Cavie
Senior Member
- Location
- SW Florida
He is a link to a manufacturer of the copper wire mesh required NEC # 680.26
http://copperweld.com/cwwire/mesh.html
http://copperweld.com/cwwire/mesh.html
Pool bonding grid
- Thread starter Cavie
- Start date
- Status
Bob NH
Senior Member
- Location
- The "Live Free or Die" State
FROM THE PAGE AT THE LINK:Cavie said:
"Like the wire itself, the silver-brazed joints are highly resistant to corrosion. Moreover, electrical continuity is excellent since the resistance of any single joint is almost the same as the wire itself. The joints are capable of withstanding temperatures up to 4,500 degrees Centigrade, the recommended limit for brazed connections."
I always get a kick out of advetisements for whizz - bang products that demonstrate that those peddling the product don't have the foggiest idea what they are talking about. Steel and iron MELT somewhere in the range of 1400 to 1510 degrees Centigrade, so I doubt that anyone tested the joints at 4500 degrees Centigrade.
And I doubt that many contractors are going to use copper plated reinforcing steel for the grid when unplated steel reinforcing is permitted. I recall seeing recently a comment that welded steel mesh is permitted in lieu of reinforcing bars.
Cavie
Senior Member
- Location
- SW Florida
680.26 C (3) a and b discribe the bonding grid. It is to be #8 solid copper on 12" centers OR 1/2" structual rebar on 12" centers. Nowhere is steel wire mesh mentioned. Sorry I don't wright 'em I just reads 'em. In poured concrete, you would use the 1/2 metal rebar that is used in the wall of the pool. If using brick pavers, as the case in most of Sw Florida, you would use the copper wire mesh as it is not allowed to put rebar in contact with the earth. The copper wire mesh is laid in the sand and the pavers go on top.
dana1028
Senior Member
- Location
- San Francisco Bay area
Cavie said:
"OR 1/2" structural rebar?".... what code section was that again?...just curious, I just passed a grid with #3 rebar and would hate to have to go back and tell the fella he has to change out his grid rebar.
Cavie
Senior Member
- Location
- SW Florida
looking back today I don't know where I got the "1/2" measurement from but it is to the the Pool structual rebar.
rasmithircgov
Member
We are having a big discussion about this same thing in our dept. Maybe some can help.
1- wire mesh or no wire mesh?
2- exsisting porch slabs, do we require the bonding grid up to the exsisting slab only or when it is closer then 3' to pool shall the exsisting slab be cut so that the 3' can be installed?
1- wire mesh or no wire mesh?
2- exsisting porch slabs, do we require the bonding grid up to the exsisting slab only or when it is closer then 3' to pool shall the exsisting slab be cut so that the 3' can be installed?
bphgravity
Senior Member
- Location
- Florida
1. Here is a Non-Bonding Informal Interpretation as Provided by the BOAF. It's up to your BO to determine if the 6x6 WWF is acceptable or not:
2. Consult with your BO on this one as well. The code does not specifically provide guidance on existing perimeter surfaces within 36" of the pool leaving the interpretation up to the AHJ on how the section should be complied with.
2. Consult with your BO on this one as well. The code does not specifically provide guidance on existing perimeter surfaces within 36" of the pool leaving the interpretation up to the AHJ on how the section should be complied with.
g@friendly
Member
- Location
- NJ
I have been on this subject since feb of last year, being that I do just under 200 pools a year it is a big deal for me. Here in Jersey, they allow 3/8 rebar; as far as paver it is up in the air. I heard from an inpector at a NJEIA meeting that Suzan from the Jersey DCA is allowing steel mesh but nothing in writing yet. My biggest problem is when should the inspection for the grid be done. I disagree with AHJ to determinante when or how it should be done and inspect(to many townships). There are to many opinion. Personal I think the grid and inspection is after the mason are ready for concrete cause how are they going to tamp the dirt and set the forms as they walk all over the grid and break it apart. What are you guys getting for this job? 1350 3/8 rebar 2150 copper mesh.
rasmithircgov
Member
Hi Brian rasmith here,
Ive been on the other site also. I was just trying to get other minds out there to see what else has come up in discussion. As of right now I dont believe wire mesh should be allowed being that it isnt stated in the code even in alternate methods nor do I believe the wording supports such an interpetaion.
We wil do our inspection of the grid at slab and deck ( for slabs) and at bonding and grounding( for pavers)
Ive been on the other site also. I was just trying to get other minds out there to see what else has come up in discussion. As of right now I dont believe wire mesh should be allowed being that it isnt stated in the code even in alternate methods nor do I believe the wording supports such an interpetaion.
