Concrete deck & expansion joint

[dw9000]

I am building a new inground pool, approx 18 x 36, vinyl liner. I am going to have the concrete guys poor a 12x36 deck on the north side of the pool for lounging, sun bathing, etc. Then around the rest of the pool a narrow 3 foot walk way.
The concrete is going to be poured right up to the aluminum cp2 coping.

Do I need anything more than the normal concrete expansion joints in the concrete (i.e. a normal sidewalk joints)? I was thinking I needed an expansion joint around the entire parameter of the pool, 18" in or so from the coping? I would prefer it not be there, but I through I read somewhere it was needed, but that might only be if a true coping (like limestone, quartz, etc) is being used.

 

[pooldv]

I think you are right, only need sidewalk style expansion joints perpendicular to the pool. If the concrete guy agrees then we are both right!

 

[Divin Dave]

No. you would not want an expansion joint between your cp2 coping and the concrete. Thats only necessary on pools with stone coping as you mention.

I would only add to make sure that control joints are properly placed in your 12x36 deck.
Control Joints are similar to expansion joints, but not quite the same...

So many times, folks dont know about control joints and in a few years, end up with some very unattractive and unruly cracks in their deck.

A GOOD concrete team will know that needs to be done, however in many instances, some concrete installers will either not do it, or not do it right. (these are usually the lowest bidders, and fly by nighters)
Never assume that your contractors will "do it right", expecially when it comes to concrete.

If you do a google search about concrete control joints, you will find a ton of info about them.

 

[Donny]

I agree with Dave. I have control joints in many places in my stamped concrete deck. Unfortunately I still had a few minor cracks. My deck is only a year old too. The most important thing is the sub base that they put down. Should be at least 4 inches of gravel and wire mesh.

 

[dw9000]

Thank you for your input. That confirms that I don't need the 'coping control / expansion joint'. I will make sure the concrete guy puts in plenty of control joints, likely cut in after the concrete dries, which they need to be careful cutting right up to the Cp2 coping.

I also want to make sure the area below the concrete is packed good. Right now I have the walls up (did concrete block), and there is about 2 feet between outside of block to the dirt, and over the winter the dirt caved in quite a bit. I went out and broke up the topsoil that slid in, tried to compact it. Obviously I need to get a good compaction to prevent the concrete above it from cracking. As soon as it is not too muddy, i plan on backfilling with sand, limstone screenings - it pacts pretty good, but I don't want to really pack it down with a machine until I get some inside pressure, I also need to still do the rough plumbing so I cannot total backfill until I get that in.
So I plan on backfilling w/o seriously tamping it. Once I get the liner in, fill the pool up then tamp it down, add 5 inches of stone, than concrete guys. Sound ok?