Exterior Hot Tub Bonding...

1793

Senior Member
I'm looking a project that involves wiring an exterior Hot Tub.

My question is concerning the bonding of "all metal surfaces that are within 5ft of the inside walls of the spa or hot tub that are not separated by a permanent barrier" as required by 680.43(D)(4)

680.43 deals with Indoor Installations, do the same requirements exist for exterior installations.?

Thanks
 

Dennis Alwon

Moderator
Staff member
Did you read this... If your tub is a manufactured tub and meets these requirements than no equipotential bonding is needed. The tub itself should have all the necessary bonding. Now if this is a hot tub than is built in as part of a pool then you have a different issue

(B) Bonding. Bonding by metal-to-metal mounting on a
common frame or base shall be permitted. The metal bands
or hoops used to secure wooden staves shall not be required
to be bonded as required in 680.26.
Equipotential bonding of perimeter surfaces in accordance
with 680.26(B)(2) shall not be required to be provided
for spas and hot tubs where all of the following
conditions apply:
(1) The spa or hot tub shall be listed as a self-contained spa
for aboveground use.
(2) The spa or hot tub shall not be identified as suitable
only for indoor use.
(3) The installation shall be in accordance with the manufacturer’s
instructions and shall be located on or above
grade.
(4) The top rim of the spa or hot tub shall be at least
710 mm (28 in.) above all perimeter surfaces that are
within 760 mm (30 in.), measured horizontally from
the spa or hot tub. The height of nonconductive external
steps for entry to or exit from the self-contained spa
shall not be used to reduce or increase this rim height
measurement.
 

1793

Senior Member
Did you read this... If your tub is a manufactured tub and meets these requirements than no equipotential bonding is needed. The tub itself should have all the necessary bonding. Now if this is a hot tub than is built in as part of a pool then you have a different issue
I say I have/did. I think I understand the "EquipBond" requirement but I was wondering if metal within 5' of the tub needs to be bonded like required for an interior installation, 680.43(D)(4)

Maybe I'm not understanding what I'm reading as mentioned in your replay.
 

Dennis Alwon

Moderator
Staff member
Yes, bonding of all metal parts 5' from the tub must be bonded both interior and exterior. Exterior tubs basically follows parts I & II which means it is bonded as a pool would be except fr the perimeter bonding that I quoted above.
 

cpinetree

Senior Member
Has nothing to do with bonding, but watch out if you have any windows close to the install. We recently needed to change the regular glass in one, to tempered glass. Along with bonding the metal frame.
 

Dennis Alwon

Moderator
Staff member
Has nothing to do with bonding, but watch out if you have any windows close to the install. We recently needed to change the regular glass in one, to tempered glass. Along with bonding the metal frame.
What has nothing to do with bonding?
 

1793

Senior Member
Yes, bonding of all metal parts 5' from the tub must be bonded both interior and exterior. Exterior tubs basically follows parts I & II which means it is bonded as a pool would be except fr the perimeter bonding that I quoted above.
Bonding, in my opinion, should be the same for exterior as interior. I just found it strange that if it is the same for both why have it specifically called out in interior and not exterior which is listed first.
 

Dennis Alwon

Moderator
Staff member
Bonding, in my opinion, should be the same for exterior as interior. I just found it strange that if it is the same for both why have it specifically called out in interior and not exterior which is listed first.

It is called out, sort of, by referencing Parts I and II for outdoor tubs
 

raykit65

Member
Did you read this... If your tub is a manufactured tub and meets these requirements than no equipotential bonding is needed. The tub itself should have all the necessary bonding. Now if this is a hot tub than is built in as part of a pool then you have a different issue

I am installing a 2 person manufactured hot tub (molded polyethylene); I wasnt planning on implementing an equipotential bonding grid. The concrete is set to pour this week...

In reviewing the requirements you listed however I think I might now need to do it as the tub is only 27" tall. There is nothing within 10' that would require bonding or any other reason that I can see. Does this alone require it?

I have previously installed larger manufactured hot tubs without a grid (never had an issue). But those were taller than 28"

Thoughts?
 

Dennis Alwon

Moderator
Staff member
I am installing a 2 person manufactured hot tub (molded polyethylene); I wasnt planning on implementing an equipotential bonding grid. The concrete is set to pour this week...

In reviewing the requirements you listed however I think I might now need to do it as the tub is only 27" tall. There is nothing within 10' that would require bonding or any other reason that I can see. Does this alone require it?

I have previously installed larger manufactured hot tubs without a grid (never had an issue). But those were taller than 28"

Thoughts?

Sounds like you need equipotential bonding. Run a bare #8 around the perimeter of the tub between 18-24" from the tub and 4-6" deep.
 

raykit65

Member
Sounds like you need equipotential bonding. Run a bare #8 around the perimeter of the tub between 18-24" from the tub and 4-6" deep.
Not really what I wanted to hear but I definitely am seeing it your way too...

The new pad of concrete is the same size of the hot tub's footprint. Not sure how to lay out my wire 18"-24" outside of that. Do I need to recommend the pad be larger? If not what are my options? Also, the front of the tub will be immediately adjacent to the existing patio. Do I need to tear into that?image.jpg
 

kwired

Electron manager
Not really what I wanted to hear but I definitely am seeing it your way too...

The new pad of concrete is the same size of the hot tub's footprint. Not sure how to lay out my wire 18"-24" outside of that. Do I need to recommend the pad be larger? If not what are my options? Also, the front of the tub will be immediately adjacent to the existing patio. Do I need to tear into that?View attachment 15659
What is the existing patio? Concrete, wood, etc.?

Maybe I should have looked at your picture:slaphead:
 

Dennis Alwon

Moderator
Staff member
I realize I answered this via pm the other day but for the benefit of all it is my opinion that the existing concrete will have to be either cut open or if you could undermine it and meet the requirements of 18-24 inches from the tub and 4-6 inches below subgrade.
 

jim dungar

Moderator
Staff member
The new pad of concrete is the same size of the hot tub's footprint.
If the new concrete pad was the same size as the tub couldn't it be made 2" above grade, thereby elevating the rim of the tub a minimum of 28" above any perimeter surface?
 

JFletcher

Senior Member
If the new concrete pad was the same size as the tub couldn't it be made 2" above grade, thereby elevating the rim of the tub a minimum of 28" above any perimeter surface?
:thumbsup:

Getting a few $5 bags of concrete and pouring the get that inch would be much cheaper and faster than cutting and a grid. or a few (lot, a whole lot) more bags to raise it up 4" if you need the grid.

an 80lb bag only does 2/3 ft[SUP]3[/SUP].
 

raykit65

Member
If the new concrete pad was the same size as the tub couldn't it be made 2" above grade, thereby elevating the rim of the tub a minimum of 28" above any perimeter surface?
I actually thought of this as well...

I presented 3 options to the homeowner:
1. Tear up the existing patio
2. Raise the new slab 2"to meet minimum requirement
3. Extend the new slab at least 18" beyond what was originally planned

We both decided on extending the slab. While raising it was an option, the added protection of adding the bonding was important to me.
 
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