Pool bond with mesh and concrete question

[Dennis Alwon]

So to this no go?

Augie. Why in your area would it be good in

Denise you mentioned no go then go.

Denise is a female ----- dennis-- get it right LOL

I said the copper layout above was a no go because it was larger than 12x12. You keep throwing in different pics so I don't know what you have there.

 

[augie47]

Denise, I'm not challenging you, but clarifying. In your opinion, if a pool deck was poured and the G/C installed standard concrete mesh on top of the gravel and the mesh was bonded together and boned to the pool framework on four corners, would that make an acceptable perimeter bond ?
On the other hand, the copper grid shown in the post #16 picture would not ?

(I can see the 12x12 requirement for the pool shell, but not for the perimeter surface)

 

[Dennis Alwon]

Denise, I'm not challenging you, but clarifying. In your opinion, if a pool deck was poured and the G/C installed standard concrete mesh on top of the gravel and the mesh was bonded together and boned to the pool framework on four corners, would that make an acceptable perimeter bond ?
On the other hand, the copper grid shown in the post #16 picture would not ?

(I can see the 12x12 requirement for the pool shell, but not for the perimeter surface)

Challenge me--- that's good--- keeps us thinking-- in 680.26(B)(2) Perimeter surfaces it states we must use a or b so if there is structural reinforcing steel then I would think it would suffice for the perimeter bond. That is my take on it

 

[augie47]

Challenge me--- that's good--- keeps us thinking-- in 680.26(B)(2) Perimeter surfaces it states we must use a or b so if there is structural reinforcing steel then I would think it would suffice for the perimeter bond. That is my take on it

I guess you are right since the wire shown in Post 16 is not reinforcing steel and is not 4-6" below sub grade.
Seems odd though that we can accept a steel concrete mesh wire and not accept the copper mesh shown in that post.

 

[Dennis Alwon]

I guess you are right since the wire shown in Post 16 is not reinforcing steel and is not 4-6" below sub grade.
Seems odd though that we can accept a steel concrete mesh wire and not accept the copper mesh shown in that post.

I think that whole section needs work. I might attack it but I don't know if I have the energy for that one.

 

[ritelec]

Sorry Dennis, a thousand pardons.

sent the last pics from my phone.

here they are.
from what is being said here I think this install is wrong.

stone then mesh which is bonded then pour. The solid 8 is laying on the stone under the mesh.

and as far as the laying number 8 on the dirt or dust then pavers on top. I past one with the 8x8 squares 6 or 7 yrs ago then one with the single 8 last years.
I vaguely remember the update course 4 years ago mentioning they want to see it closer to the top, right under the pavers.

I don't doubt what you guys are saying. would be nice to be on the same page...
for my own head, here's the pics. of a pour install. thumbs up or down? (this is not the poolman job, these pics are from off the internet)

 

[augie47]

thumbs up for me

 

[ritelec]

thumbs up for me

OK. Why,

It's not structural to the pool and the single 8 isn't 4-6" down from the subgrade. It's on top of the stone. Under the mesh.

wondering

 

[augie47]

The 2008 Code changed the wording (removing re-bar) so that welded mesh is considered to be structural reinforcing steel.
Without the mesh the "alternate method" would be needed and your #8 would have to be below subgrade,

 

[ritelec]

Thank you, that's good to know.

does it say someplace that welded mesh is considered structural steel?

either in the 08 or 11?

 

[ritelec]

Thank you..

Gonna stop beating the dead horse now.

 

[augie47]

Thank you, that's good to know.

does it say someplace that welded mesh is considered structural steel?

either in the 08 or 11?

Obviously, can't say that the Code says that directly. The explaination came from the IAEI Analysis of Change . I assume there is information relative to that in the 2008 ROPs or ROCs but I have not researched it.
Dennis may know. He's sharp on pools.

 

[markerblack]

Welded Mesh

Welded Mesh

Thank you, that's good to know.

does it say someplace that welded mesh is considered structural steel?

either in the 08 or 11?

Fairly certain that welded mesh cannot be considered structural - if we are talking about the same material.

I have never seen or read any code that can show this as "structure".

Please do me a favor here and correct me if I am in fact wrong on this - would be very nice to know.

Thanks,

 

[north star]

+ & + & +

ritelec asked:
thank you, that's good to know
does it say someplace that welded mesh is considered structural steel?
either in the 08 or 11?"

To be considered structural steel, ..the application in to which
steel reinforcement is to be installed would need to be evaluated by a structural
engineer.

True structural steel reinforcement is manufactured in many dimensions.
There is steel reinforcement bars, ...reinforcement welded wire mesh,
...reinforcement welded wire fabric and other of types steel reinforcement.
[ RE: welded wire steel sheets, also known as "highway matt" ].......When
considering installing steel reinforcement in to a pool patio deck area;
whether that is "re-bars', ...or welded wire fabric [ wwf ], or welded wire mesh
[ wwm ], or something else, for the most part it is irrelevant, because concrete
has a very high comprehensive strength, but not a good lateral strength.
In your [ typical ] pool patio areas, the only vertical loads that will ever be
imposed on the pool decking is the foot traffic of the people walking around on
it, thus no steel reinforcement [ by definition ] is required in the pool decking
areas.

