Help me understand hearth wall protection requirements

[williaty]

I'm still working through what all will need to be done beyond the stove and chimney. Our house is, effectively, an A-frame with a blunted top. Think old barn roof with the two different pitches but the roof goes all the way down the ground. The room the stove is going in is open top to bottom so it's a straight shot up for the chimney. Here's a picture of the room, taken from the 2nd floor loft. The stove will be over in the far corner near the sliding glass door. To maintain the require clearances to the A-frame, (which is pine and obviously combustible), the stove will have to be just to this side of the A-frame (rather than closer to the end wall, which is what I had hoped for). To maintain clearance at the top where it pokes out the nearly-flat portion of the roof, the stove will be set out away from the wall a bit at the bottom (since the side walls slope you end up with more clearance at the bottom than the top).

Now, here's the question: The stove will be much farther than the manufacturer's required clearances to the side wall at the bottom. However, they'll taper closer and closer as you rise up (though always respecting the clearance to the double wall pipe). Do I need to treat any portion of that will with some kind of non-combustible material, or is it safe to leave as-is (plywood over styrofoam insulation) because we'll be well outside the stove's clearances?

 

[begreen]

Should be fine without shielding as long as the stove and pipe clearances are honored or exceeded. It's good to hear you are going to use double-wall connector. That is a long run of pipe. You could use 45s to create an offset if the goal is to put the stove closer to the wall. If so I would add some additional support for peace of mind.

Is there already a chimney on the house? I'm trying to figure out if that box near the skylight is a chimney support box.

 

[Oldman47]

I get it. You have a mansard roof that extends to the ground. If BG is correct I would look at using a straight run of double wall pipe to that chimney support. It would put the stove in a very good spot for heat to rise to the upper level. The stove clearance will be specified right in the stove documentation. Once you leave the stove, the clearance to combustibles is governed by the stove pipe you are using. For the first few feet I would use the stove specs since most are designed to have the specified clearance until you reach about 84 inches from the floor.

 

[williaty]

Is there already a chimney on the house? I'm trying to figure out if that box near the skylight is a chimney support box.

There had been a woodburning stove in the house sometime prior to our ownership. The previous owner removed it, but the chimney penetration was never removed or sealed. When we bought the house, we did not anticipate ever having a wood stove, so we had the box removed and the penetration sealed when the new roof was put on. Two winters in the house now and we're finding heating is a real problem, so we're (seriously) exploring the use of a wood burning stove. The stove won't be positioned where the old one was. We want it down at the end just because of the way we use that room (there's built-in shelving now where the old stove was).