# plywood behind panel



## sbrn33

Na, I think it's an east coast thing.


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## LARMGUY

I do it all the time in access control, phones, alarm systems. We had one customer that specified fire resistant plywood then they painted it with oil based enamel.


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## B4T

sbrn33 said:


> Na, I think it's an east coast thing.


Very true.. I have never seen a panel mounted directly to a concrete or block wall..

It does make for a better job using a 3/4" 2'X4' piece of plywood to mount the panel on..

HD sells them pre-cut.. you can't do any better than that.. :thumbsup:

I have seen a few hacks who are too cheap to buy 3/4".. so they buy (2) pieces of 1/2" plywood instead.. :no::no:


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## 347sparky

It's common practice here to use plywood or strut on an outer block or concrete wall for the panel to mount on.


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## sbrn33

1000's of panels mounted to the concrete or block walls with 4-#10 screws and plastic anchors. Every one inspected.
No SE cable here though.


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## B4T

sbrn33 said:


> 1000's of panels mounted to the concrete or block walls with 4-#10 screws and plastic anchors. Every one inspected.
> No SE cable here though.


How are the cables secured above the panel??


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## Speedy Petey

Plywood just makes everything easier and cleaner IMO. 

I use 3/4" AC or BC. I like to paint mine with grey floor paint.


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## sbrn33

B4T said:


> How are the cables secured above the panel??


Normally stapled to the sill plate. A lot of guys will run one 2" PVC and run them through that.

I am not against the plywood but it does seem like one extra step unless you do have it precut.


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## frenchelectrican

The plywood look alot neater plus you can able secure the conduit or cable without issue and the typical materal I use is either 3/4 inch CDX or 20mm marine grade plywood one of the two depending on where I snag it.

Few of them I will tapconned to concrete and some will be floated with strut channel.

And Oui ., I do paint them as well either Noir ( Black ) or Gris ( Grey ) 

Merci,
Marc


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## sbrn33

How could one mounted on plywood look nicer than one mounted right to the wall? To each their own.


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## Speedy Petey

sbrn33 said:


> How could one mounted on plywood look nicer than one mounted right to the wall? To each their own.


For me it would be securing of cables and ease of mounting things like boxes off the panel.


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## etb

Very rarely see plywood backed panels here unless it's outside on a pole. Tapcon or redhead either direction into the concrete or a 2x4 scab.


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## backstay

sbrn33 said:


> Normally stapled to the sill plate. A lot of guys will run one 2" PVC and run them through that.
> 
> I am not against the plywood but it does seem like one extra step unless you do have it precut.


I hope they derate those cables.


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## B4T

*This is for guys looking for a better way.. IMO*

Here is a simple way of mounting plywood to a concrete or block wall.. I use it every time and works like a charm..

Drill (5) 1/4" holes in the plywood.. one dead center and the other (4) at all the corners..

I like to go 1.5" from each side on the corners.. it just makes a uniform design..

Layout where the center hole would be and drill 1/4" hole 1.5" deep..

Use your Phillips screwdriver through hole in wood and into hole in concrete.. my Craftsman Phillips is a perfect 1/4"..

Now the plywood is held to the wall and you can work freely with both hands..

Level the wood and drill a hole into the concrete.. insert a pin anchor and bang it home..

This information is useless to most of you.. .. but I have used the same technique to hang a 4'X8' sheet by myself..

All you need are (2) legs to rest the plywood on and go for the center hole..

Some here will say all of the above is a waste of time.. just use a Ramset and shoot it to the wall..

As you know.. sometimes those nails don't hold.. but the pin anchors never fail to set right..


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## B4T

sbrn33 said:


> How could one mounted on plywood look nicer than one mounted right to the wall? To each their own.


Sometimes the panel mounted on plywood is the best looking thing in the whole basement..


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## user4818

B4T said:


> This information is useless to most of you.. ..


Not useless, just odd. I've never seen plywood hammer pinned to the wall. The common practice is to mount 2X4's or deck boards to the wall first, them mount the plywood on that. 

I've mounted exactly one panel directly to the concrete.


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## sbrn33

Yea, I have used plywood when the basement wall is really ****ty or corroding away. I am not against the plywood, just don't need it here.


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## B4T

Peter D said:


> Not useless, just odd. I've never seen plywood hammer pinned to the wall. The common practice is to mount 2X4's or deck boards to the wall first, them mount the plywood on that.
> 
> I've mounted exactly one panel directly to the concrete.