Most contractors install steel reinforcement in these areas, because the steel
provides a skeletal framework on to which the concrete can attach and bond to,
thereby, [ at least in theory ] , ...providing a stronger application of the concrete
placement.

Definitions of and instructions on how to install the various types of steel
reinforcement can be found in the ACI-318 Standard [ American Concrete
Institute - 318 Standard ].

FWIW, ...if a type of steel reinforcement is installed in to any type of concrete
placement project, ...it should be so constructed so that when the concrete is
placed, ...the steel reinforcement should remain in the very center of the
concrete placement areas.......Centered vertically that is !



+ & + & +

 

[hurk27]

IMO that is a no go.... The idea is to make contact with the earth in case there is stray voltage. In reality it may not make a difference but that IMO is not compliant.

The idea is to create an area of equal potential, Earth does not have anything to do with this as we all have said that the resistance of earth is to high to remove the stray voltage, the reason the NEC wants a single copper conductor deeper is because you need the earth around the copper to act as the EPG, which will spread out the effective area of the single coper wire, a grid in concrete does not need this or does a grid in earth, so they can be right on top as is done in concrete where the concrete itself acts as the EPG.

Don't mix the requirements for a EPG with the requirements for a CEE, where the copper wire or re-bar is required to be down close to the bottom of the concrete, the requirements for a CEE electrode are a whole different requirement and for different reasons.

If you notice that 680.26(B)(2) does not have a depth requirement for the grid just for where a single copper wire is used in 680.26(B)(2)(b) Alternate Means. 4"-6" below grade if not installed in concrete which it has no instruction on where in the concrete it must be installed unlike that for a CEE, it only says within the concrete.

Below is from the 2011 handbook:

The perimeter bonding grid can be comprised of structural
reinforcing metal (rebar or welded wire mesh) that is
conductive to the perimeter surface and installed in or under
the perimeter surface. Where structural reinforcing steel is
not available, a single, bare, solid 8 AWG or larger copper
conductor can be installed around the perimeter of the pool
in an area measuring between 18 in. and 24 in. from the inside
pool walls. This 8 AWG bonding conductor can be installed
in the paving material (i.e., in the concrete), or it can
be buried in the material (subgrade) below the paving material.
Where buried, the bonding conductor is to be not less
than 4 in. and not more than 6 in. below the surface level of
the subgrade material.

Also to add: Don't miss the word "or" as it has great importance to the understanding of the requirement.

 

[mgookin]

+ & + & +

To be considered structural steel, ..the application in to which
steel reinforcement is to be installed would need to be evaluated by a structural
engineer.

True structural steel reinforcement is manufactured in many dimensions.
There is steel reinforcement bars, ...reinforcement welded wire mesh,
...reinforcement welded wire fabric and other of types steel reinforcement.
[ RE: welded wire steel sheets, also known as "highway matt" ].......When
considering installing steel reinforcement in to a pool patio deck area;
whether that is "re-bars', ...or welded wire fabric [ wwf ], or welded wire mesh
[ wwm ], or something else, for the most part it is irrelevant, because concrete
has a very high comprehensive strength, but not a good lateral strength.
In your [ typical ] pool patio areas, the only vertical loads that will ever be
imposed on the pool decking is the foot traffic of the people walking around on
it, thus no steel reinforcement [ by definition ] is required in the pool decking
areas.

Most contractors install steel reinforcement in these areas, because the steel
provides a skeletal framework on to which the concrete can attach and bond to,
thereby, [ at least in theory ] , ...providing a stronger application of the concrete
placement.

Definitions of and instructions on how to install the various types of steel
reinforcement can be found in the ACI-318 Standard [ American Concrete
Institute - 318 Standard ].

FWIW, ...if a type of steel reinforcement is installed in to any type of concrete
placement project, ...it should be so constructed so that when the concrete is
placed, ...the steel reinforcement should remain in the very center of the
concrete placement areas.......Centered vertically that is !



+ & + & +

I think you meant to compare and contrast compressive strength with tensile strength. The physical properties of concrete provide for favorable compressive strength but lack in tensile strength; that's why we use steel reinforcement because steel has favorable properties in tensile strength.

As to vertical placement of horizontal reinforcement, your statement of "half way up" is not quite correct. A horizontal beam is under tension at the bottom of the beam and compression at the top of a beam. Maybe you got confused regarding concrete cover which requires the reinforcement to be a minimum distance from any edge of the concrete for both structural reasons and to prevent the reinforcement from decay by exposure to the elements.

Welded wire in a slab counteracts gravity when the soils shift or settle preventing not only slab damage but also tripping hazards. In a 3-1/2" thick slab on grade it may be preferable to have that welded wire half way between the top and bottom in order to maintain concrete cover. In a perfect world where nothing ever moved it would not be necessary to have welded wire in the slab but we know the world is not perfect and soils are in constant motion on Earth.

I've never heard of bonding welded wire to an EPG but it's logical. I had never heard of illuminating an exit discharge either and I think it was you who educated me on that one. It certainly is something to consider.

 

[Diesel323]

So after all this debate would i be correct in thinking i can run my bond ring on the ground directly below the concrete and just bond it to to the mesh.