Stove Pipe Clearance to Non Combustibles

I am ready to cut a hole in my ceiling and start the installation of the heat shield that goes in and I think I have a joist in the area I want. I really don't want to cut the joist and box it out to get my location so I want to move the single wall pipe that comes from the stove to the ceiling mount back towards my wall on the inside of the joist.

My wall will have hardi board spaced about 1 1/4" away from the drywall with ceramic tile on that, if I put my ceiling box where I want it inside my joist it will give me approximately 6" from the pipe to the non combustible tile wall. Is this acceptable and safe ?

Keith, you mentioned single wall black pipe. i think national standards specify 18" for minimum clearance to combustibles. However you also mentioned going through the ceiling and your concern is the ceiling joist. Most manufacturers of stove pipe have some type of thimble for the pipe to pass through, and usually recommend at least double wall insulated pipe to be inserted through the thimble and allow the double wall pipe to be as close as 2". The kits I've seen have the black pipe terminating at the ceiling box, adapt a collar from it to the insulated pipe, and then run that through the ceiling joists. (If this makes any sense to you.)

joeq wrote:Keith, you mentioned single wall black pipe. i think national standards specify 18" for minimum clearance to combustibles. However you also mentioned going through the ceiling and your concern is the ceiling joist. Most manufacturers of stove pipe have some type of thimble for the pipe to pass through, and usually recommend at least double wall insulated pipe to be inserted through the thimble and allow the double wall pipe to be as close as 2". The kits I've seen have the black pipe terminating at the ceiling box, adapt a collar from it to the insulated pipe, and then run that through the ceiling joists. (If this makes any sense to you.)

Thanks Joeq,

Perfect sense, I have the through the ceiling kit (thimble, adaptor from single to double wall, trim ring etc.) just wondering if my single wall pipe from the stove to the ceiling box will be ok 6" from the new non combustible wall ?

OK Keith, I think i better understand what your concern is now.When I needed to reduce my recommended clearances to the back of my stove, NFPA states that if I build a non-combustible wall to their specs, (which yours sound similar), then I was able to reduce my clearance by 66%, or to a foot, compared to the recommended 36". The black pipe is allowed 18" from the wall, but if you built a non-comb. wall, 66% of 18 is 6", so in my twisted way of thinking, sounds OK to me.(I won't sign anything saying so...I'm afraid to say. Sorry)

How is the hardibacker mounted to the drywall???

kevin

Or what gives it the 1 1/4 space?

KLook wrote:How is the hardibacker mounted to the drywall???

kevin

Or what gives it the 1 1/4 space?

Aluminum spacers is what I would like to use between the hardi and drywall, leaving at least a 1" gap at the top and bottom.

Sound ok ?

That's what NFPA recommends, how mine is mounted, and my town inspector OKd it.

joeq wrote:That's what NFPA recommends, how mine is mounted, and my town inspector OKd it.

Great, have any pictures ?

I have an idea and picked up a couple items today to see if it will work for cleaning up the gaps but maybe a picture will show me more.

Keith, my backboard behind my stove is about 4' tall and 7' long, and comprises of 2 1/2 sheets of Dura-rock hardboard covered with veneered red brick and mortar. i mounted the hardboard off the sheetrock with a couple packages of ceramic 1" spacers from my local fireplace store. They're made specifically for what we need them for. I can get you some pictures, but don't have any of the spacers as of yet. this is the view from the front, as you can see. I still haven't trimmed the edges yet, so when my girls come back this weekend with a camera, Hopefully I can shoot a pic from a side view.

Much appreciated, the pic shows the 1" gap at the bottom and it is what I was looking for. I will post up my plan for that area in a few days if I get that far by then .

Yeah, sounds good. I have seen walls catch fire through"non combustibles" in brand new houses when codes weren't followed. Amazing amount of heat transfer in solid blocks even. You are talking about trimming out the 1 inch space, it is for air circulation so be careful to not block it all.

Kevin

You are talking about trimming out the 1 inch space, it is for air circulation so be careful to not block it all.

Kevin[/quote]

Absolutely.

Definitely keeping air flow and before committing to my idea I will post pics for others opinions.

Anyone ever use a radiant barrier on the drywall before doing the 1" air barrier non combustible wall. The radiant barrier is just a foil type roll that comes in different sizes and sold at Lowe's and is supposed to reflect heat.

If someone is looking for inexpensive ceramic spacers, tractor supply has them. Just use ceramic electric fence post insulators...they are about an inch long, have holes in them for driving screws or nails through, and you can get 25 of them for $6 dollars.

Just an idea...

I was going to suggest the same thing...Freetown Fred clued me into the fence post insulator trick.