I have never seen 2X4's mounted first and then plywood on top of that.. just a useless step.. IMO..


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## user4818

B4T said:


> just a useless step.. IMO..




And using hammer pins is better?


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## Cletis

*Wicking*



B4T said:


> I have never seen 2X4's mounted first and then plywood on top of that.. just a useless step.. IMO..


It's cuz of the wicking/sponge effect


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## B4T

Peter D said:


> And using hammer pins is better?


Yes.. once you set the center pin.. the plywood is never coming loose.. :no::no:

HD sells small packages of those pins.. try them out and see for yourself..

TIP.. take a flat head screwdriver and bang the sleeve into the wood.. hold in place and hit center pin with hammer.. 

The more you hit the head.. the tighter the anchor gets.. 

I also use them for mounting 1X4 wood for dryer receptacles..


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## HARRY304E

sbrn33 said:


> Na, I think it's an east coast thing.


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## B4T

Cletis said:


> It's cuz of the wicking/sponge effect


We don't have that problem on Long Island.. :no::no:


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## user4818

B4T said:


> Yes.. once you set the center pin.. the plywood is never coming loose.. :no::no:
> 
> HD sells small packages of those pins.. try them out and see for yourself..
> 
> TIP.. take a flat head screwdriver and bang the sleeve into the wood.. hold in place and hit center pin with hammer..
> 
> The more you hit the head.. the tighter the anchor gets..
> 
> I also use them for mounting 1X4 wood for dryer receptacles..


I've used them before and they work well. I ramset a few 2x4's in, screw the plywood to that and done. Whatever works.


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## HARRY304E

B4T said:


> Very true.. I have never seen a panel mounted directly to a concrete or block wall..
> 
> It does make for a better job using a 3/4" 2'X4' piece of plywood to mount the panel on..
> 
> HD sells them pre-cut.. you can't do any better than that.. :thumbsup:
> 
> I have seen a few hacks who are too cheap to buy 3/4".. so they buy (2) pieces of 1/2" plywood instead.. :no::no:


:thumbsup::thumbsup:


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## user4818

Harry is still shocked that the rest of the country uses uninsulated staples on romex.


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## eejack

Peter D said:


> Harry is still shocked that the rest of the country uses uninsulated staples on romex.


They make insulated staples?

What will these crazy kids think up next...


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## brian john

eejack said:


> They make insulated staples?
> 
> What will these crazy kids think up next...


And only acceptable on MC.:no::whistling2:


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## SVT CAMR

99% of the time I attach anything to concrete I use a 1/4" tapcon. Proper size bit and a 5/16" driver and they go right in.


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## HARRY304E

Peter D said:


> Harry is still shocked that the rest of the country uses uninsulated staples on romex.


Ah no!...


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## user4818

HARRY304E said:


> Ah no!...


Ah yes!


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## HARRY304E

Peter D said:


> Ah yes!


Ah why?:blink:


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## Magnettica

I prefer to drill 1 1/4" holes 3/4 of the way through a single 2' section of pt 2x4. Then a 1/4" hole the rest of the way through. Do this once to each 2x4 and mark the wall with a sharpie. Drill a hole 5/8" thick and install a 2.5" metal shield in both holes. Use 3" lag screws to attach the 2x4's to the wall. Use a 9/16 nut driver to tighten the lags. Be sure to center and level the board before attaching it to the wall studs. Guaranteed that board isn't going anywhere.


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## TOOL_5150

Magnettica said:


> I prefer to drill 1 1/4" holes 3/4 of the way through a single 2' section of pt 2x4. Then a 1/4" hole the rest of the way through. Do this once to each 2x4 and mark the wall with a sharpie. Drill a hole 5/8" thick and install a 2.5" metal shield in both holes. Use 3" lag screws to attach the 2x4's to the wall. Use a 9/16 nut driver to tighten the lags. Be sure to center and level the board before attaching it to the wall studs. Guaranteed that board isn't going anywhere.


nah, im not a carpenter.


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## BBQ

B4T said:


> I have never seen 2X4's mounted first and then plywood on top of that.. just a useless step.. IMO..


Ok got it, Painted plywood not useless, 2x4s useless B4T has spoken.


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## B4T

BBQ said:


> Ok got it, Painted plywood not useless, 2x4s useless B4T has spoken.


