Walls and Wiring

[Guest]

Re: Walls and Wiring

Regardless of any requirement, most platform type framing in theory does provide a 20-minute rating. It would be prudent, even if not required, to try and maintain that 20-minute rating whenever possible. You may not be bound by fire-rated foams, but you may reap a benefit.

If there is any balloon framing, there would have to be blocking at each level to create a 20-minute rating. Any holes in those blocks would have to be sealed to maintain the 20-minute rating. There may be other weak links in the wall assembly that undermine the 20-minute rating-- and no amount of foam or sealant is going to make those go away.

The home center foam (expanding type or non-expanding type) will create a draft seal, but it might not maintain the 20-minute wall assembly.

In summary, I personally would strive to maintain the 20-minute rating even if not required. 20-minutes isn't much, but it's better than nothing.

 

[ryan_618]

Re: Walls and Wiring

Fire blocking is required in combustible, concealed constrcuction to prevent the passage of flame from the vertical to the horizontal, and also between floors. Regardless of the fire-resistance rating.

Expanding foam does not achieve this unless it has passed the ASTM E119 standard, or other equivalant and approved.

Sorry, Roger, but I'm with Pierre on this one.

 

[roger]

Re: Walls and Wiring

Ryan, I'll buy it when I see a code reference pointing to an approved fire caulk.

Please note that I have never said the means to seal these penetrations could be done with a flammable means be it foam, paper, or whatever.

We normally use a cheap latex caulk, and I can't tell you if it meets any standard at the moment.


Roger

 

[roger]

Re: Walls and Wiring

William, most expandable foams are combustible at relatively low temperatures and shouldn't be used.

I do know this information is on the product.

Roger

 

[pierre]

Re: Walls and Wiring

Hello Scott W
I don't recall mentioning "envelope" in this thread, that is an aspect of the Energy Conservation Construction Code of NY State, Section 502. But I will not go there in this thread as that is "thread drifting" and I do not want to do that .

As for fireblocking/firestopping code citation for NY :

R602.8 Fireblocking required.
Fireblocking shall be provided to cut off all concealed draft openings (both vertical and horizontal) and to form an effective fire barrier between stories, and between a top story and the roof space. Fireblocking shall be provided in wood-frame construction in the following locations.
1. In concealed spaces of stud walls and partitions, including furred spaces, at the ceiling and floor levels. Batts or blankets of mineral or glass fiber shall be allowed as fireblocking in walls constucted using parallel rows of studs or staggered studs.
(there are more locations - stairs- soffits, etc..., but I will keep this short)

R602.8.1.2 Fireblocking integrity.
The integrity of all fireblocks shall be maintained.

When drilling through these plates for wiring in NY State, approved firestopping is required to maintain the integrity as per R602.8.1.2.

As I have mentioned there are multiple ways to accomplish this.

Pierre

 

[ryan_618]

Re: Walls and Wiring

Roger: The reference Pierre lists is not only from the NY building code, but also the International Residential code.

 

[roger]

Re: Walls and Wiring

Ryan, I still don't see anything or any standard specified.

Per the wording it is even allowing plane jane fiberglass to achieve this.

Roger

 

[hurk27]

Re: Walls and Wiring

I'm not sure if this applys but it only says fire-resistant-rated walls. Then partitions, floors, or ceilings. Does this mean that the latter is not fire-rated just the walls?


300.21 Spread of Fire or Products of Combustion.
Electrical installations in hollow spaces, vertical shafts, and ventilation or air-handling ducts shall be made so that the possible spread of fire or products of combustion will not be substantially increased. Openings around electrical penetrations through fire-resistant-rated walls, partitions, floors, or ceilings shall be firestopped using approved methods to maintain the fire resistance rating.

FPN: Directories of electrical construction materials published by qualified testing laboratories contain many listing installation restrictions necessary to maintain the fire-resistive rating of assemblies where penetrations or openings are made. Building codes also contain restrictions on membrane penetrations on opposite sides of a fire-resistance?rated wall assembly. An example is the 600-mm (24-in.) minimum horizontal separation that usually applies between boxes installed on opposite sides of the wall. Assistance in complying with 300.21 can be found in building codes, fire resistance directories, and product listings.
725.61(B) Riser.
(2) Other cables as covered in Table 725.61 and other listed wiring methods as covered in Chapter 3 shall be installed in metal raceways or located in a fireproof shaft having firestops at each floor.

This is repeated in the other chapters for other types of cable/ fiber optics

[ December 08, 2003, 01:33 AM: Message edited by: hurk27 ]

 

[eprice]

Re: Walls and Wiring

William,

if the IRC has been adopted in your area, Section 602.8 covers the areas where fireblocking is required. This section is very similar to equivalent sections in the IBC and UBC. Section 602.8.1 lists the materials that may be used for fireblocking. I don't see spray foam insulation listed there, though fiberglass insulation is. Actually, in the situations you mentioned, I believe the 2x plate would be the fireblock, and IRC section 602.8.1.2 requires the integrity of this fireblock to be maintained. hence the requirement for caulk in the drilled holes.

When you say "wire" are you talking about NM cable? If so, I think the requirement for listed firecaulk comes from the fact that in a fire situation the jacket and insulation will melt and the only way to maintain the integrity of the fireblock is with the use of an intumiscient (SP?) caulk that will expand to fill the void left by the melted jacket and insulation.