Romex in an outside Gazebo

[jxofaltrds]

I live in Orange County CA an have wired 4 can lights in a Gazebo ceiling. The structure is separate from the house, has a roof and an enclosed ceiling... That is a tiled roof and tongue and groove wood covering the interior ceiling. My Romex is between the two surfaces. Anything exposed has been wired in a conduit. I have had the same city fail me twice now for using Romex to feed the can lights, even though it is fully encapsulated from physical damage and water. I was able to argue my way through it last time, but would like to know who's right. As far as being damp, it has no ability to get wet, no more than Romex inside an exterior wall covered with siding.
Thanks for your time-
Pete

Allowed. No NM but the cans are OK?????

(A) Type NM. Type NM cable shall be permitted as follows:
(1) For both exposed and concealed work in normally dry
locations except as prohibited in 334.10(3)

Based on his original argument that it's "no more than Romex inside an exterior wall covered with siding" the location is indeed dry by definition. Wonder what kind of conductors he had in the conduit.

Siding does not provide a normally dry location.

 

[mjf]

Allowed. No NM but the cans are OK?????

(A) Type NM. Type NM cable shall be permitted as follows:
(1) For both exposed and concealed work in normally dry
locations except as prohibited in 334.10(3)



Siding does not provide a normally dry location.

There must be hundreds of thousands of miles of illegally installed nm cable across the USA.

 

[GoldDigger]

Siding does not provide a normally dry location.

Does siding plus an air infiltration and water barrier (but not vapor barrier), such as Tyvek building wrap, create a normally dry location?

Tapatalk!

 

[jxofaltrds]

Does siding plus an air infiltration and water barrier (but not vapor barrier), such as Tyvek building wrap, create a normally dry location?

Tapatalk!

Yes but I can not find the ASTM standard to quote. I had it back in 2010 but some how lost it!!!!!!!:rant:

 

[mjf]

you're saying all the nm cable in exterior walls of my house (built in the 1890's and rewired over the years) is illegal because it's in a damp location?

Does that also mean no nm cable anywhere in an old house with a slate roof?

 

[jxofaltrds]

you're saying all the nm cable in exterior walls of my house (built in the 1890's and rewired over the years) is illegal because it's in a damp location?

Does that also mean no nm cable anywhere in an old house with a slate roof?

No one said exterior walls are damp or wet locations.

 

[jumper]

No one said exterior walls are damp or wet locations.

It seems to me that you kinda implied that here:

Siding does not provide a normally dry location

.

:? Or did I misinterpret what you meant?

 

[GoldDigger]

I think he may have been hinting that the gazebo siding (under the roof) may not have had the tar paper, plastic, or other accessories that allow a siding covered wall to be a dry area?)

Tapatalk!

 

[mjf]

I think he may have been hinting that the gazebo siding (under the roof) may not have had the tar paper, plastic, or other accessories that allow a siding covered wall to be a dry area?)

Tapatalk!

which in turn implies what I referenced about older houses without exterior (roofing and siding/sheathing) upgrades being in violation if the electric is upgraded using nm cable.

 

[jxofaltrds]

It seems to me that you kinda implied that here:

.

:? Or did I misinterpret what you meant?

You did not misinterpret - I misread or did not see "inside the wall"

My bad:slaphead:

 

[sparky=t]

damp location

damp location

my take is, if it leaves the envelope of the structure it is in a damp / wet location

 

[jxofaltrds]

http://forums.mikeholt.com/showthread.php?t=159472

334.10 Uses Permitted. Type NM, Type NMC, and Type
NMS cables shall be permitted to be used in the following:
(1) One- and two-family dwellings and their attached or
detached garages, and their storage buildings.

Is it a storage building? Probably not however what if they just covered the furniture and 'stored' it for the winter.

I would allow NM in the 'dry areas'.

 

[K8MHZ]

http://forums.mikeholt.com/showthread.php?t=159472

334.10 Uses Permitted. Type NM, Type NMC, and Type
NMS cables shall be permitted to be used in the following:
(1) One- and two-family dwellings and their attached or
detached garages, and their storage buildings.

Is it a storage building? Probably not however what if they just covered the furniture and 'stored' it for the winter.

I would allow NM in the 'dry areas'.

From 2008 NEC

(3) Other structures permitted to be of types III, IV and V construction.......

FPN No. 2: See Annex E for determination of building types.

I could see this as a 'non-rated' Type V structure.

 

[jxofaltrds]

From 2008 NEC

(3) Other structures permitted to be of types III, IV and V construction.......

FPN No. 2: See Annex E for determination of building types.

I could see this as a 'non-rated' Type V structure.

Yes that is a stronger argument. And probably a better here's the code Mr. Inspector. :thumbsup:

 

[Ponchik]

OP, when you failed the inspection, did you ask for a NEC code reference or did the inspector show you in the NEC ????

Always ask for a NEC code reference and read it and see what it actually says and does it really apply to your installation.

 

[renosteinke]

Household siding does not make a wall cavity sufficiently 'dry' for NM-B?

In that cast, Chicago -almost alone- has had it right all along. Only pipe will do. That NM stuff, it seems, can't be used anywhere ... not even inside a submarine. After all, another thread has educated us about "boat cable!"

(Submarines are really 'pleasure craft,' according to jokes told by the rest of the Navy).