Thats right.. a useless step... NOBODY does it here.. so now you can say EVERYBODY here does it wrong because BBQ has spoken.. 

I hope I got it right.. and YES.. painted plywood is the way to go.. ESPECIALLY old grimy dirty plywood you are mounting a bunch of new electrical panels on..

Oh yes.. I mean the job Eric did.. looks great except the unpainted old wood.. 

But that is what separates others from the elite.. that little extra step.. :thumbsup:


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## BBQ

Dude, relax. Do what you like and what works for you. Just also accept we are all different. 

It's the same thing with drivers, anyone that drives faster than us is an idiot, anyone that drives slower than us is stupid. We always feel we are right. 

BTW, securing regular wood to cement is a building code violation, it is supposed to be pressure treated if in contact with cement.


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## erics37

B4T said:


> Oh yes.. I mean the job Eric did.. looks great except the unpainted old wood..
> 
> But that is what separates others from the elite.. that little extra step.. :thumbsup:


Don't forget that my unpainted old wood wall with brand new electrical stuff on it is at a fish plant. As in, tons and tons of dead smelly fish, hundreds of sea gulls hovering around, entrails all over the place.... as far as senses go, there are much more offensive things going on than unpainted plywood.

Besides, we've already had this discussion, and you didn't make any sense last time either :laughing:


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## Shockdoc

I buy a 4x8 of 3/4 for about $15 and cut into four sections, then use a ramset nail gun to shoot them in for panels. Paint is nice but I don't have the time or patience.


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## Shockdoc

Magnettica said:


> I prefer to drill 1 1/4" holes 3/4 of the way through a single 2' section of pt 2x4. Then a 1/4" hole the rest of the way through. Do this once to each 2x4 and mark the wall with a sharpie. Drill a hole 5/8" thick and install a 2.5" metal shield in both holes. Use 3" lag screws to attach the 2x4's to the wall. Use a 9/16 nut driver to tighten the lags. Be sure to center and level the board before attaching it to the wall studs. Guaranteed that board isn't going anywhere.


In my younger caring days I built one off the wall using 2x6s and a 2x4 to build out over in front of the sewer line. I just don't seem to care that much anymore, I'll mount it sideways.


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## Amish Electrician

Maybe we ought to ask: why did the practice of using plywood start? Well, let's hop into the 'wayback' machine.'

First off, building used to be made of real brick. Not today's factory-perfect little mud-colored cubs, but real brick. Every brick was somewhat different in size and shape, and the faces were anything but flat. Look at an older building if you doubt me; bring along a 4-ft. level as a straight edge and you can really see it. Having a perfectly flat surface for mounting your stuff is a big help.

Next, it wasn't long ago that service drops were made of multiple components. You didn't have the meter, the main, and the breakers all mounted in the same big box; no, you had multiple meters mounted apart from their disconnects, and a separate panel apart from those. I think you can see how having a common panel made ounting and piping everything a lot easier.

Finally, cordless hammer-drills have been readily available only since about 1990. How many anchors do you want to set, using a hammer and a 'star' drill?


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## erics37

Amish Electrician said:


> Maybe we ought to ask: why did the practice of using plywood start? Well, let's hop into the 'wayback' machine.'
> 
> First off, building used to be made of real brick. Not today's factory-perfect little mud-colored cubs, but real brick. Every brick was somewhat different in size and shape, and the faces were anything but flat. Look at an older building if you doubt me; bring along a 4-ft. level as a straight edge and you can really see it. Having a perfectly flat surface for mounting your stuff is a big help.


Kinda reminds me of trying to mount something on broken face cinder block which people seem to love around here


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## B4T

eejack said:


> They make insulated staples?
> 
> What will these crazy kids think up next...


Using insulated staples is the best defense against problems with AFCI breakers.. strange things can happen to NM after we install it.. :001_huh:


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## green light

B4T said:


> Not hammering the staples so hard that they f up the wire is the best defense against problems with AFCI breakers.. strange things can happen to NM after we install it.. :001_huh:


Fixed it for ya


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## B4T

green light said:


> Fixed it for ya


Nice try.. but you can't beat a tiny piece of plastic that separates the steel staple from the copper wire..


