red expansion joint in post 6, the shell should just not be tied to the deck.