ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat Box
Recent Posts
HVDC Greece to Crete
by gfretwell - 08/06/20 02:28 AM
310.15 (B) 7 Feeders
by HotLine1 - 07/31/20 02:29 PM
What would be the ideal solution?
by Fleppin - 07/21/20 12:42 AM
NESC question
by gfretwell - 07/16/20 04:17 PM
Code Violation or just not good Practice?
by HotLine1 - 07/16/20 03:03 PM
New in the Gallery:
Facebook follies, bad wiring
FPE in Germany pt.2
Who's Online Now
0 registered members (), 13 guests, and 25 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Page 1 of 2 1 2
Horse Barn Wiring Methods #93735 06/08/05 07:15 PM
Joined: Jun 2004
Posts: 613
S
shortcircuit Offline OP
Member
Is romex (NM) allowed to be used in the walls and ceilings of a horse barn in areas specified by 547.1 where it will be concealed by a finish surface such as wood on the walls and plastered ceilings?

shortcircuit

2017 / 2014 NEC & Related Books and Study Guides
Re: Horse Barn Wiring Methods #93736 06/08/05 07:41 PM
Joined: Mar 2005
Posts: 212
G
Gregtaylor Offline
Member
The way I read it, I think you're OK.

Re: Horse Barn Wiring Methods #93737 06/09/05 02:02 PM
Joined: Jun 2004
Posts: 613
S
shortcircuit Offline OP
Member
Can anyone explain what the last sentance of 334.10(3) means or maybe have a link to such list as described?

"Cables shall be concealed within walls, floors, or ceilings that provide a thermal barrier of material that has at least a 15-minute finish rating as identified in listings of fire-rated assemblies."

My concern is if romex (NM) is concealed behind finish walls of wood on the interior of a horse barn, is the wood wall finish acceptable as a 15-minute fire-rated assembly?

shortcircuit

Re: Horse Barn Wiring Methods #93738 06/09/05 03:04 PM
Joined: Dec 2003
Posts: 751
E
earlydean Offline
Member
As I recall, 1/2 inch wallboard has a 15 minute rating.
Let me check the UL book for others.


Earl
Re: Horse Barn Wiring Methods #93739 06/09/05 03:17 PM
Joined: Dec 2003
Posts: 751
E
earlydean Offline
Member
Nope, no wood. All the listed assemblies are gypsum wallboard, plaster, cement block, masonry or 24 gauge metal panels.


Earl
Re: Horse Barn Wiring Methods #93740 06/09/05 03:19 PM
Joined: Dec 2003
Posts: 751
E
earlydean Offline
Member
Oh yeah, and concrete.


Earl
Re: Horse Barn Wiring Methods #93741 06/09/05 03:53 PM
Joined: Dec 2003
Posts: 751
E
earlydean Offline
Member
Now you got me going.

My rule of thumb is just not sufficient. the finish ratings go all over the chart, depending on the manufacturer and the product. Examples: American Gypsum Co. 5/8 inch Gypsum board Types AGX-1,2&3 have 23 minute finish ratings. AGX-5 has a 26 minute finish rating. US Gypsum Co. 1/2 inch Gypsum Wallboard (GWB) Types AR, FRX-G, SCX, SHX or WRX all have a 29 minute finish rating.
There are hundreds more. But, the lowest rating I could find for 1/2 inch GWB was 20 minutes. The rating for some 3/8 inch GWB was 8 minutes, so watch out!
The assembly also required paper tape over the joints, and usually a minimum of 2 coats of joint finishing compound.

Sounds like, to make your installation code compliant, you need to add 1/2 GWB over the walls of the barn where you have run the romex.


Earl
Re: Horse Barn Wiring Methods #93742 06/09/05 04:12 PM
Joined: Dec 2003
Posts: 751
E
earlydean Offline
Member
You can research them yourself at: http://www.ul.com/fire/building.html
Click on the picture of the front cover of the building materials directory.


Earl
Re: Horse Barn Wiring Methods #93743 06/09/05 04:15 PM
Joined: Dec 2003
Posts: 751
E
earlydean Offline
Member
http://database.ul.com/cgi-bin/XYV/...d=1074327030&cfgid=1073741824&ve rsion=versionless&parent_id=1073984818&sequence=1


Earl
Re: Horse Barn Wiring Methods #93744 06/09/05 04:58 PM
Joined: Jun 2004
Posts: 613
S
shortcircuit Offline OP
Member
Thanx earlydean, but I couldn't navigate through to where I could find specific listings on sheetrock and wood?

shortcircuit

Page 1 of 2 1 2

Featured:

2020 National Electrical Code
2020 National Electrical
Code (NEC)

* * * * * * *

2017 Master Electrician Exam Preparation Combos
2017 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Member Spotlight
pcsailor
pcsailor
Minneapolis, MN, USA
Posts: 21
Joined: September 2019
Show All Member Profiles 
Top Posters(30 Days)
BigB 3
Popular Topics(Views)
268,614 Are you busy
202,965 Re: Forum
191,341 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.7.3