• Welcome to The Building Code Forum

    Your premier resource for building code knowledge.

    This forum remains free to the public thanks to the generous support of our Sawhorse Members and Corporate Sponsors. Their contributions help keep this community thriving and accessible.

    Want enhanced access to expert discussions and exclusive features? Learn more about the benefits here.

    Ready to upgrade? Log in and upgrade now.

Electric Cables around top plate

Uncle Bob

REGISTERED
Joined
Oct 17, 2009
Messages
1,409
Location
Texas
I haven't seen this before. The electrical installers; cut out the exterior osb and ran the cables around the top plate; instead of through the top plate.



(right click on picture to enlarge)

Uncle Bob
 
interesting.........how do you secure the cables correctly? Wouldn't work here, by the time you get the blocking in there to properly secure the cables, you are taking up insulation space the the IECC requires.
 
I've seen it two or three times here (two or three different contractors)..... after changing it out the electrical contractors no longer do it this way.
 
Never seen it done that way, in a fire I would think the soffit will be a straw. A hole counts as a staple right? That's a double hole, get your fire

caulk out!

pc1
 
* $ *

In addition to the above comments, ...wonder how they are going

to comply with Section R703 - Wall Covering [ i.e. - "exterior walls shall provide

the building with a weather resistant wall envelope." ] ?

$ * $
 
Last edited by a moderator:
Okay...gonna play devils advocate

fatboy said:
interesting.........how do you secure the cables correctly? Wouldn't work here, by the time you get the blocking in there to properly secure the cables, you are taking up insulation space the the IECC requires.
In the picture it appears that the cables are going through the top of the panel in and are secured properly..at the box. Usually service panels are located only a couple of feet from the top plate sooooo it is possible that the wires are secured above within 4.5 feet of the panel.

chris kennedy said:
What is the finish on the outside? Looks like the cables could catch a nail in a heartbeat if siding is applied.
With any overhang at all there will not be any siding in that location. Overhangs typically in this area of the country are usually 16" to 24" putting the siding about a foot below the top plate.

Pcinspector1 said:
Never seen it done that way, in a fire I would think the soffit will be a straw. A hole counts as a staple right? That's a double hole, get your fire caulk out! pc1
One of the allowed uses for draft stopping is insulation. Since this is an exterior wall...insulation will be placed over the hole toprovide draft stopping.

dcspector said:
What about 300.4(A)(1) and 334.30
300.4(A)(1)

(1) Bored Holes. In both exposed and concealed locations, where a cable- or raceway-type wiring method is installed through bored holes in joists, rafters, or wood members, holes shall be bored so that the edge of the hole is not less than 32 mm (1¼ in.) from the nearest edge of the wood member.

I would not consider this application to fit any of the specified locations.

334.30 Securing and Supporting.

Nonmetallic-sheathed cable shall be supported and secured by staples, cable ties, straps, hangers, or similar fittings designed and installed so as not to damage the cable, at intervals not exceeding 1.4 m (4½ ft) and within 300 mm (12 in.) of every outlet box, junction box, cabinet, or fitting. Flat cables shall not be stapled on edge.

See my first comment to fatboy

north star said:
* $ *In addition to the above comments, ...wonder how they are going

to comply with Section R703 - Wall Covering [ i.e. - "exterior walls shall provide

the building with a weather resistant wall envelope." ] ?

$ * $
This is above the "weather resistant envelope". As stated above it is typical in this area of the United States to have a 16" to 24" overhang. Thus putting the soffit below the holes in the osb is where the weather resistant envelope is protected by the soffit out to the facia.

Okay discussion????? Slams??????? Comments????????
 
From a structural standpoint I think going through the sheathing is better than going through the plates.

I am glad no one mentioned derating.
 
Mule,

You are correct! Insulation will fill the wall area covering the big holes in the OSB, I can go with that. And GH has a good point, I sometimes see the electricians hack out the plates!