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## sbrn33

Amish Electrician said:


> Maybe we ought to ask: why did the practice of using plywood start? Well, let's hop into the 'wayback' machine.'
> 
> First off, building used to be made of real brick. Not today's factory-perfect little mud-colored cubs, but real brick. Every brick was somewhat different in size and shape, and the faces were anything but flat. Look at an older building if you doubt me; bring along a 4-ft. level as a straight edge and you can really see it. Having a perfectly flat surface for mounting your stuff is a big help.
> 
> Next, it wasn't long ago that service drops were made of multiple components. You didn't have the meter, the main, and the breakers all mounted in the same big box; no, you had multiple meters mounted apart from their disconnects, and a separate panel apart from those. I think you can see how having a common panel made ounting and piping everything a lot easier.
> 
> Finally, cordless hammer-drills have been readily available only since about 1990. How many anchors do you want to set, using a hammer and a 'star' drill?


This is a good post except 3/4 of the people on here don't know what a star drill is.
On the staple thing. Whatever to each their own. One way is no better than another, it's all in what you like.


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## eejack

B4T said:


> Nice try.. but you can't beat a tiny piece of plastic that separates the steel staple from the copper wire..


Gramps taught me to hang wire, not beat it into submission. I will look into these insulated staples - if they work like normal staples and add a touch of extra protection I cannot see the harm in them.


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## B4T

eejack said:


> Gramps taught me to hang wire, not beat it into submission. I will look into these insulated staples - if they work like normal staples and add a touch of extra protection I cannot see the harm in them.


The wire staples bend if you hit a knot or not squarely with a hammer.. 

AFCI breakers look for a reason to make your life miserable.. I just give them one less thing to nail me with..


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## frenchelectrican

sbrn33 said:


> This is a good post except 3/4 of the people on here don't know what a star drill is.
> On the staple thing. Whatever to each their own. One way is no better than another, it's all in what you like.


I have heard the star drill I grew up see my old man use that all the time so I know what it look like.

I will post the photo in case other readers wonding what the heck is that .,,,











Merci,
Marc


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## BBQ

I used a star bit with the first company I worked for. We would use it only on concrete block to install toggle bolts.

Fast forward to a day I was sent to fix a wall pack and my van was in for service. I had no hammer drill but there was an HD in the parking lot so I went and bought a star bit to do the job.


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## chicken steve

BBQ said:


> BTW, securing regular wood to cement is a building code violation, it is supposed to be pressure treated if in contact with cement.


 
so for similar reasons, would not nema1 equipment be prohibited as well?

~CS~


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## BBQ

chicken steve said:


> so for similar reasons, would not nema1 equipment be prohibited as well?



Feel free to use 4X equipment in those locations. :thumbsup:


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## BBQ

*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
or cutout box, and shall be mounted so there is at least
6-mm (1⁄4-in.) airspace between the enclosure and the wall
or other supporting surface. Enclosures installed in wet locations
shall be weatherproof. For enclosures in wet locations,
raceways or cables entering above the level of uninsulated
live parts shall use fittings listed for wet locations.

_Exception: Nonmetallic enclosures shall be permitted to
be installed without the airspace on a concrete, masonry,
tile, or similar surface._


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## chicken steve

most panels are mettalic, , i want to use nema 1 BBQ

no 1/4" bumps

unlessi introduce them....

kosher ? or not?

~CS~


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## BBQ

chicken steve said:


> no, i want to use nema 1 BBQ
> 
> kosher ? or not?
> 
> ~CS~


IMO yes.


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## BBQ

For the record, my own panel is mounted on painted plywood, but mounting the panels to the stone foundation would have been a bitch. :jester:


I built a stud wall from floor to joists with a 4 x 8 sheet of painted plywood hung sideways. It has a couple of panels and my cable / phone / data crap on it. Also a two head EBU.


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## B4T

Before plywood.. guys used to use scrap pieces of 1X6 siding with "cut nails"..

I remember using these nails as a helper mounting plywood and having it shatter in my face.. this was before safety glasses were common PPE..

The metal stuck in my forehead.. you never know when something so simple can go horribly wrong.. :no:


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## chicken steve

i guess that's one way to earn the term _metalhead_ B4T....~CS~


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## BBQ

B4T said:


> Before plywood.. guys used to use scrap pieces of 1X6 siding with "cut nails"..
> 
> I remember using these nails as a helper mounting plywood and having it shatter in my face.. this was before safety glasses were common PPE..
> 
> *The metal stuck in my forehead..*



This could explain so much. :laughing:


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