# Failed inspection



## big vic (Jan 23, 2012)

Got written up for mounting a breaker panel directly to a concrete wall. Inspector wants at least 1/4 in spacing between the cement wall and the panel. Can't find anything in the code book


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## Cow (Jan 16, 2008)

I couldn't give you a reference offhand. I'm just surprised your inspectors aren't required to cite code on your inspection reports like they are in Oregon...:blink:


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## madrone48 (Aug 15, 2012)

I'd ask for the reference on that one.


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## wildleg (Apr 12, 2009)

of course it's in the code. but most panels have dimples on the back to give you that 1/4".

300.6 D


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## toolaholic (Aug 13, 2010)

*I see his point*

The concrete wall could combust !!


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## drspec (Sep 29, 2012)

most 3R panels have that 1/4" nipple, but not sure many if any interior panels have it


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## big vic (Jan 23, 2012)

Doesn't 300.6d refer to wet locations? It's in a new residence basement


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## HARRY304E (Sep 15, 2010)

big vic said:


> Doesn't 300.6d refer to wet locations? It's in a new residence basement


An exterior wall of concrete is considered a damp location because of condensation.


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## big vic (Jan 23, 2012)

It's an interior concrete wall. So does all the raceways(EMT and 4x4 boxes) need to be spaced out 1/4 inch?


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## LARMGUY (Aug 22, 2010)

Clip the mounting hole off of a tie wrap and use as a standoff.


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## don_resqcapt19 (Jul 18, 2010)

HARRY304E said:


> An exterior wall of concrete is considered a damp location because of condensation.


The rule applies to wet locations, not damp locations.


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## ElectricJoeNJ (Feb 24, 2011)

How are you bringing all wires to the panel? Is it all EMT? Personally I think it's pretty hack not to put up a piece of ply.


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## HARRY304E (Sep 15, 2010)

don_resqcapt19 said:


> The rule applies to wet locations, not damp locations.


Your right Don I just read it again...:laughing:


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## electricmanscott (Feb 11, 2010)

HARRY304E said:


> An exterior wall of concrete is considered a damp location because of condensation.


It is?


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## BBQ (Nov 16, 2010)

electricmanscott said:


> It is?


Pretty much it is, that is why building codes require PT wood to be used when in contact with it.




(And by the way, 'It is?' sounds pretty darn contrarian.)


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## B4T (Feb 10, 2009)

BBQ said:


> Pretty much it is, that is why building codes require PT wood to be used when in contact with it.


I have never seen PT wood used to mount a panel and I have never seen a panel mounted directly to the concrete wall...

All that crazy talk must be those liberal Massholes... 

But I have seen a boat load of 3/4" painted plywood being used to mount panels... switches.. and anything else electrical.. :thumbsup:


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## therain (Jan 18, 2013)

312.2 applies to damp locations.


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## BBQ (Nov 16, 2010)

B4T said:


> I have never seen PT wood used to mount a panel and I have never seen a panel mounted directly to the concrete wall...
> 
> All that crazy talk must be those liberal Massholes...
> 
> But I have seen a boat load of 3/4" painted plywood being used to mount panels... switches.. and anything else electrical.. :thumbsup:


If. I need to rent a haul I will come to you for advice


But not so much about codes.:laughing:


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## sbrn33 (Mar 15, 2007)

B4T said:


> I have never seen PT wood used to mount a panel and I have never seen a panel mounted directly to the concrete wall...
> 
> All that crazy talk must be those liberal Massholes...
> 
> But I have seen a boat load of 3/4" painted plywood being used to mount panels... switches.. and anything else electrical.. :thumbsup:


I have never seen a piece of plywood used to mount a resi panel. Well since the sixties when they did not want to drill holes in the concrete.
Every thing is mounted to the concrete. Where do you mount the meter socket on a block building?


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## ElectricJoeNJ (Feb 24, 2011)

sbrn33 said:


> I have never seen a piece of plywood used to mount a resi panel. Well since the sixties when they did not want to drill holes in the concrete.
> Every thing is mounted to the concrete. Where do you mount the meter socket on a block building?


Meter sockets are 3r rated so they can be installed directly on block.


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## electricmanscott (Feb 11, 2010)

BBQ said:


> Pretty much it is, that is why building codes require PT wood to be used when in contact with it.
> 
> 
> 
> ...



I was actually asking, maybe I should have said "is it?" instead. :thumbup: :laughing:

I still don't buy it either way.


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## wildleg (Apr 12, 2009)

AFAIK, the X in CDX plywood means that the plywood uses an exterior rated glue and can be in permanent contact with moisture. I believe that is all that is needed for it to be used in this manner, of course, I'm no expert.

It is my opinion that the only reason they are selling treated plywood is because people are buying it. I think it was designed for boats.


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## BBQ (Nov 16, 2010)

wildleg said:


> AFAIK, the X in CDX plywood means that the plywood uses an exterior rated glue and can be in permanent contact with moisture. I believe that is all that is needed for it to be used in this manner, of course, I'm no expert.


I do not believe that to be true.




> CDX Plywood - What Does the "X" Really Mean?
> 
> The letter "X" in CDX refers to the type of glue used in the factory to bond the plywood veneers. Some mistakenly think the "X" stands for "exterior"—which is not true, exactly. The letter stands for exposure, which means the plywood is tough enough to withstand a little moisture—but for only a short time.



http://www.ezwoodshop.com/plywood/cdx-plywood.html

Here is some info from the 2006 building code, number 6 would apply to the wood behind an electrical panel in most basements.



