Replies

1. 
   blue_eyed_devil | Jan 30, 2005 10:32pm | #1

   Dennis, I've framed chases for probably a couple hundred zero clearance fireplaces and I've never, ever, known anyone to drywall the interior. I've run into different requirements regarding the draftstopping issues. It seems that every locality has their own interpretations, but most simply require one draftstopping somewhere in the chase above the unit.

   I use osb to create the draftstopping. I like to create a seal so that the chase cant draw attic air if a fire should start in the chase somewhere. I easily accomplish this by drawing the outline of the chase on the floor, then cutting a piece of plywood to match. I then nail that piece of plywood onto the ceiling and use it to frame my vertical wall to it.

   Its a very simply solution on flat ceilings....somewhat more complicated on sloped ceilings.

   blue

   Just because you can, doesn't mean you should!

   Warning! Be cautious when taking any framing advice from me. There are some in here who think I'm a hackmeister...they might be right! Of course, they might be wrong too!

2. 
   Piffin | Jan 30, 2005 10:43pm | #2

   The thing that is required is firestopping/ or draftstopping so that if a fire should break ourt in the cahse, it will not spread to other portions of the house, such as between cieling and upper floor or into the attic or soffit. A continuous SR finish on the interior of the chase is only one wway to do this, possibly the best way, but not the only way to satisfy codes and reality

    

    

   Welcome to the
   Taunton University of Knowledge FHB Campus at Breaktime.
    where ...
   Excellence is its own reward!

1. 
   blue_eyed_devil | Jan 30, 2005 10:57pm | #3

   Piffin, you are using the two terms firestopping and draftstopping as if they are one term....which they are not. In a world where money and time is not a factor, you could argue that every wall should be a firestop, but in the real world its not needed. You could use all fireproof lumber, solid core doors, doors with fire closer installed, fire alarms, sensors built into every cavity, etc, etc, etc.

   The firebox specs are suggesting unneccessary CYA ideas that are confusing to amatuers. All our installations are inspected and approved by professional fire marshalls and/or building inspectors which follow local fire marshall guidelines.

   blueJust because you can, doesn't mean you should!

   Warning! Be cautious when taking any framing advice from me. There are some in here who think I'm a hackmeister...they might be right! Of course, they might be wrong too!

1. 
   Piffin | Jan 31, 2005 12:15am | #5

   I mixed terms with the slash mark specifically because some areas require one and some the other. He needs to know what his local codes guys will require. 

    

   Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

3. 
   gdavis62 | Jan 30, 2005 11:44pm | #4

   Where I build, the inspector requires the inside of zero-clearance fireplace chases to be rocked with 5/8 firecode gypboard, and joints sealed with aluminum firecode tape.

   Don't know why, exactly, but he OKs the units sitting on a wood-framed deck, but then wants the cavity interior, from that deck all the way to the roof, lined.

4. 
   djj | Jan 31, 2005 01:49am | #6

   Blue, Piffin, Gene,

   Thanks for your replies. Our local building code only requires 3/4" material at the top of the chase for draftstopping, which we will have. 

   Just to clarify, my real concern was more to do with energy efficiency. With one wall of the chase being an exterior wall with no sheetrock on it, the building envelope now has a big 4'x12' hole in it. Maybe this is not as big a deal as I am making it.

   Thanks again everyone!

   Regards,

   Dennis

5. 
   dIrishInMe | Jan 31, 2005 02:02am | #7

   >> I haven't called the inspectors yet but it seems they might not be happy with closing up a section of wall with sheetrock before the 4-way is done.  <<  What's a "4-way"?  I'm guessing plumb/elect/HVAC/framing inspection?
    

   Matt