Gunite/Shotcrete Question

[ejhasan]

Hi all,

So I essentially have concrete cinder blocks for the walls of the pool. We are going to have it rebarred soon, but I was wondering if I need to put some sort of bonding agent for the shotcrete/gunite to adhere well to the concrete cinder blocks? I'm assuming I would be putting this on prior to placing the rebar because it will be hard to do with the rebar in place? Can the bonding agent be applied far in advance of shotcrete? Any agent you would recommend I use?

Thanks so much for your help! P.s. im new to this forum, so if I should be posting somewhere else, please let me know! I attached a picture.

 

[ejhasan]

Hi there,

So I had a non-electrician run some of the eletrcical conduit from the pool equipment to the pool breaker box (Pentair easytouch). He , however, did not secure the fittings well on the pool equipment and I was wondering if anyone had suggestions that would satisfy code (live in Nashville TN)? Links to parts would be very helpful, thank you thank you.

I want my new handyman to do some of this work before I get an electrian to hook the panel up. Thanks so much. Oh if you know a reasonable pool electrician who can pull a permit in Nashville let me know! Thanks

Also if this is suppose to be posted somewhere else please let me know, I am new to these forums!

 

[jdlangley1]

I could be totally wrong, but I didn’t think the particular cables you are showing had to be in conduit. I just took a look at my system and mine are not in conduit. The only things I see in conduit are the high voltage wires going to pump, heater, blower, etc. but the wires going to low voltage side (pump command wire, actuator valve wires, swcg cable, etc. are zip tied to pvc pipe and run to easy touch panel.

 

[1poolman1]

That was a lot of extra work but well worth it if you live in "critter" country. Good for him. Those cables are usually exposed with no issues. That pump communication cable is a $100.00 item by itself. The one on the SWG is usually not replaceable.
Having them in pipe/conduit will keep them from being gnawed on by animals. I would do that in the more rural areas around me when doing an install, or when repairing cables that had rodent damage.

 

[Toxophilite]

All those wood supports for the plumbing look permanently affixed and clamped to pipes, and there's a servicable valve in the mix. Are you planning to gunite a shell from both sides, tie all plumbing to rebar? Those supports will eventually rot and fail, leaving unsupported plumbing in the behind. Electrical conduit?

 

[AQUA~HOLICS]

Shotcrete/Gunite will adhere to the masonry blocks without a bonding agent.

 

[ejhasan]

Thanks so much for your replies, they are very helpful. So it sounds like it isn't code for the wiring from the salt generator, actuator valves, and low voltage from pool pumps to be in conduit? Since it is already mostly in conduit, is there a recommended way to have the conduit securely fit onto the actuator valves, salt generator, [low-voltage] pool pump? I thought about epoxy, but would rather have something that could removed in the future if necessary. Thanks so much for everyone's help.

 

[ejhasan]

All those wood supports for the plumbing look permanently affixed and clamped to pipes, and there's a servicable valve in the mix. Are you planning to gunite a shell from both sides, tie all plumbing to rebar? Those supports will eventually rot and fail, leaving unsupported plumbing in the behind. Electrical conduit?

Thank you so much for your reply, I really do appreciate your feedback. Good pick up on wood rotting and tying plumbing to the rebar. 90-95% of the plumbing will be surrounded by gunite, with only like 5-10% attached to wood. Even if the wood rotted won't the gunite keep the plumbing in place securely? Other people's thoughts as well? Again, thank you so much

 

[jwhitt]

I agree that the additional protection to your communication and SWG power cable isn't necessary. I'm more concerned with the mix of white and grey schedule 40 PVC, as an electrical inspector would fail any use of the white PVC being used for electrical conduit.

 

[ajw22]

Even if the wood rotted won't the gunite keep the plumbing in place securely?

No. The rotted wood will leave voids in the gunite that will compromise its structure.

Wood is the wrong material to use as spacers and support in a gunite pool.

Do you have a set of engineered plans for your pool showing the rebar and gunite structure or are you just designing on the fly?

 

[ajw22]

is there a recommended way to have the conduit securely fit onto the actuator valves, salt generator, [low-voltage] pool pump?

Those devices are not made to connect with conduit and you should not try to connect the conduit to them. Put some flexible silicone around the end of the conduit to keep water from getting in and you will be able to pull the wire out when it needs to be replaced, which it will be. A small portion of the wire will extend out of the pipe and connect to the device.

A strict electrical inspector will fail the mix of grey electrical PVC with white plumbing PVC. Maybe he will let is slide since it is low voltage and was not required. Good luck with that.

 

[ejhasan]

Hello,

I'd like to thank people ahead of time for their help. It is very much appreciated. When I bought my house many years ago it was originally suppose to have a pool put in, but eventually the builder had a change of plans and appears to have filled the concrete block space (where the pool was going to be) with dirt. Not too long ago, we excavated the dirt in the "concrete block pit" to put in a gunite pool.

I have been reading about expansion joints, but obviously the setup of my pool is a bit unique (please see pictures). The current plan is to put rebar in the "concrete block pit" and then gunite.

As you can see in the picture, half the pool already has a concrete walkway placed. After reading about expansion joints (I live in Nashville, TN), I think it will be necessary to put an expansion joint between the current concrete pathway(concrete pad) and the new gunite that will be placed.

