Stove Clearance

  • 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.

Watkins

New Member
Sep 3, 2022
1
North America
I need some advise on placing a wood stove against a noncombustible wall. The wood stove is a Forester Pedestal US2000E-P and the clearance requirements are 15" on the rear of the stove on a combustible wall. I couldn't find anything online and when I called the company, it sounded like they didn't want to give me a number, probably because of liability. From reading, it sounds like the clearance is reduced once you start adding noncombustible barrier. It's not going to be the end of the world if I leave the clearance at 15". I just want everything to be safe and to pass inspection. I bought triple walled pipe, ceiling and roof kit, so everything above the stove should be good. The pipe will be going straight up through the ceiling and roof and 2' passed the ridge line.

Another question that I have is on the noncombustible wall and leaving a 1" air gap. Growing up, we've always had a wood stove that just had stone or tile on the wall as the heat barrier and this is how I've thought was the proper and safe way of doing it. I've already took off the sheet rock and was planning on putting Durarock on the wall with either tile or a stove veneer. After doing more research, it seems like the proper way to do it is to leave a 1" air gap between the wall and the cement board. From my understanding of this is because there is a noncombustible layer, there are combustible wood studs, insulation, and exterior plywood within that 15" clearance? I've seen lots of videos and pictures or people not leaving this 1" gap. Where I have seen it is when they use a metal heat shield over a sheet rock or T&G pine boards. Do I still need to have this 1" air gap if I use cement board with stone veneer and how much clearance behind the stove do you think I should have with either situation?

I would like to know for sure on where I stand on this clearance so I can start making the path through the ceiling and roof.


 

begreen

Mooderator
Staff member
Nov 18, 2005
96,475
South Puget Sound, WA
Putting a non-combustible surface on a wood stud wall is not "non-combustible". The cement board and tile will conduct heat to the studs. Therefore, in this scenario, the combustible distance is to the wood studs. A non-combustible wall would be 8" of brick or masonry or one constructed entirely out of non-combustible materials. This could be done with metal studs, then cement board and tile.

The cement board wall with a 1" gap behind it and open at the top and at least 1" at the bottom is a wall shield which is defined in NFPA211. This can be used for a clearance reduction down to 12" if the stove is unlisted or if permitted in the stove's documentation. In this case, the clearance is still measured to the wood studs behind the ventilated heat shield.

In this case, the manual has no provision for a clearance reduction so it is better to stick to the 15" requirement unless the local inspecting authority will accept a reduction to 12" using a proper NFPA 211 wall shield.