Chimney firewall

glenn60 · 11-15-2005, 01:20 PM

:confused: I am wondering if I need to install a firewall (chimney chase) around the top of my chimney in my attic. My fireplace is in my living room adjoining my garage. The chimney chase runs up the wall (inside my garage) into the attic. The portion of the chimney in my attic has a short wall around it but is not fully enclosed. I can look over the top of the wall down to the bottom of the chimney chase. I am wondering if I should fully enclose the chimney chase in the attic up to the roof to create a firewall and prevent stacking or should it be open to allow excessive heat and any leaking fumes to escape?

FireballBrick · 11-16-2005, 04:47 PM

Hi Glenn,
Sounds like you definitely have something that needs to be looked at, do you think you could post some pictures? Chimneys and fireplaces are one of those things that have to be done right, and not just for aesthetics, you know? Post some pics and I will try to get back with you.
Adrienne

glenn60 · 11-18-2005, 07:08 PM

I attached a couple of pictures of my chimney and the chase. As you can see it's open to the attic. One thing I forgot about is there are two 4 inch ducts running up either side of the chase. They aren't connected to anything so I'm not sure what they're for. You can also see two HVAC ducts running up the chase into my living room.

K2eoj · 11-18-2005, 10:37 PM

My area requires a 1 hr firewall between the garage and living space. From what I'm seeing in the pics, the ceiling of the garage should be firerocked and it looks looks the common wall to the house already is. Having the FP stack open above ceiling line would be ok in my code book. Another way to make the 1 hr seperation would be to continue the common wall rock up the trusses to the roof sheathing. Then you would have to rock the chase around the pipe because there is a fire path back to the living space.. Either way in my book it is more important to keep your flamable garage seperated from the living space. Open stacks above ceiling line are ok here.

FireballBrick · 11-21-2005, 11:44 PM

Thanks for posting the pics Glenn, it was very easy to see what your question was about with the pics included. Hammer says that it meets code, and I don't necessarily disagree with that comment. However, I know that if it was my house, I would want something wrapping that just so I could sleep better at night. My suggestion is to get a couple of sheets of thin Durock and cut them to fit each side on the outside of the framing. Screw those into place, and voila, you are done. I recommend buying a diamond blade for your circular saw and cutting the Durock that way, although some people score and snap it. DO THIS OUTSIDE!!!! You might spend 25 bucks for a little peace of mind. It shouldn't require more than that to get this done.
There should be no leaking fumes, and metal stacks like yours are usually double walled, so I do not see heat being a big issue.
Hope this helps,
Adrienne
Fireball Construction