We wil do our inspection of the grid at slab and deck ( for slabs) and at bonding and grounding( for pavers)
bphgravity
Senior Member
- Location
- Florida
Rasmith,
Have you seen the wording that will likely be included in the 2008 NEC? It was not the intention of the CMP to exempt the use of WWM when it is used as the structural reinforcing steel in to perimeter surfaces. I have spoke with the Chair of CMP 17 directly on this very issue and used his guidance to assist the BOAF interpretation.
I am not saying the BOAF release has to be followed by the letter; however they are the only recognized organization to provide interpretations in the state of Florida as contracted with the DCA and the Florida Building Commission.
Have you seen the wording that will likely be included in the 2008 NEC? It was not the intention of the CMP to exempt the use of WWM when it is used as the structural reinforcing steel in to perimeter surfaces. I have spoke with the Chair of CMP 17 directly on this very issue and used his guidance to assist the BOAF interpretation.
I am not saying the BOAF release has to be followed by the letter; however they are the only recognized organization to provide interpretations in the state of Florida as contracted with the DCA and the Florida Building Commission.
rasmithircgov
Member
Yes I did. I guess I dont think that wire mesh should be in direct contact with the earth. I cant think of any wire mesh or its use that is allowed or supposed to be in contact with the earth. Therefore Im inclinded to say that if under pavers then the grid has to be of copper.
Heres the proposal for all who havent seen it yet.
Panel Meeting Action: Accept in Principle
Revise as follows:
680.26 Equipotential Bonding.
(A) Performance. The equipotential bonding required by this section shall be installed to reduce voltage gradients in
the pool area.
(B) Bonded Parts. The parts specified in 680.26(B)(1) through (B)(7) shall be bonded together using solid copper conductors, insulated covered , or bare, not smaller than 8 AWG or with rigid metal conduit of brass or other identified corrosion-resistant metal. Connections to bonded parts shall be made in accordance with 250. 8. An 8 AWG or larger solid copper bonding conductor provided to reduce voltage gradients in the pool area shall not be required to be extended or attached to any remote panelboard , to service equipment, or electrodes.
(1) Conductive Pool Shells. Bonding to conductive pool shells shall be provided as specified in 680. 26(B)(1)(a) or 680.26(B)(1)(b). Poured 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. Vinyl liners
and fiberglass composite shells ar shall be considered to be non-conductive materials.
a. Structural Reinforcing Steel. Unencapsulated structural reinforcing steel shall be bonded together by steel tie wires or the equivalent. Where structural reinforcing steel. encapsulated in a nonconductive compound, a copper conductor arid shall be installed in accordance with;- 680.26(B)(1)(b).
b. Copper Conductor Grid. A copper conductor grid shall be provided and shall comply with the following conditions:
(1) Be constructed of minimum 8 AWG bare solid copper conductors bonded to each other at all points of
crossing.
(2) Conform to the contour of the pool and the pool deck.
(3) Be arranged in a 300 mm (12 in. ) by 300 mm (12 in.) network of conductors in a uniformly spaced
perpendicular grid pattern with a tolerance of 100 mm (4 in.)
(4) Be secured within or under the pool no more than 150 mm (6 in.) from the outer contour of the pool shell.
(2) Perimeter Surfaces. The perimeter surface 2b extends for 1 m (3 ft) horizontally beyond the inside walls of the pool:- and shall includes unpaved surfaces as well as poured concrete and other types of paving. Bonding to perimeter surfaces shall provided as specified in 680. 26(B)(2)(a) or 680.26(B)(2)(b), and shall be attached to the pool reinforcing steel or copper conductor grid at a minimum of four (4) points uniformly spaced around the perimeter of the pool. For non-conductive pool shells , bonding at four points shall not be required.
(a) Structural Reinforcing Steel. Structural reinforcing steel shall be bonded In accordance with 680.26 (B)(1)(a).
(b) Alternate Means. Where structural reinforcing steel is not available or is encapsulated in a nonconductive compound, copper conductor shall be utilized where the following conditions are met:
(1) At least one minimum 8 AWG bare solid copper conductors shall be provided.
(2) The conductor(sl shall follow the contour of the perimeter surface.
(3) Onlv listed splices shall be permitted.
(4) The required conductor shall be 450 to 600 mm (18 to 24 in.) from the inside walls of
the pool.
(5) The required conductor shall be secured within or under the perimeter surface 100 to 150 mm (4 to 6 in.) below
the subgrade.
