Heat loss?

[doug crann]

Last wood burner I was around was a fireplace with a brick/mortar chimney outside the house. Thinking about adding a wood stove to our future house with a simple stove pipe but I am concerned with potential heat loss when you run the pipe thru the ceiling, the unconditioned attic and out the roof. Can you insulate right up to a box similar to this one? Or is there still clearance needed around the box? Either way heat will escape out the top of the box, will it not? Heat loss is not my real concern, it is where the heat will be escaping to that concerns me. The barn style building we are living in right now gets gigantic ice damns on the roof if we get any snow that accumulates on the roof. Will be using a metal roof on the new house, just like we have now but the ice damns and the gigantic ice bergs hanging off the roof concern me a bit. Or am I just being paranoid?

 

[BurnIt13]

The heat gain from the stove will outweigh any heat loss. And I'd keep the pipe closer to the peak, as opposed to having it at the bottom of the slope of the roof. We usually see a few posts every year about someones chimney pipe getting destroyed because the snow slid down the roof and hit it dead on.

 

[doug crann]

Like I said, not real worried about the actual heat loss, just where it will be going.....and the potential for ice damns that it will create. The counties building inspector informed me of the issue of snapped pipes...and then mentioned using a diverter of sorts to prevent it form happening. Have seen them on several local roofs, they are similar to this, sorry for the terrible picture, it is all I could find. But it is a simple steel wedge that bolts to the roof, in front of the pipe. There is small home not to far form us that has PVC vents thru the roof, at the edge. Even with the monster storm we had in 08 he had no troubles....

 

[MDFisherman]

I would contact the manufacturer of your chimney system and ask them. If the box is rated to mount to combustible wood, then it should be find to put fiberglass insulation next to it.

 

[kuma.jason]

Of the 3 pipe brands I'm very familiar with (Selkirk, MetalFab, DuraTech), I've never seen one need additional clearance around the ceiling box. However, most of them have a different component for on top of the ceiling box, usually called attic insulation shield, that prevents insulation from getting inside the box. As mentioned above, it would be wise to check with the specific brand's instructions or manufacturer.

Jason

Edit: Just noticed that your location is eastern Washington. Anywhere near Spokane? There has been a snow wedge around North Idaho / Spokane called "Snow Terminator". Very heavy duty and powder coated. We used them for a while when we were still installing locally. A nice product but a bit pricey.

 

[webby3650]

Every Class A chimney that I have every seen makes their box to attach directly to combustible supports. It's a support box, unless it attaches to framing members it wouldn't be able to support anything.

The TLC line from Hart&Cooley has an insulation wrap that's approves to be used in the ceiling box, around the pipe. It's to prevent radiation on the rafters as well as prevent cold air infiltration and condensation.
http://www.hartandcooley.com/products/tlcsi/shielding-insulation-wrap