Need Help: New Chimney & Hearth Install

[MacinJosh]

Hey guys,

Finally getting around to installing a new class A chimney and hearth pad and I'm looking for advice and tips from the pros. My initial thought was to begin with the hearth pad. My wife and I have picked out some porcelain tile and I made a cardboard template. I was going to take out the laminate flooring and tile straight to the concrete underneath. Ideally, I wanted the hearth pad to end at the edge of the one wall and not stick out past it as I don't think aesthetically that looks as good. Planning on going with a BK King so I read the manual and measured clearances and sketched where the stove would sit. Then I realized I have a problem.

The house has an existing chimney and chimney pipe (behind a chase in upstairs bedroom) but the old stove pipe and stove were removed. It appears to me that the owner then boarded up the ceiling (see newer colored wood in floor compared to old) and then installed ductwork directly underneath it (crap!) and then framed around that with the bulk head. So.......I cut a small hole in the ceiling so I could see what was up there. It looks to me like I'm going to have to install the ceiling support box where that hole is and build up from there. This means going straight up through the ceiling I will come out in the bedroom NEXT to the existing chase so an offset is needed. My question is, can you run 45's in triple wall? From the stove I would go straight up to ceiling support with stove pipe, then I would have to go up a short distance with triple wall, 45 over, run another small distance, and then 45 again back up into existing chase. This means I will have to cut out part of chase and reframe around the chimney. I plan on removing old pipe and chimney. My thought was to open entire side of the chase to access it all. Other question I have, where stove sits is not DIRECTLY under the ceiling support box hole. Should I move the stove such that it is a straight shot? This would mean moving the stove further away from the walls and in turn, means a larger hearth pad. Thoughts?

Always appreciate the help on here guys. Hopefully you can get an idea from the pics. Thanks!

 

[begreen]

The largest angle usable for an offset in chimney pipe is 30º. There are no 45º class A pipe elbows. I would use double-wall to simplify and reduce the overall diameter of the pipe by 2" from 12" to 10". Or maybe get a Princess instead for an 8" OD chimney pipe? Also, pay attention to clearances for the stove pipe coming up from the stove to the support box. The minimum for double-wall stove pipe is 6". The current location looks too close to the sheetrock on the side duct chase.

 

[MacinJosh]

Thanks. Is there a minimum distance required between 30's?

No worries moving the ceiling support box further away from the bulkhead. I just cut that hole to see what's up there. Mostly confirmed my suspicion the chimney is above the ductwork. So two 30's will be needed it sounds like.

 

[MacinJosh]

The minimum for double-wall stove pipe is 6". The current location looks too close to the sheetrock on the side duct chase.

Okay, just thinking off the top of my head, doesn't the support box basically make the clearance? That will have to attach to the two floor joists and then use 2 x 6's on the other sides to box it in on all four sides. The stove pipe twists and locks into that correct? So isn't your clearance from the center of the support box to its edges?? Sheetrock can touch the support box, correct?

I guess I'm not following you.

 

[MacinJosh]

Does anyone on here have a chimney with an offset using two 30 elbows? I think I'm going to have to use an offset in order to use the existing chase. Here is a crude photoshop picture of what in trying to accomplish. Stove will be a corner install downstairs and I plan on coming up through the flooring and then offset over back into the chase.

Anyone done this? Looking for some help and guidance. Thanks.



Existing junk chimney I plan to rip out. Roof pitch is 5/12. Just use the 2-3-10 rule?

 

[kennyp2339]

1ST thing I see is the padding of the ceiling, where ever you put the ceiling support box you will need to take into account that using dvl pipe, you will need a minimum 6" clearance from those padded out sections.
Is it possible to install a through the wall kit and run the class a chimney outside, use 30deg elbows to go around the soffit then straight up and use an adjustable chimney support kit for the roof?

 

[MacinJosh]

1ST thing I see is the padding of the ceiling, where ever you put the ceiling support box you will need to take into account that using dvl pipe, you will need a minimum 6" clearance from those padded out sections.
Is it possible to install a through the wall kit and run the class a chimney outside, use 30deg elbows to go around the soffit then straight up and use an adjustable chimney support kit for the roof?

The ceiling is just Sheetrock. I plan on putting the ceiling support box in between the floor joists and framing around it. I will then have to cut out a section of flooring and carpet above it to accommodate the pipe and then offset into that chase.

