722.6 Calculated Fire Resistance (Resilient channel)

[rosegamble]

Hi, everyone. I tend to use 722 for fire-resistance rated wood assemblies.

Firstly, one thing I cannot figure out is whether adding resilient channel decreases or increases the rating that I am manually calculating. Anyone know?

Separately, 722.6.2(5) addresses insulation. If the insulation is not one of these kinds specified, does that also affect the rating one way or the other?

Lastly, where do you all like to go for UL-approved assemblies? USG's website comes to mind, but I haven't had much luck finding others.

Thanks!

 

[RLGA]

Theoretically, resilient channels would increase the rating since the thermal transmission would be reduced. However, how much the rating is increased is not determined, and Section 722 does not address it; thus, you cannot consider the resilient channels when using the calculated fire-resistance provisions. You can, however, submit a code modification for an alternative material according to IBC Section 104.11. It may be considered if your wall assembly falls short of the maximum 1-hour rating by a few minutes.

To get credit for insulation, you must provide the type of insulation indicated. Again, you may submit a code modification to allow other insulating materials, especially if you can show their use in tested assemblies.

To get UL assemblies, go to UL directly: https://productiq.ulprospector.com/en. Join the Product IQ website, and you will have access to all of UL's information (except for UL testing standards).

 

[rosegamble]

Theoretically, resilient channels would increase the rating since the thermal transmission would be reduced. However, how much the rating is increased is not determined, and Section 722 does not address it; thus, you cannot consider the resilient channels when using the calculated fire-resistance provisions. You can, however, submit a code modification for an alternative material according to IBC Section 104.11. It may be considered if your wall assembly falls short of the maximum 1-hour rating by a few minutes.

To get credit for insulation, you must provide the type of insulation indicated. Again, you may submit a code modification to allow other insulating materials, especially if you can show their use in tested assemblies.

To get UL assemblies, go to UL directly: https://productiq.ulprospector.com/en. Join the Product IQ website, and you will have access to all of UL's information (except for UL testing standards).

Thank you, as always!

(1) Resilient channel - I just wanted to ensure it doesn't REDUCE the rating somehow. Not so important to know its rating contribution since I don't need to add more time to the assembly.

(2) Insulation. Same as above. If it's not one specified, I guess there's no way of knowing if it hurts the assembly.

(3) Assemblies - thank you!

(4) Anyone know what the rating of a metal stud wall is? I know a wood 2x4 wall is 20 minutes if spaced 16" on center. The steel section 722.5 doesn't cover metal studs I believe.

 

[RLGA]

(4) Anyone know what the rating of a metal stud wall is? I know a wood 2x4 wall is 20 minutes if spaced 16" on center. The steel section 722.5 doesn't cover metal studs I believe.

Nope, and neither does the IBC, which is why Section 722 does not address metal stud assemblies...yet. I assume they will eventually include metal studs in the section, but someone needs to conduct the research to create substantiating evidence to support assumptions.

However, plenty of tested UL assemblies cover just about every conceivable situation you can imagine. You can also look at GA-600. Find a "Generic" assembly and use that, or find a "Proprietary" assembly, look to see if it was tested per UL, and, if so, use that UL assembly instead of the GA-600 assembly since the IBC limits the use of GA-600 to only the generic assemblies.

Both the UL and GA have conditions that can modify the indicated assembly. For example, you can increase the stud depth and thickness, add additional layers of gypsum board, and even add a layer of plywood on top of or behind a layer of gypsum board.

 

[rosegamble]

Nope, and neither does the IBC, which is why Section 722 does not address metal stud assemblies...yet. I assume they will eventually include metal studs in the section, but someone needs to conduct the research to create substantiating evidence to support assumptions.

However, plenty of tested UL assemblies cover just about every conceivable situation you can imagine. You can also look at GA-600. Find a "Generic" assembly and use that, or find a "Proprietary" assembly, look to see if it was tested per UL, and, if so, use that UL assembly instead of the GA-600 assembly since the IBC limits the use of GA-600 to only the generic assemblies.

Both the UL and GA have conditions that can modify the indicated assembly. For example, you can increase the stud depth and thickness, add additional layers of gypsum board, and even add a layer of plywood on top of or behind a layer of gypsum board.

Got it. Thank you!