JOIN DIYCHATROOM TODAY!

Maintenance 6 · 05-12-2009, 08:27 AM

The blue can does not have a UL rating. If the building inspector is telling you to use a product without a proper rating or UL listing in place of one that does, then he is setting himself up for a great deal of liability, regardless of what your torch test shows. Unscientific tailgate product tests performed by amatuer fire protection specialists don't hold up in court. Insurance companies love those. They can weasel out of a claim easier when a homeowner uses an untested, unrated product in place of the proper one. On the other hand, if you had a problem. you might be able to sue the inspector for having told you to use the wrong product.

Clutchcargo · 05-12-2009, 08:40 AM

That's a good point about the UL listing. The next time I see the inspector, I'm going to ask him about that.

**thekctermite** · 05-12-2009, 09:22 AM

Maintenance 6 is 100% right, your inspector is wrong in giving the option he's giving. Listings, my friend. Listings.

tjeieio · 06-04-2009, 02:37 PM

Okay - I have read this entire thread and have learned a great deal. Thanks for posting the excellent photos. One thing I have not fully understood is how to install the vertical @ 10' blocking. I have a 1" gap between my concrete basement wall and the 2x4 framing. If I stuff fiberglass insulation or rock wool behind one of the studs, how is that supposed to stay there? On the other hand, if I use P/T lumber or green sheetrock, how does this create a tight fit? Thanks in advance.

**thekctermite** · 06-05-2009, 09:44 AM

Quote:

Originally Posted by tjeieio

Okay - I have read this entire thread and have learned a great deal. Thanks for posting the excellent photos. One thing I have not fully understood is how to install the vertical @ 10' blocking. I have a 1" gap between my concrete basement wall and the 2x4 framing. If I stuff fiberglass insulation or rock wool behind one of the studs, how is that supposed to stay there? On the other hand, if I use P/T lumber or green sheetrock, how does this create a tight fit? Thanks in advance.

You've got a couple options when doing this.

The first is to use unfaced fiberglass insulation. Roll it up and pack it in very tight. When packed in it definitely won't go anywhere. Rock wool is pretty tough to pack in comparatively, unless you use something to retain it. In my experience most jurisdictions will allow fiberglass, since the code allows it in other fireblocking applications.

As you mentioned the other option is to use another piece of wood. Personally I wouldn't necessarily use treated material. Regular untreated 2x dimension lumber is fine, assuming it doesn't physically make contact with the concrete. Either wood you choose, there will be a bit of a gap...Perhaps less than 1/8". Such gaps MUST be sealed tight with orange fireblocking foam, which does a good job of bridging the gap.

tjeieio · 06-05-2009, 11:09 AM

Thanks for the quick reply. It makes some sense now. Hopefully our building dept will okay the fiberglass use. Waiting for my plan review.

avshockey · 07-19-2009, 10:25 PM

I wish I would have stumbled upon this before I started to frame my basement. I have some questions on the best way to fireblock my basement. I had blanket insulation on my foundation walls. When I framed my perimeter walls, I failed to get the wall as tight as I would have liked to the blanket insulation. The result is anywhere from a .25 to 2 inch gap behind my studs and a gap behind the top plate. What would be the easiest method to fireblock this dead space? I was thinking of just buying thicker bat fiberglass insulation for between the studs to take up that extra space. Does that count for fireblock to stop fire from going vertical or horizontal? Or do I still need wood or insulation wedged in behind the top plate and behind a stud every 10' horizontally?
I also have a soffit and reading this thread I will need to 2X block between the studs to keep a fire from rolling from vertical to horizontal in the soffit. However, do I have to block the joist spaces where my soffit
meets the ceiling (where the red X's are)?

tjeieio · 07-20-2009, 01:07 AM

Turns out the city is requiring R-21 insulation in my perimeter walls, plus waterproofing. As such, the 1 inch gap will be filled tightly with the fiberglass batts (3 1/2" studs plus 1 inch = 4 1/2") since the batts are 5 1/2" thick. Telephone conversations suggest this will suffice for horizontal blocking. Vertical blocking will still require the insulation to be installed between floor joists and above the top plate.

**thekctermite** · 07-20-2009, 09:20 AM

Avshockey-

The joists above your soffit do not require fireblocking. You can insulate them if you wish though. Blocking the stud spaces from opening up into the soffit is required, as stated.

The gap between the foundation wall and the framed wall at the top plate is a judgement call. I would require that you pack the gap at the plateline with fiberglass. Simply using thicker batts fills the gap at the stud spaces but not behind the studs themselves. I'd suggest packing it with fiberglass just to be safe.

**thekctermite** · 11-29-2009, 05:51 PM

Jeez, nearly 16,200 views on this thread in less than 10 months. Glad you all are reading up on fireblocking! One of these days I'll get a chance to expand it a little bit with more info....

GBR in WA · 11-29-2009, 07:33 PM

Great job, Kc! I'm all for being safe, and hope more people read your posts. I use page #4: http://www.codecheck.com/cc/images/CC5thEdSample.pdf Your posts explain things a lot better for those not in the building trade using the "language".
Keep up the good work!

Be safe, Gary

44070dart · 12-03-2009, 06:09 PM

I also stumbled upon this and had to do some back tracking on my basement finishing project ...I'm not a carpenter by any means { mechanic by trade } but I can read and have used a good remodeling book to help my project along but fireblocking wasn't explained anywhere as well as this thread .. thank you kc for the time it took to post this

**thekctermite** · 12-19-2009, 08:53 PM

Quote:

Originally Posted by 44070dart

I also stumbled upon this and had to do some back tracking on my basement finishing project ...I'm not a carpenter by any means { mechanic by trade } but I can read and have used a good remodeling book to help my project along but fireblocking wasn't explained anywhere as well as this thread .. thank you kc for the time it took to post this

You're welcome! Glad it was of some help to you on your project.

ssmith147 · 12-31-2009, 07:42 AM

Wow, am I glad I read this thread before proceeding with my basement finish.

I have a question concerning soffits that I'm not sure has been answered, though (if it has, I apologize- there's a lot here).

I have to build soffit in my basemenbt around the HVAC, plumbing, gas line, and wiring. On one end of my basement the soffit will run up against the concrete, while on the other end it will drop down through the middle of the living space, butting up to the concrete on one end (clearance is not an issue).

I know the 2x stud cavities need to be fireblocked from the soffit. Do I need to fireblock the joists above? Using sheetrock/insulation/foam seems to be the only way to jigsaw the solution into place. It won'tbe impossible and I've already got some ideas on how to proceed with each challenge. Mostly, I want to put in the fireblocking and build the soffit underneath of it.

**thekctermite** · 01-08-2010, 03:10 PM

You don't have to isolate the horizontal soffit from the horizontal floor joists at all. You only have to isolate the vertical wall space from the horizontal soffit. Hope that makes sense!