New zero clearance questions

[clark_bailey]

Ok, I got the wall knocked out, rough opening framed up in the chase, platform framed and covered and I have some questions. One, there is roll insulation on the wall behind the fireplace (inside studs), do I need to remove the insulation or put sheetrock over the insulation? do I need to put sheetrock and insulation on the side walls too (in between studs)? My chimney chase goes all the way to the roof, it is insulated seperating the attic space from the chase space (inside the studs is roll insulation), do I need to add sheetrock over the insulation all the way up, does this chase need a firestop (it is about 12 feet high to the roof). Firestop material if needed, sheetrock or plywood? I have read the install manual over and over but these points are not covered in depth. I am a lieutenant in the professional fire service and would like to have a safe install. I do not want to get a call to my own home due to a fouled up install. The fireplace is a kozyheat z42. I am going to use metalbestos (sellkirk) as my chimney pipe, it requires only 2 inches of clearance. The chase is 29 inches deep by 69 inches wide, I think I have the 2 inches covered! Any help is greatly appreciated. I am a do it yourselfer because I cannot afford to pay the local fireplace guy what they need for installation. Pics added today, hearth extension not yet started. I want to get the unit in and measure how high I can go so that the hearth cap stones do not interfere with the lower grill opening and closing for thermostat and fan service in the future.

 

[fishboat]

Clark,

There are much more knowledgable folks here than I, but I can share my recent install on a similar unit. The roll insulation in my wood framed chase was left as it is, however the installer made a number of galvanized strips about 1 inch by 17 inch tacked across the studs to hold the insulation in place. He used flashing material scraps. He did not drywall the studs/insulation. There is a firestop about 10 feet up from the floor (about 4-5 feet above the box). My chase is 21 inches deep by about 45 wide. I also have the packed chimney pipe up 21 feet inside the chase. The fireplace shop I got the unit from did the install ($400).

Do a search here on my name (fishboat) and you should find a post I made that has a picture of the my installed unit...no finish work done yet...you'll see how it's put in.

 

[clark_bailey]

Thanks fishboat, I will check out your pics and hopefully get a couple ideas. I still have a hard time believing that I am supposed to just sit the thing on a plywood deck. Seems crazy but that is what the instructions say you can do. Having a fire that close to the inside of the stud wall still makes me wonder a little about safety. Can I ask what chimney pipe you used?

 

[fishboat]

I don't have the paperwork handy, but it's Class A solid-pack pipe & I believe it came from Security Chimney (BIS burner mfg).

As you'll see in the picture, mine is sitting on 2 x 8 framing.

You'll probably want to put in a Z-strip cinder block piece of flashing just under your burner's box edge and into your hearth. This will keep any cinders that may fall between your box & the box-side of the hearth from contacting wood.

You can also search here on how to build the hearth...lots on info. I've done lots of work on figuring out what to do & how to do it. Let me know if you have questions...at least I can tell you where I'm at with a similar install.

 

[jtp10181]

If that's an outside wall of the house you want it sealed up as good as any other wall in the house. We drywall and then caulk the seams since it will be hidden. You also want a draft stop above, insulated like an attic. The rest of the chase can be fully insulated and that will help keep everything warm, but it is not required. Just remember that the fireplace must be installed INSIDE the envelope of the house and you don't want any breaks in that envelope. Fireplaces make bad windows if you know what I mean.

 

[DiscoInferno]

I think the main thing with the insulation from a safety standpoint is that there be no way for it to fall onto the fireplace. Drywall is probably overkill for that. My chase, unfortunately, is not insulated at all. Lucky it doesn't get real cold too much here. The outer shell of the Ultima is insulated, but not enough and not airtight.

Re: close clearance to combustibles: basically, the clearance/shielding/insulation is all built into the ZC box, so the outer shell never should get that hot, especially if you run a blower. My Ultima has a heat shield between the firebox and the floor, and it never gets hot under the shield.

 

[clark_bailey]

Ok, the wall is an interior wall, behind the fireplace is a bedroom with 9 foot ceilings and a attic above it, (the wall in the pic with insulation bat showning). Sounds like I need to just make sure the insulation will stay up and not fall along with building a fire wall (stop) that is insulated between the fireplace and the attic area. The attic area of the bedroom behind the fireplace is only seperated to the chimney chase area by bat insulation. Sounds confusing I know, but the fireplace room is open with cathedral ceiling. Here is a pic of the upper wall area. Maybe this helps. Gotcha on the tips, thanks for all the advise.

 

[21acrewoods]

Those are helpful pics. thanks