(3) Metallc Components. All metallc parts of the pool structure , including reinforcing metal not addressed in 680.26(1)(a), shall be bonded. Where reinforcing steel is encapsulated with a nonconductive compound the reinforcinq steel shall not be required to be bonded.
(4) Underwater Lighting. All metal forming shells and mounting brackets of no-niche luminaires shall be bonded.
Exception: Listed low-voltage lighting systems with nonmetallic forming shells shall not requirejr bonding.
(5) Metal Fittings. All metal fittings within or attached to the pool structure shall be bonded. Isolated parts that are not over 100 mm (4 in.) in any dimension and do not penetrate into the pool structure more than 25 mm (1 in. ) shall not require bonding.
(6) Electrical Equipment. Metal parts of electrical equipment associated with the pool water circulating system including pump motors and metal parts of equipment associated with pool covers , including electric motors, shall be bonded.
Exception: Metal parts of listed equipment incorporating an approved system of double insulation shall not be bonded.
(a) Double-Insulated Water Pump Motors. Where a double-insulated water-pump motor is installed under the provisions of this rule , a solid 8 AWG copper conductor tt of sufficient length to make a bonding connection to a replacement motor shall be extended from the bonding grid to an accessible point in the mo vicinity of the pool pump motor. Where there is no connection between the swimming pool bonding grid and the equipment grounding system for the premises , this bonding conductor shall be connected to the equipment grounding conductor of the motor circuit.
(b) Pool Water Heaters. For pool water heaters rated at more than 50 amperes and having specific instructions regarding bonding and grounding, only those parts designated to be bonded shall be bonded and only those parts designated to be grounded shall be grounded.
(7) Metal Wiring Methods and Equipment. Metal-sheathed cables and raceways , metal piping, and all fixed metal parts shall be bonded.
Exception No. 1: Those separated from the pool by a permanent barrier shall not be reauired to be bonded.
Exception NO. 2: Those greater than (5 ft) horizontally of the inside walls of the pool shall not be reauired to be bonded.
Exception No. 3: Those greater than (12 ft) measured vertically above the maximum water level of the pool, or as measured vertically above any observation stands, towers, or platforms, or any diving structures shall not be required to be bonded.
Panel Statement: The revised text more clearly presents the requirements and meets the intent of the submitter.
The panel has removed the word " (rebar)" from 680.26(B)(1)a to clarify that welded wire mesh can be included in the term "structural reinforcing steel" where acceptable to the authority having jurisdiction.
Heres the proposal for all who havent seen it yet.
Panel Meeting Action: Accept in Principle
Revise as follows:
680.26 Equipotential Bonding.
(A) Performance. The equipotential bonding required by this section shall be installed to reduce voltage gradients in
the pool area.
(B) Bonded Parts. The parts specified in 680.26(B)(1) through (B)(7) shall be bonded together using solid copper conductors, insulated covered , or bare, not smaller than 8 AWG or with rigid metal conduit of brass or other identified corrosion-resistant metal. Connections to bonded parts shall be made in accordance with 250. 8. An 8 AWG or larger solid copper bonding conductor provided to reduce voltage gradients in the pool area shall not be required to be extended or attached to any remote panelboard , to service equipment, or electrodes.
(1) Conductive Pool Shells. Bonding to conductive pool shells shall be provided as specified in 680. 26(B)(1)(a) or 680.26(B)(1)(b). Poured 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. Vinyl liners
and fiberglass composite shells ar shall be considered to be non-conductive materials.
a. Structural Reinforcing Steel. Unencapsulated structural reinforcing steel shall be bonded together by steel tie wires or the equivalent. Where structural reinforcing steel. encapsulated in a nonconductive compound, a copper conductor arid shall be installed in accordance with;- 680.26(B)(1)(b).
b. Copper Conductor Grid. A copper conductor grid shall be provided and shall comply with the following conditions:
(1) Be constructed of minimum 8 AWG bare solid copper conductors bonded to each other at all points of
crossing.
(2) Conform to the contour of the pool and the pool deck.
(3) Be arranged in a 300 mm (12 in. ) by 300 mm (12 in.) network of conductors in a uniformly spaced
perpendicular grid pattern with a tolerance of 100 mm (4 in.)
(4) Be secured within or under the pool no more than 150 mm (6 in.) from the outer contour of the pool shell.
(2) Perimeter Surfaces. The perimeter surface 2b extends for 1 m (3 ft) horizontally beyond the inside walls of the pool:- and shall includes unpaved surfaces as well as poured concrete and other types of paving. Bonding to perimeter surfaces shall provided as specified in 680. 26(B)(2)(a) or 680.26(B)(2)(b), and shall be attached to the pool reinforcing steel or copper conductor grid at a minimum of four (4) points uniformly spaced around the perimeter of the pool. For non-conductive pool shells , bonding at four points shall not be required.
