Wall above fireplace gets black soot. How to prevent?

[Don2222]

Hi
A friend has a fireplace (Maybe a heatilator type) with metal blocking plate and nice round easy to open flue damper gets black soot on the walls!

There is also a Harman P61a pellet stove in the next room blowing the heat around but it has an OAK and not much black on the walls above that.

These are cathedral ceilings and the black is close to the ceiling but on the walls and some black on the ceiling.
What is the vent in the wall above the fireplace for? There is one on the other side too?
What can cause that? Any suggestions what to do?
See pics

 

[DAKSY]

The sooting immediately above the fireplace opening is a sign of poor drafting of the wood fire. Could be trees or another building or some feature of THIS building causing the wind to affect the draft. Maybe the chimney pipe is too short. Do you have pix of the outside?

 

[webby3650]

It's a really strange soot pattern though. Something strange is going on here.

Does he see smoke actually exiting the fireplace? See smoke, smell smoke?

 

[webby3650]

If those vents are back to back, then the idea was to pull heat from one room to the other. That won't do any good at all. It will likely have adverse affects on an open fireplace. It could be pulling smoke out of the fireplace and transferring it throughout the house.

 

[jetsam]

It's a really strange soot pattern though. Something strange is going on here.

Does he see smoke actually exiting the fireplace? See smoke, smell smoke?

Too strange to be airflow, maybe.

You may be seeing the results of someone cleaning the wall with a swiffer-type spongestick.

 

[mcdougy]

My guess....its dirt,dust not soot. Caused by heat transfer through drywall. A thicker coat of latex paint may stop the flow. Check out "stud ghosting"....often in a garage. No vapour barrier is causing the affect.

 

[webby3650]

Too strange to be airflow, maybe.

You may be seeing the results of someone cleaning the wall with a swiffer-type spongestick.

No, typically it's referred to as ghosting. Where the studs, joists, and rafters are all highlighted with a black or dark streak. It's uncommon to be directly around a fireplace, except a vent free gas fireplace. It will happen On a ceiling where the attic insulation is insufficient. Not so much on the walls though. Directly above the fireplace would make sense, but not all over like that..

 

[webby3650]

My guess....its dirt,dust not soot. Caused by heat transfer through drywall. A thicker coat of latex paint may stop the flow. Check out "stud ghosting"....often in a garage. No vapour barrier is causing the affect.

If the the room behind the fireplace was unconditioned I would agree, not if it's conditioned living space though.

 

[mcdougy]

If the the room behind the fireplace was unconditioned I would agree, not if it's conditioned living space though.

With the fireplace stack in the wall cavity like that, is what has me wondering? Dirt being collected on the studs due to mass heat in entire cavity that is slowed at the studs.?

 

[webby3650]

If so, it's extremely uncommon.

 

[mcdougy]

To the op, have your friend monitor the wall temperature. I'm thinking there is a large amount heat being trapped in the wall cavity?

 

[webby3650]

Is there any chance there is a lot of candles/potpourri being burned in the house?

 

[mcdougy]

If so, it's extremely uncommon.

Are fireplace such as this common on an interior wall?

 

[webby3650]

To the op, have your friend monitor the wall temperature. I'm thinking there is a large amount heat being trapped in the wall cavity?

Could be, if so, something is wrong with construction of the fireplace.

 

[webby3650]

Are fireplace such as this common on an interior wall?

Absolutely

 

[mcdougy]

Absolutely

Check out the stone above the firebox in the last pick I believe.....something not right here

 

[webby3650]

Has the flue been inspected? It's possible the that there is a big problem with the chimney, like it's disconnected inside the wall.

 

[jetsam]

No, typically it's referred to as ghosting. Where the studs, joists, and rafters are all highlighted with a black or dark streak. It's uncommon to be directly around a fireplace, except a vent free gas fireplace. It will happen On a ceiling where the attic insulation is insufficient. Not so much on the walls though. Directly above the fireplace would make sense, but not all over like that..

Mmm, look at the ceiling and see if you still think so? Unless he has 12" on center rafters, maybe.

 

[jetsam]

Check out the stone above the firebox in the last pick I believe.....something not right here

I think the wood mantel is visibly discoloured there too, right below the ceramic cats.

Joke about ceramic cats being too hot to put on a wood mantel?

No?

 

[Don2222]

Too strange to be airflow, maybe.

You may be seeing the results of someone cleaning the wall with a swiffer-type spongestick.

Definitely soot in the air, because it killed this fan that was on top the pellet stove!
See soot on fan blade pics

 

[webby3650]

How does the pellet stove vent? I'm guessing that fan has something to do with this entire situation.

 

[Don2222]

How does the pellet stove vent? I'm guessing that fan has something to do with this entire situation.

pellet stove goes up 1 foot and out. Also has an OAK so no smoke will come out of the air inlet pipe if there is any back draft!

 

[webby3650]

pellet stove goes up 1 foot and out. Also has an OAK so no smoke will come out of the air inlet pipe if there is any back draft!

Yes, but that fan can certainly pull smoke and soot out of the system and distribute it throughout the house. Same goes with the fireplace. Disturbing the air can and often will disturb draft as well.

 

[webby3650]

Why not get rid of the pellet stove, put a real stove either in front of that fireplace or an insert. Get some real heat going in that place!

 

[bholler]

Is there a furnace either oil or gas heating the house also? That looks allot more like oil or gas soot than wood soot.

And webby that certainly looks like a zero clearance fireplace which means in most cases an insert is out.