My concern is, during the summer months, will the new rebar/gunite pool shell expand in the heat and push laterally on the concrete blocks below the concrete pad, below a portion of the house, and under some of the structural posts of the house, and cause structural concerns? Behind the blocks under the house (the picture where all the windows are) is an open crawl space. I am assuming the builder backfilled the other sides of the concrete block with either dirt or gravel.

Should I put some sort of compressable material on the concrete block prior to gunite that would absorb any expansion of the gunite? Is there a product you'd recommend? Will it bond well to both the block and gunite (placed at a later date)?

Any suggestions or thoughts on this would be helpful. Thanks in advance.

 

[1poolman1]

Thanks so much for your replies, they are very helpful. So it sounds like it isn't code for the wiring from the salt generator, actuator valves, and low voltage from pool pumps to be in conduit? Since it is already mostly in conduit, is there a recommended way to have the conduit securely fit onto the actuator valves, salt generator, [low-voltage] pool pump? I thought about epoxy, but would rather have something that could removed in the future if necessary. Thanks so much for everyone's help.

It isn't against any code to do that. Low voltage wiring doesn't require conduit but that conduit/pipe will protect the cable. There is no reason to attach the covering to the actuators, pump, or SWG, the cord already is well attached. No reason to remove unless you want to. Sealing the ends with silicone is a good idea so they don't fill with water.

 

[Toxophilite]

Thank you so much for your reply, I really do appreciate your feedback. Good pick up on wood rotting and tying plumbing to the rebar. 90-95% of the plumbing will be surrounded by gunite, with only like 5-10% attached to wood. Even if the wood rotted won't the gunite keep the plumbing in place securely? Other people's thoughts as well? Again, thank you so much

You are never going to get a chance to go back in there without major, major work and excavation. All contingencies need to planned for at this stage, before gunite. That was also why I asked about that check valve that appears will be cement over. Also, the electrical conduit inside pool shell.

 

[ajw22]

NEC requires a maximum of 360 degrees in bends in electrical conduit to facilitate pulling of wires through the conduit. That is a maximum of four 90's, And it is better to keep it to 3 90s to make it easier.

It looks to me in this pic you will not be able to pull the light wires through even if an inspector did not flag it.

 

[1poolman1]

Is there a permit on this project? Have never seen it legal to build a pool against what appears to be the foundation of the home.

 

[ajw22]

Should I put some sort of compressable material on the concrete block prior to gunite that would absorb any expansion of the gunite? Is there a product you'd recommend? Will it bond well to both the block and gunite (placed at a later date)?

Do you have a set of engineering plans for this build or are you designing on the fly?

I see code issues, structural issues, and general concerns that you will be putting your house foundation at risk with the pool up against it.

No concrete gunite pool stays absolutely water tight. Usually any leakage is into the surrounding soil and it just drains away. In your case you are putting the pool up against your house foundation without any barriers and in time you will get water under your house.

There are techniques to build pools on roofs of buildings and in structures. They use extensive water proofing barriers and often suspend the pool within a dry zone. So there are ways of safely doing what you want but not the way you are doing it.

.When I bought my house many years ago it was originally suppose to have a pool put in, but eventually the builder had a change of plans and appears to have filled the concrete block space (where the pool was going to be) with dirt. Not too long ago, we excavated the dirt in the "concrete block pit" to put in a gunite pool.

Your builder probably did not build the pool when he learned that the design would not work or be approved.

 

[ejhasan]

No. The rotted wood will leave voids in the gunite that will compromise its structure.

Wood is the wrong material to use as spacers and support in a gunite pool.

Do you have a set of engineered plans for your pool showing the rebar and gunite structure or are you just designing on the fly?

Doing it by the fly. Is there something you'd recommend to replace the wood with?

 

[ejhasan]

Do you have a set of engineering plans for this build or are you designing on the fly?

I see code issues, structural issues, and general concerns that you will be putting your house foundation at risk with the pool up against it.

No concrete gunite pool stays absolutely water tight. Usually any leakage is into the surrounding soil and it just drains away. In your case you are putting the pool up against your house foundation without any barriers and in time you will get water under your house.

There are techniques to build pools on roofs of buildings and in structures. They use extensive water proofing barriers and often suspend the pool within a dry zone. So there are ways of safely doing what you want but not the way you are doing it.


Your builder probably did not build the pool when he learned that the design would not work or be approved.

Hi. thank you for your reply. I am designing by the fly. The extensive waterproofing you mention: meaning waterproofing with a material with epoxy prior to plastering and applying the pool finish? Will that be sufficient? Can you expand upon suspending the pool within a dry zone? Any videos or resources you know about this? Do you have similar concerns with the gunite pool shell expanding into the concrete blocks? Any suggestions?

If I knew all these "complications" ahead of time, I would have never dug out the courtyard area. I've obviously put a lot of money and time into this project so far, trying to salvage the project, but thanks for raising your concerns.

 

[ajw22]

You do the rebar first to frame the shell.

Then you run the plumbing inside the rebar. You use wire ties to position the PVC inside the rebar.

With a concrete block pool you trench the outside of the blocks and most of the piping runs outside the blocks to where you penetrate a hole.

I realize two of the walls are along your foundation. What is on the other side of the blocks? Do you have a crawl space under the house foundation?

The only thing I would replace the wood with is PVC cut to form spacers and support.

You really need to get a pool engineer to look at your plans.

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