(a) Structural Reinforcing Steel. Structural reinforcing steel shall be bonded In accordance with 680.26 (B)(1)(a).
(b) Alternate Means. Where structural reinforcing steel is not available or is encapsulated in a nonconductive compound, copper conductor shall be utilized where the following conditions are met:
(1) At least one minimum 8 AWG bare solid copper conductors shall be provided.
(2) The conductor(sl shall follow the contour of the perimeter surface.
(3) Onlv listed splices shall be permitted.
(4) The required conductor shall be 450 to 600 mm (18 to 24 in.) from the inside walls of
the pool.
(5) The required conductor shall be secured within or under the perimeter surface 100 to 150 mm (4 to 6 in.) below
the subgrade.
(3) Metallc Components. All metallc parts of the pool structure , including reinforcing metal not addressed in 680.26(1)(a), shall be bonded. Where reinforcing steel is encapsulated with a nonconductive compound the reinforcinq steel shall not be required to be bonded.
(4) Underwater Lighting. All metal forming shells and mounting brackets of no-niche luminaires shall be bonded.
Exception: Listed low-voltage lighting systems with nonmetallic forming shells shall not requirejr bonding.
(5) Metal Fittings. All metal fittings within or attached to the pool structure shall be bonded. Isolated parts that are not over 100 mm (4 in.) in any dimension and do not penetrate into the pool structure more than 25 mm (1 in. ) shall not require bonding.
(6) Electrical Equipment. Metal parts of electrical equipment associated with the pool water circulating system including pump motors and metal parts of equipment associated with pool covers , including electric motors, shall be bonded.
Exception: Metal parts of listed equipment incorporating an approved system of double insulation shall not be bonded.
(a) Double-Insulated Water Pump Motors. Where a double-insulated water-pump motor is installed under the provisions of this rule , a solid 8 AWG copper conductor tt of sufficient length to make a bonding connection to a replacement motor shall be extended from the bonding grid to an accessible point in the mo vicinity of the pool pump motor. Where there is no connection between the swimming pool bonding grid and the equipment grounding system for the premises , this bonding conductor shall be connected to the equipment grounding conductor of the motor circuit.
(b) Pool Water Heaters. For pool water heaters rated at more than 50 amperes and having specific instructions regarding bonding and grounding, only those parts designated to be bonded shall be bonded and only those parts designated to be grounded shall be grounded.
(7) Metal Wiring Methods and Equipment. Metal-sheathed cables and raceways , metal piping, and all fixed metal parts shall be bonded.
Exception No. 1: Those separated from the pool by a permanent barrier shall not be reauired to be bonded.
Exception NO. 2: Those greater than (5 ft) horizontally of the inside walls of the pool shall not be reauired to be bonded.
Exception No. 3: Those greater than (12 ft) measured vertically above the maximum water level of the pool, or as measured vertically above any observation stands, towers, or platforms, or any diving structures shall not be required to be bonded.
Panel Statement: The revised text more clearly presents the requirements and meets the intent of the submitter.
The panel has removed the word " (rebar)" from 680.26(B)(1)a to clarify that welded wire mesh can be included in the term "structural reinforcing steel" where acceptable to the authority having jurisdiction.
rasmithircgov
Member
At our weekly meeting the bonding grid was brought up. One of the questions was is welded wire mesh structual steel. I found a site American Concrete Intitute. I ask............
Inquiry: Is welded wire mesh by definition concidered structural steel?
They answered..........
Dear Robert:
ACI publishes codes, specifications, and reports for the concrete user. This message is in response to your technical question/inquiry.
Yes it is - as defined in ACI 318, Section 3.5
So now is this a repitable(sp) intity? and has or does anybody have access to this ACI 318, Sec 3.5?
My boss is very much considering wwm as strutual steel and to be used in concrete for the grid in slab. Copper can be used in slab also but in ground meaning for pavers only copper
Inquiry: Is welded wire mesh by definition concidered structural steel?
They answered..........
Dear Robert:
ACI publishes codes, specifications, and reports for the concrete user. This message is in response to your technical question/inquiry.
Yes it is - as defined in ACI 318, Section 3.5
So now is this a repitable(sp) intity? and has or does anybody have access to this ACI 318, Sec 3.5?
My boss is very much considering wwm as strutual steel and to be used in concrete for the grid in slab. Copper can be used in slab also but in ground meaning for pavers only copper
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