Pc1
 
* * *

"Devils Advocate",

This is above the "weather resistant envelope". As stated above it is typical in this area of the United States to have a 16" to 24" overhang. Thus putting the soffit below the holes in the osb is where the weather resistant envelope is protected by the soffit out to the facia.
Can you please cite a code section where the exterior sheathing is "typically" not

required to be installed up to the top plates, ...in your area or another area of the

country? Simply because it is "typically" performed that way in a certain area,

does not mean it is approved. :D

* * *
 
I can't find where it IS required to be up to the top plate. R703.1 says it has to be "behind the exterior veneer". I realize 703.2 says it has to be applied over studs or sheathing of all exterior walls, but once the soffit overhang is boxed in, is the portion of the wall that extends above the bottom of the soffit considered an exterior wall? If you go to the definition of EXTERIOR WALL, it gives an example of a wall enclosing a mansard roof as being an exterior wall. That means the wall behind the mansard is not considered an exterior wall and I believe the portion of the wall behind the soffit overhang is the same type of example. But I am not the AHJ over it.
 
* * *

To all:

If we can set the "code requirements" aside for a moment, ...would

you accept this if it were your own house?

If "yes", ...o.k., it's your house. If "no", please explain why not.

Thanks!

Mule,

Also, if it is "typically" accepted to not install the exterior wall sheathing

[ in your area ] over the top plates, ...are the framers / carpenters

complying with Note " j " from Table R703.4 [ From the 2006 IRC. ] ?

"Note " j " - "Wood board sidings applied vertically shall be nailed to

horizontal nailing strips or blocking set 24 inches on center. Nails shall

penetrate 1½ inches into studs, studs and wood sheathing combined, or

blocking. A weather-resistive membrane shall be installed weatherboard

fashion under the vertical siding unless the siding boards are lapped or

battens are used."

* * *
 
Last edited by a moderator:
If this is inside the thermal envelope I would refer to:

N1102.4.1 Building thermal envelope. The building thermal envelope shall be durably sealed to limit infiltration. The sealing methods between dissimilar materials shall allow for differential expansion and contraction. The following shall be caulked, gasketed, weatherstripped or otherwise sealed with an air barrier material, suitable film or solid material.

Insulation is not an air barrier material.

Also, refer to the NM-B cable in damp locations thread [evil grin]

Tim
 
Oh gee Thanks for letting us all know what the section numbers actually read that I posted. We know what the code reads Mr Mule/ Moderator. Yes they do pertain to this install per the picture I have and can see.
 
I don't see how those cables are remotely properly supported OR protected from damage... the sheathing is going to damage itself everytime wind moves the wall.
 
north star said:
* * *"Devils Advocate",

Can you please cite a code section where the exterior sheathing is "typically" not

required to be installed up to the top plates, ...in your area or another area of the

country? Simply because it is "typically" performed that way in a certain area,

does not mean it is approved. :D

* * *
The framers do go all the way to the top plate. I'm trying to say that where the eave turns out could be part of the envelope...therefore cutting a hole in the osb is not part of the envelope...????????

north star said:
[Mule,Also, if it is "typically" accepted to not install the exterior wall sheathing

[ in your area ] over the top plates, ...are the framers / carpenters

complying with Note " j " from Table R703.4 [ From the 2006 IRC. ] ?

"Note " j " - "Wood board sidings applied vertically shall be nailed to

horizontal nailing strips or blocking set 24 inches on center. Nails shall

penetrate 1½ inches into studs, studs and wood sheathing combined, or

blocking. A weather-resistive membrane shall be installed weatherboard

fashion under the vertical siding unless the siding boards are lapped or

battens are used."

* * *
See above answer....and not much siding in our area, however when we do see siding it is usually lap siding and the siding terminates under the eave.

dcspector said:
Oh gee Thanks for letting us all know what the section numbers actually read that I posted. We know what the code reads Mr Mule/ Moderator.
dcspector, I don't understand where the attitude is coming from.

dcspector said:
Yes they do pertain to this install per the picture I have and can see.
That may be your opinion but it might not be everyones opinion. From my post on section....300.4(A)(1)

bored holes in joists, rafters, or wood members, I'm not about to post the entire section again! :)

In the picture the electrician did not bore a hole in a joist, rafter, or wood member in my opinion.

dcspector said:
We know what the code reads Mr Mule/ Moderator.
In my opinion posting sections of the code helps in providing particular phrases that may make for better discussion. Others may want to use other code sections for rebuttal.

Were you offended by me posting what the code specified?
 
Back
Top