How can I pass my home inspection? (fire inspector)

April 22, 2008 4:33 PM

I need to install some fireblocks (aka fire stops AND fire block[ing]) in my basement. What can I use to make these? Can I use regular sheetrock to make these or do they have to be some special type of sheetrock? If I can't use sheetrock, what type and thickness of wood do they need to be?
posted by tickettrader to home & garden (9 comments total)

The answer will probably depend on your county or state building code. Your profile says "USA", but you might need to be more specific to get a better answer.

As a general rule, though, sheetrock should work. Depending on the location and application, sheet metal could work too - that's what they used as a fireblock when I had my furnace replaced.
posted by gwenzel at 5:00 PM on April 22, 2008

Not nearly enough information to give any kind of mildly accurate answer here…and even if one thinks one can, inspectors are free to reinterpret any part of the code in all manner of…manners. Sure, you could try fighting that…good luck! While many people use the terms fire blocking and fire stopping interchangeably (including many code books) your question suggests that you need some good old-fashioned "draft stopping" in cavities and some fire stopping at penetrations. I could not even begin to guess what circumstances you might have in place, but I do happen to have a copy of the 2003 IRC in front of me…click through to profile…you know the rest. (Also, the usual "IANYAAEIIW, IWNGYAABITWTBITDWWP. ASMTNBHL." applies.)
posted by Dick Paris at 5:04 PM on April 22, 2008

As far as I've heard the term "fireblocking" used, dimensional lumber is okay. Like, if you have a 2x6 light framed wall that's tall enough that it needs a fireblock, you just put a horizontal 2x6 in all the bays between studs. But, that's type V-NR construction.

I'll go look up fireblocking in my 2007 California Building Code, though.
posted by LionIndex at 5:17 PM on April 22, 2008

Directly from the current California code to you:

Section 717.2.1: Fireblocking Materials
Fireblocking shall consist of 2-inch nominal lumber or two thicknesses of 1-inch nominal lumber with broken lap joints or one thickness of 0.719-inch wood structural panel or one thickness of 0.75-inch particle board with joints backed by 0.75-inch particle board. Gypsum board, cement fiber board, batts or blankets of mineral wool, glass fiber or other approved materials installed in such a manner as to be securely retained in place shall be permitted as an acceptable fireblock. Batts or blankets of mineral or glass fiber or other approved nonrigid materials shall be permitted for compliance with the 10-foot horizontal fireblocking in walls constructred using parallel rows of studs or staggered studs. Loose fill insulation material shall not be used as a fireblock unless specifically tested in the form and manner intended for use to demonstrate its ability to remain in place and to retard the spread of fire an hot gases. The integrity of fireblocks shall be maintained.

Since the code says "any other approved materials", your fireblocks basically need to be anything listed specifically above, or anything else that your inspector will let you call a fireblock.
posted by LionIndex at 5:25 PM on April 22, 2008

Thanks LionIndex.

I'm going to put in the sheetrock and if it fails inspection, at least I'll have the inspector 'trapped' in my basement and can ask him questions then.
posted by tickettrader at 6:30 PM on April 22, 2008

You'll also need to have some fire approved caulking on hand to fill any gaps.
posted by Gungho at 8:11 PM on April 22, 2008

5/8" Type X Sheetrock or 1/2" Type C sheetrock are fire rated, I believe for 1 hour - up here in Ontario anyway. That's probably not the whole story.

Contact a local architect, they will know what the code is for your area, and what materials they can recommend. Fire rating is not something to play around with.
posted by defcom1 at 9:32 PM on April 22, 2008

5/8" Type X Sheetrock or 1/2" Type C sheetrock are fire rated, I believe for 1 hour - up here in Ontario anyway. That's probably not the whole story.

Contact a local architect, they will know what the code is for your area, and what materials they can recommend. Fire rating is not something to play around with.

Yeah, gyp board gets the same rating down here too, but what we're dealing with in fireblocking isn't necessarily installing a fire-rated barrier. All fireblocking is meant to do is separate cavity spaces from one another so that fire and smoke don't spread really easily throughout a building through the walls and attics. As Dick Paris mentioned, it's really more of a "draft stop" than a fire-rated barrier.
posted by LionIndex at 7:41 AM on April 23, 2008

LionIndex writes "Since the code says 'any other approved materials', your fireblocks basically need to be anything listed specifically above, or anything else that your inspector will let you call a fireblock."

Far and away the fastest, easiest method is use of a FireBlock rated foam. Especially if this is a retrofit. If you go this route invest the 30-70 dollars in the gun system if you need more than a can or two; well worth the cost because of the much greater control of foam placement IMO.
posted by Mitheral at 9:38 AM on April 23, 2008