At a pool trade show i went to earlier this year, a presenter said he was working on the next (or most recent?) NEC code which exempted concrete pools from having to use a seperate water bond, assuming the pool has an equipotential bonding grid in the concrete shell. It made sense to change this code because once the concrete is hydrated from the pool water it is in contact with the rebar inside of the concrete. However, i cant find this change online anywhere because its a fringe topic. does anybody know where i can look this up to show an inspector?
No longer needing to bond concrete pools
- Thread starter aatorch
- Start date
- Status
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Could this be it from the 2020 nec
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
This is the 2023
it doesnt say anything about the shell itself being used as a bonded part in direct connection with the pool water?
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
It does say that indirectly. It is saying that if there is bonding anywhere in (B)(1)-(7) that is in contact with the water then the pool water doesn't need bonding Sort of a backward way of saying it. At least that is how I read it
- Location
- Illinois
- Occupation
- retired electrician
The code has never required a separate water bond where the pool has a conductive shell. If any of the parts required to be bonded in accordance with 680.26(B) has at least 9 square inches in contact with the pool water, there is nothing more that is required. This has been the same, but with some language changes, ever since the pool water bonding requirement was added in the 2008 code.
(1) Conductive Pool Shells.
Bonding to conductive pool shells shall be provided as specified in 680.26(B)(1)(a) or (B)(1)(b). Cast-in-place concrete, pneumatically applied or sprayed concrete, and concrete block with painted or plastered coatings shall all be considered conductive materials due to water permeability and porosity.
just found it was close to that section thank you
Mystic Pools
Senior Member
- Location
- Park Ridge, NJ
- Occupation
- Swimming Pool Contractor
I too had heard that water bonding was not going to be required. I do however, ask the inspectors at our projects if they require it. It's not a big deal for us to install as we use the in-line type that is plumbed into the filtration system as opposed to the types that are installed on surface skimmers.
What I find interesting is the NEC's statement that: Cast-in-place concrete, pneumatically applied or sprayed concrete, and concrete block with painted or plastered coatings shall all be considered conductive materials due to water permeability and porosity.
I come at this from a different perspective as it relates to the American Shotcrete Assciation (ASA) notably the ASA Pool and Recreational Shotcrete Committee. Shotcrete refers to both wet and dry materials applied under pressure. My trade refers to gunite or shotcrete pools. Gunite being the dry method and shotcrete being wet. The American Concrete Institute(ACI) uses shotcrete as a term to designate either wet or dry method. It's material applied under pressure at high velocity.
The ASA's position papers regarding watertight structures not waterproof structures, states: Shotcrete placement that allows water to pass through the concrete of a pool shell is a sign of a flawed material or placement techniques.
So what I'm getting at is, if the NEC sees as pool shell as constantly wet, the rebar will fail prematurely. Then what happens to the water bonding aspect? What happens to the structure itself?
Requirements for finished compressive of concrete on pools is 4,000-5,000 PSI. There are additives available to make structures waterproof such as Xypex. They claim this. We use a topical watertight material called Basecrete with great success. I never claim a waterproofed shell.
If an electrician is not familiar with a pool contractor's concrete practices, it behooves one, IMO, to install a separate water bond in every case. It's not an expensive add on to the pool contractor but I feel it's added layer of protection for everyone involved.
- Location
- Illinois
- Occupation
- retired electrician
That is why some pool designers require fiberglass or epoxy coated rebar. In those cases, you will be required to install a copper bonding grid in the shell to provide the required bonding.
For the purposes of pool bonding, it would be my opinion, that any masonry type material is conductive and all you need to do is connect the bonding conductor to the rebar, assuming it has a conductive outer surface.
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