> Chapter 3
> BUILDING PLANNING
> 
> SECTION R319
> ...


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## BBQ (Nov 16, 2010)

electricmanscott said:


> :
> 
> I still don't buy it either way.


If the inside of a concrete wall below grade is not 'damp or wet' can you explain why the building code requires treated lumber to be used?


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## B4T (Feb 10, 2009)

BBQ said:


> Here is some info from the 2006 building code, number 6 would apply to the wood behind an electrical panel in most basements.


Where does it say for mounting electrical equiptment.... :blink::blink:


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## BBQ (Nov 16, 2010)

B4T said:


> Where does it say for mounting electrical equiptment.... :blink::blink:


It does not, it does not have to.

It applies to wood mounted to the concrete regardless of what the wood was installed for.


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## Jlarson (Jun 28, 2009)

I just but some stainless nuts over my anchors as standoffs.


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## don_resqcapt19 (Jul 18, 2010)

BBQ said:


> It does not, it does not have to.
> 
> It applies to wood mounted to the concrete regardless of what the wood was installed for.


But there is there a need to install the wood, or can the panel be directly mounted to the wall?


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## BBQ (Nov 16, 2010)

don_resqcapt19 said:


> But there is there a need to install the wood, or can the panel be directly mounted to the wall?


No wood needed, I was just using that building code as an example.

I mount panels to concrete all the time and the have the required airspace.


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## BBQ (Nov 16, 2010)

Jlarson said:


> I just but some stainless nuts over my anchors as standoffs.


The VFDs in that water pit I did I used 3/8" nuts as spacers to hold them off the wall. Not stainless, we are not so fancy.


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## pjmurph2002 (Sep 18, 2009)

7/8" Unistrut works well and takes up very little space in the truck


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## denny3992 (Jul 12, 2010)

BBQ said:


> The VFDs in that water pit I did I used 3/8" nuts as spacers to hold them off the wall. Not stainless, we are not so fancy.


Be careful spacing vfds off walls, alot have cooling fins on the back and are made to be mounted on a solid flat surface for airflow design!


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## electricmanscott (Feb 11, 2010)

BBQ said:


> If the inside of a concrete wall below grade is not 'damp or wet' can you explain why the building code requires treated lumber to be used?


The lumber treaters got to the code makers?? :laughing:


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## brian john (Mar 11, 2007)

ElectricJoeNJ said:


> Meter sockets are 3r rated so they can be installed directly on block.


I do not think the NEMA 3R covers that, could be wrong and while it has been years since I saw a residential meter can, I think they have a 1/4" spacer as part of the design like many panrls.


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## Ashokan1 (Apr 11, 2013)

Could it be a utility requirement? I think that's the spec required by the utility for a main service panel in my area.


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## macmikeman (Jan 23, 2007)

We have an inspector in one of our area's that has decided that our level of humidity here makes all areas in a dwelling a damp location, tyvek be dammed. And he uses 90.4 to back himself up, and so no arguing with him about it..... Well, he hasn't done that to me yet, but we are on pretty good terms anyway. I usually find a whole lot of good sense in most of his whacky deviations from the code anyhow and just gladly follow along, cause I never seen him give me a (mandatory) suggestion that made something worse, only a better job anyway. Example- even if it is just a tiny apt kitchen- minimum three small appliance circuits in a kitchen to serve the counter, because everybody in Hawaii has a big rice cooker in the kitchen. Stuff like that.......


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## MF Dagger (Dec 24, 2007)

In commercial I put a couple pieces of standard strut to attach the panel to, then above the panel a few pieces of thick strut


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## bullmike (Jun 13, 2011)

The reason for mounting the panelboard on plywood is that concrete is a conductor. And also 408.20 a dry location.


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## Muslickz (Apr 19, 2013)

pjmurph2002 said:


> 7/8" Unistrut works well and takes up very little space in the truck


This is Exactly what we do, Always on block...

And it looks very professional when your done.

-Mus


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## Deep Cover (Dec 8, 2012)

bullmike said:


> The reason for mounting the panelboard on plywood is that concrete is a conductor.


Guess I should be putting plywood behind all my EMT sleeves and metal receptacle boxes then. :whistling2:


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## Southeast Power (Jan 18, 2009)

big vic said:


> Got written up for mounting a breaker panel directly to a concrete wall. Inspector wants at least 1/4 in spacing between the cement wall and the panel. Can't find anything in the code book


Loadcenters and some panelboards have the mounting holes raised 1/4". I just assumed that it was for this reason.


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## Shockdoc (Mar 4, 2010)

I just raul plugged a 100 amp panel directly to a poured slab wall last week. I bet it will outlast the old panel that was there.


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## BBQ (Nov 16, 2010)

don_resqcapt19 said:


> The rule applies to wet locations, not damp locations.





therain said:


> 312.2 applies to damp locations.


I agree




> *312.2 Damp and Wet Locations.* In damp or wet locations,
> surface-type enclosures within the scope of this article
> shall be placed or equipped so as to prevent moisture
> or water from entering and accumulating within the cabinet
> ...


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