 

[RASanders]

15-minute "thermal" barrier?

15-minute "thermal" barrier?

...4 can lights in a Gazebo ceiling (let's assume these are outdoor soffit/damp rated)...structure separate from the house...tiled roof and tongue and groove wood covering the interior ceiling...Romex between the two...Anything exposed has been wired in conduit...fully encapsulated from physical damage and water.//...conduit to first box is PVC...wire is THHN...Romex starts from that box, in ceiling covered by wood...set for a photocell at finish.
- Pete

SO; if I understand this correctly for my own future reference:
From NEC-2011
334.10 Uses Permitted.
Type NM, Type NMC, and Type NMS cables shall be permitted to be used in the following:
(3) Other structures permitted to be of types III, IV and V construction...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.

Info-Note No.2 See Annex E for determination of building types [NFPA 220, Table 3-1]

Type V(000) is "wood frame" with non-rated (no fire-resistive requirements), which applies to this detached gazebo, which also allows some or all of the structural elements to be combustible (wood).

A wood tongue-in-groove ceiling in a wood gazebo permitted by the local building code sounds fine, but I am wondering about proving this 15-minute "thermal" barrier. Should be easy, right?

IBC-TABLE 721.6.2(1) TIME ASSIGNED TO WALLBOARD MEMBRANES
Includes an entry for: 19/32-inch wood structural panel bonded with exterior glue = 15 minutes
...but that appears to apply directly to walls, not to wood ceilings.

What I did not find through cursory review of online search results, was any 3rd-party certified test result chart of some code-accepted method to determine the fire-resistance rating of a wood ceiling of particular varieties (each tree is slightly different) with the "resistive membrane" (in this case T&G wood, of unknown type) directly applied to the exposed surface of the wood structural elements.

I found one independent report online at American Wood Council: http://www.awc.org/pdf/WDF19-2_White.pdf
which listed a Table 1 showing a component-additive method that assigned a 15 minute resistive time to 5/8-inch thick Douglas-fir plywood, seemingly inline with the IBC wallboard time.
Surely a similar or thicker T&G (typically 3/4") would be as-resistive or better, without having to add insulation between the ceiling framing for additional fire-resistive ratings? Not specifically noted, but should be available from some reference somewhere, is the time assigned to UL "FR-S" rated wood products, or other "Fire Resistive Treated Lumber."

As an example, I found articles for "TimberSIL" - apparently some kind of silicate/glass-reinforced wood treatment, which can come in T&G panels - specifically tested as a rated Class A fire/ignition resistant ceiling decking approved in California for ceilings of outdoor patio structures in high fire vulnerability areas.

Does anyone else have a more specific easy-to-find PDF specifically stating "yep, any 5/8-inch or thicker T&G, (or maybe FR-treated 1/2-inch or thicker T&G, etc.) is a 15-minute thermal barrier that protects NM cabling from any further requirements"? :?

 

[mgookin]

SO; if I understand this correctly for my own future reference:
From NEC-2011
334.10 Uses Permitted.
Type NM, Type NMC, and Type NMS cables shall be permitted to be used in the following:
(3) Other structures permitted to be of types III, IV and V construction...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.

Info-Note No.2 See Annex E for determination of building types [NFPA 220, Table 3-1]

Type V(000) is "wood frame" with non-rated (no fire-resistive requirements), which applies to this detached gazebo, which also allows some or all of the structural elements to be combustible (wood).

A wood tongue-in-groove ceiling in a wood gazebo permitted by the local building code sounds fine, but I am wondering about proving this 15-minute "thermal" barrier. Should be easy, right?

IBC-TABLE 721.6.2(1) TIME ASSIGNED TO WALLBOARD MEMBRANES
Includes an entry for: 19/32-inch wood structural panel bonded with exterior glue = 15 minutes
...but that appears to apply directly to walls, not to wood ceilings.

What I did not find through cursory review of online search results, was any 3rd-party certified test result chart of some code-accepted method to determine the fire-resistance rating of a wood ceiling of particular varieties (each tree is slightly different) with the "resistive membrane" (in this case T&G wood, of unknown type) directly applied to the exposed surface of the wood structural elements.

I found one independent report online at American Wood Council: http://www.awc.org/pdf/WDF19-2_White.pdf
which listed a Table 1 showing a component-additive method that assigned a 15 minute resistive time to 5/8-inch thick Douglas-fir plywood, seemingly inline with the IBC wallboard time.
Surely a similar or thicker T&G (typically 3/4") would be as-resistive or better, without having to add insulation between the ceiling framing for additional fire-resistive ratings? Not specifically noted, but should be available from some reference somewhere, is the time assigned to UL "FR-S" rated wood products, or other "Fire Resistive Treated Lumber."

As an example, I found articles for "TimberSIL" - apparently some kind of silicate/glass-reinforced wood treatment, which can come in T&G panels - specifically tested as a rated Class A fire/ignition resistant ceiling decking approved in California for ceilings of outdoor patio structures in high fire vulnerability areas.

Does anyone else have a more specific easy-to-find PDF specifically stating "yep, any 5/8-inch or thicker T&G, (or maybe FR-treated 1/2-inch or thicker T&G, etc.) is a 15-minute thermal barrier that protects NM cabling from any further requirements"? :?

Yes. Look in your building code for "calculated fire resistance" where they have a table of construction materials and their values, in minutes.