Wall 1" air space venting?

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.

Mike50

New Member
Feb 22, 2018
9
Ks
I'm new to wood stoves. I recently bought a Woodstock soapstone keystone (used) Wood stove. I'll be installing in a corner. On walls I'll have the 1" air space, 1/2" cement board, and stone. I plan on having a mantle as well. Hearth will be built up 6" with 1/2" cement board and tile on top. My question is how do you vent the 1" air space with mantle being on top and the hearth on bottom? Is there a need for it to vent or can it be completely sealed? Thanks -mike
 
Hi Mike. Yes the wall shield needs to be open top and bottom in order for air to freely convect behind it. Normally folks just start the wall shield an inch above the hearth. Under the mantel you could make slots to exhaust the warmed air or you could cut slots on the top of the mantel to make them less visible.
 
Thanks for the reply. Since I'm going to be building the hearth up 6", does it need to be vented as well?
 
Thanks for the reply. Since I'm going to be building the hearth up 6", does it need to be vented as well?
the hearth floor does not need to be vented since your using cement board to build your thickness the tile on top, you exceed the required k-factor from wood stock, don't forget to design the hearth to have an extra 16" in front of the loading door to catch embers should any spill out.
One question, are your clearences that close to a combustible wall to have the extra shielding or is this just for extra protection?
 
the hearth floor does not need to be vented since your using cement board to build your thickness the tile on top, you exceed the required k-factor from wood stock, don't forget to design the hearth to have an extra 16" in front of the loading door to catch embers should any spill out.
One question, are your clearences that close to a combustible wall to have the extra shielding or is this just for extra protection?

I'm using the minimum clearance of 12" in a corner installation. If I'm reading Woodstock's manual correctly I also need the rear heat shield installed to go 12".
 
Picture of where it will be located,
 

Attachments

  • 20180210_100442.jpg
    20180210_100442.jpg
    60.5 KB · Views: 219
  • 20180210_100338.jpg
    20180210_100338.jpg
    99.9 KB · Views: 207
I'm using the minimum clearance of 12" in a corner installation. If I'm reading Woodstock's manual correctly I also need the rear heat shield installed to go 12".
Yes your right, be advised that the 12" clearance with rear heat shield and wall shields also factors in using double wall black pipe, if you chose to install single wall pipe the closest you can get the stove corners is 20" , pipe will be 18" to wall, and that with top vent. Single wall pipe requires a minimum of 18" to combustible, with a full wall shield from 1" above the floor to 1" below the ceiling you can reduce the clearance of the pipe by 1/3. But in all honesty as a home owner I wouldn't be to comfortable with that, when you can spend a few extra bucks and have a more durable stainless double wall black pipe that's rated to be installed 6" maximum to any combustibles
here's the manual for anyone following http://www.woodstove.com/images/editorial_support/KP PDFs/Installation-KP 2013 email.pdf
 
Thanks for the reply. Since I'm going to be building the hearth up 6", does it need to be vented as well?
No, the hearth is independent of the wall shield and needs to be made to meet or exceed the stove's requirement.
 
Yes, I will be using double wall black pipe. A question on that, I'm reducing down from 7"-6" out of the stove. Is there a double wall reducer I need to use or will a normal single wall reducer work on double wall pipe?
 
Yes, I will be using double wall black pipe. A question on that, I'm reducing down from 7"-6" out of the stove. Is there a double wall reducer I need to use or will a normal single wall reducer work on double wall pipe?
Woodstock recommends going no smaller than 7" for the Keystone.
Another question about the pipe, can I use 2 telescoping sections on top of each other?
I suppose, but why?
 
Yes, I will be using double wall black pipe. A question on that, I'm reducing down from 7"-6" out of the stove. Is there a double wall reducer I need to use or will a normal single wall reducer work on double wall pipe?
Your going to have to look for a 7" to 6" stainless steel appliance adapter to mate the 7" stove collar to 6" double wall, it would be nicer if you went with solid double wall pipe until you had enough room to install (1) telescoping double wall pipe, it will look much sleeker. I was able to do that with my setup, I used one 3ft length of double wall then bought the 60" telescoping pipe
 
Woodstock now says it can be reduced down to 6". Im Having trouble figuring out pipe lengths. My ceiling joist ends up being in the center of where my stove is. Being roof trusses I cannot cut a frame in so im moving it back about 14" to be centered in between ceiling joists. I figure i will need 2 45 degree elbows with a 12" peice in between and then have about 2'5" left down to stove. Getting the pipe from Menard's and they only have 2' sections and 12-18" adjustable. I'm assuming double wall cannot be cut. Any suggestions would be appreciated
 
If you go with a stainless 7 to 6" reducer the wall shield must extend above the top of the reducer. It's also important to pay attention to how close will this reducer be to the mantel.
I figure i will need 2 45 degree elbows with a 12" peice in between and then have about 2'5" left down to stove.
What about a 12" length of 6" selkirk dsp + the 12-18" telescoping section?
 
That's what I was thinking but I didnt see any 12" lengths at Menard's and didn't see it in the supervent pipe manual.
 
Yes, it's not the most intuitive webpage. Use the drop down variation menu, it shows the various length options.

Screen Shot 2018-02-23 at 8.43.06 PM.png
 
Does the stove have to be a corner install? Why not line it up on the straight back wall build a larger hearth for wood storage and skip the elbow's on the dvl? Don't get me wrong, I like corner installs, but the room has to be large for it to work, corner's take up a lot of space and a straight up and down chimney is way better than any chimney that has bends in it.
 
Piggy-backing off of kennyp's comment, make sure side loading will be comfortable, and not tight or awkward, especially with a wall shield in place (it appears that the keystone has a right side door).
Also, hearth pad for corner install would be offset and stick out into doorway (potential toe cracker ?).
 
Piggy-backing off of kennyp's comment, make sure side loading will be comfortable, and not tight or awkward, especially with a wall shield in place (it appears that the keystone has a right side door).
Also, hearth pad for corner install would be offset and stick out into doorway (potential toe cracker ?).
Yea I've considered moving to the rear wall but I really like the corner installs. As far as the hearth sticking out, it will be at a 22.5* off the doorway (parallel with the side of the stove) if that makes sense. The way the stove is angled it works out perfect missing the cased opening to the side load. I appreciate all the help so far from everyone though. Glad I found this site!