 

[MacinJosh]

So the other side of that square hole in the ceiling I have cut is the floor next to the chase where I photoshopped the circle in.

I imagine I can pull back as much carpet or padding as needed. The intent would then be to reframe the chimney in and box around it so the new chase would have a reverse "L" shape I guess.

 

[kennyp2339]

You still need to be 6" minimum for double wall pipe from sheet rock, it also looks like the pad out is made of 1x2 wood.

 

[kennyp2339]

Okay, just thinking off the top of my head, doesn't the support box basically make the clearance? That will have to attach to the two floor joists and then use 2 x 6's on the other sides to box it in on all four sides. The stove pipe twists and locks into that correct? So isn't your clearance from the center of the support box to its edges?? Sheetrock can touch the support box, correct?

Ok, so yes your on the right track but... the ceiling support box is made to be nailed in to a 2x6 framed box, only the upper portion of the box sets the clearance for the class A pipe (which is 2" from the outside diameter) so 8" class A is about 10.5" OD then add another 2" for clearance. The bottom of the support box does not help with clearance from combustibles, due to the fact that there could be boxed out area's (like what your experiencing) so 8" dvl pipe has about a 9" OD then you measure 6" from that outside edge to get your minimum clearance, its still better than single wall pipe which is 18" minimum.

 

[MacinJosh]

Ok, so yes your on the right track but... the ceiling support box is made to be nailed in to a 2x6 framed box, only the upper portion of the box sets the clearance for the class A pipe (which is 2" from the outside diameter) so 8" class A is about 10.5" OD then add another 2" for clearance. The bottom of the support box does not help with clearance from combustibles, due to the fact that there could be boxed out area's (like what your experiencing) so 8" dvl pipe has about a 9" OD then you measure 6" from that outside edge to get your minimum clearance, its still better than single wall pipe which is 18" minimum.

You're talking stove pipe at that point though right? I plan on using double wall for my stove pipe anyway. Need to check with pipe manufacturer but I thought that was only like 2" from combustibles. Sounds like you are suggesting it's 6".

 

[Squisher]

It is 6". The 2"s you're thinking of is for double wall classA chimney. Double wall connecting pipe will be 6"s, and single wall is 18"s as Kennyp2939 said.

 

[kennyp2339]

Stove pipe from your wood stove collar to ceiling support box double wall black pipe aka dvl is 6" minimum clearance OD, class a double wall insulated (the shinny pipe) is 2" clearance from OD.

 

[MacinJosh]

Are you referring to the white clearance? Distance between stove pipe and bulkhead?

 

[Squisher]

Also where you mention coming through and 30ing over to the chase. That will all hav to be covered with a chase. It can't be exposed to the living area at all once it goes through the ceiling support box.

 

[kennyp2339]

Are you referring to the white clearance? Distance between stove pipe and bulkhead?

View attachment 194347

YES

 

[Squisher]

Are you referring to the white clearance? Distance between stove pipe and bulkhead?

View attachment 194347

Yes.

 

[Squisher]

I'll butt out so Kennyp2339 and I aren't double posting. He has you well looked after.

 

[kennyp2339]

You can go through the wall outside and do something like this?

 

[kennyp2339]

I'll butt out so Kennyp2339 and I aren't double posting. He has you well looked after.

Lol the more the merrier, I would rather have Bhollar and BG explaining this.

 

[Squisher]

Ha, you and me both. Lol. Luckily for a relative noob like myself they around to help and correct if I get to far into the deep end.

 

[MacinJosh]

Also where you mention coming through and 30ing over to the chase. That will all hav to be covered with a chase. It can't be exposed to the living area at all once it goes through the ceiling support box.

Yes. That is my exact plan. It will be boxed and framed in with existing chase. Like an L shape.

 

[MacinJosh]

YES

Well crap! How do I get around that? :-(

 

[MacinJosh]

View attachment 194348
You can go through the wall outside and do something like this?

Unfortunately no. The other side of that wall is my garage, not outside.

 

[begreen]

Well crap! How do I get around that? :-(

Start with some accurate measurements. M&G's catalog has the dimensions for the ceiling support box and piping. Figure out how close the DVL will actually be to the two bulkheads. If you have no options then some options may be to relocate the stove in another area or another location in the room. Or, if the inspector will approve, to shield each of the bulkhead surfaces with an 18" section of metal on 1" non-combustible standoffs.