Looking for concrete advice, replacing part of my deck slab

[Camaro4life18]

My inground pool is 30 years old, which had a 30 year old diving board. The base of the board was extremely rusted when I moved into the house 2 winters ago, and I took the board out because I didn't trust it. This spring I am working on putting in a new diving board. I didn't like the idea of drilling holes and anchoring with concrete epoxy, so I decided to tear up a ~5'x5' slab and repour new concrete. My question is, should I use a foam expansion joint between the old slab and the new I'm pouring, or should I anchor it with rebar to the old?

Here's a pic of what I have torn out.

 

[Bperry]

My inground pool is 30 years old, which had a 30 year old diving board. The base of the board was extremely rusted when I moved into the house 2 winters ago, and I took the board out because I didn't trust it. This spring I am working on putting in a new diving board. I didn't like the idea of drilling holes and anchoring with concrete epoxy, so I decided to tear up a ~5'x5' slab and repour new concrete. My question is, should I use a foam expansion joint between the old slab and the new I'm pouring, or should I anchor it with rebar to the old?

Here's a pic of what I have torn out.

Your picture isn’t showing up. The diving boards I’ve seen have some recommendations for footings to anchor the board supports. I’d think if you did those, you wouldn’t need to tie the old and new slabs together.

 

[Camaro4life18]

Your picture isn’t showing up. The diving boards I’ve seen have some recommendations for footings to anchor the board supports. I’d think if you did those, you wouldn’t need to tie the old and new slabs together.

There, I fixed it. The board installation instructions just say I need a 4'x8' slab 6" thick of 3500+ PSI. I talked to my father, who has construction experience, but not a concrete expert, and he said for this job it really doesn't matter. I've already set up to anchor it all together. So I'll probably just do that, and then use a joint sealer to prevent any water from getting in.

 

[Bperry]

There, I fixed it. The board installation instructions just say I need a 4'x8' slab 6" thick of 3500+ PSI. I talked to my father, who has construction experience, but not a concrete expert, and he said for this job it really doesn't matter. I've already set up to anchor it all together. So I'll probably just do that, and then use a joint sealer to prevent any water from getting in.

Well it does somewhat matter because an adult jumping on that board can put some serious leverage on whatever it’s anchored to. If the manufacturer says you need a 4x8x6” slab you would be wise to do that. Your current slab looks shorter than 8’ so tying them together is the better thing to do.

 

[Camaro4life18]

Well it does somewhat matter because an adult jumping on that board can put some serious leverage on whatever it’s anchored to. If the manufacturer says you need a 4x8x6” slab you would be wise to do that. Your current slab looks shorter than 8’ so tying them together is the better thing to do.

Yeah, I left that part out, I dug out another 2 feet and set up forms to make it 8' long.

 

[Mdragger88]

Is the pool deck bonded? It often meets the bonding requirements via the rebar being tied together if it is on an older pool so you want to make sure you keep that.
Lets ask a few guys that can give better advice on the subject to be sure you’re covering all the bases. @ajw22 , @JamesW

 

[ajw22]

That replacement slab needs to meet the perimeter bonding requirements of the NEC 680 and any metal in the diving board and supports needs to be connected to the pool bonding grid.

 

[Camaro4life18]

Yes, the pool is bonded. Its hard to make out in the picture, but there is a copper wire sticking up/wrapped around that piece of angle iron supporting the pool. It was "attached" to the old diving board jig. I was planning to reuse it and attach it to the new rebar and diving board jig. The only thing is they just wrapped it around the old jig. Grounding is my father's specialty, as he was an electrician for 35 years. I know when they install a grounding field all the copper gets welded together to ensure a good bond. Wrapping copper around rebar doesn't seem like a good bond. Is that common practice for pool installations?

 

[ajw22]

Grounding is my father's specialty, as he was an electrician for 35 years. I know when they install a grounding field all the copper gets welded together to ensure a good bond. Wrapping copper around rebar doesn't seem like a good bond. Is that common practice for pool installations?

Bonding with a pool is different then grounding. Your father should review NEC 680.26 which is specific to pool bonding.

Bonding vs Grounding

Electricity and water don't mix. Learn a few basic tips how to keep your family safe when dealing with electricity around your pool.

www.troublefreepool.com

Electrical Bonding - Further Reading

www.troublefreepool.com

 

[Bill1974]

I am guessing the 4 ft width at the pool wall and the 8 ft is offset from the pool wall. 6" thick seems appropriate for a diving board. I have the U shapes ones and they are imbedded in concrete a foot and half or more deep with rebar. Follow the instructions for the mount you are using and also make sure it's compatible with the board too. Not all board can be mounted on all mounts.

 

[Camaro4life18]

Bonding with a pool is different then grounding. Your father should review NEC 680.26 which is specific to pool bonding.

Thanks for the bonding info! Good to make sure I do it right.

I am guessing the 4 ft width at the pool wall and the 8 ft is offset from the pool wall. 6" thick seems appropriate for a diving board. I have the U shapes ones and they are imbedded in concrete a foot and half or more deep with rebar. Follow the instructions for the mount you are using and also make sure it's compatible with the board too. Not all board can be mounted on all mounts.

Possibly, my width is 5.5', and I'm just going to go ahead an add the extra couple of feet to make it 8' long. No sense in skimping out on another $100 of concrete. I bought the board and mount together.
I got the SR Smith Salt Pool Jump System. I don't have a salt pool, but hopefully the extra coatings will make it last longer. Plus it came all together as a kit.

 

[Bill1974]

The salt water versions I believe are 316 stainless steel vs 304 stainless steel for the hardware and maybe some of the metal parts (that was the differece for my pool ladder). For the threaded rod/bolts that anchors into the concrete go for stainless steel ones (any 300 series stainless steel, 400 series will rust, the less magnetic the better) so you don't get rusting down the road. Also put a little oil/grease on the threads of the fasteners so they don't gall up when you tighten them down and use hand tools. The faster turning from power tools will likely cause them to gall up and then you can't properly tighten them.