Got my stove and chimney installed. Now I am wondering about the gap between the roof sheathing and the stove pipe. My wife seems to think that bugs will enter through the air gaps in the roof flange and then thru that gap. I was going to pack the gap with insulation. Would this work or is there a better method?
Question About Thru Roof Chimney
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What brand chimney? '"Stove pipe" doesn't go through roof sheathing.
Stove pipe is the connector pipe from stove to chimney or chimney support box. Connector pipe stops 2 inches below finished ceiling.
Do you have horizontal ceiling joists with attic, cathedral slopped ceiling or something else? Chimney kits are UL listed (tested) and must be installed to manufacturers installation instructions. They must be installed as tested.
Stove pipe is the connector pipe from stove to chimney or chimney support box. Connector pipe stops 2 inches below finished ceiling.
Do you have horizontal ceiling joists with attic, cathedral slopped ceiling or something else? Chimney kits are UL listed (tested) and must be installed to manufacturers installation instructions. They must be installed as tested.
Ok, sorry for the wrong verbage. I've got Selkirk insulated double wall stainless steel "chimney" going out thru the roof, which I guess can be considered a cathedral. I cut the hole thru the sheathing over size as instructed, so just wondering about that gap now.
ken morgan
New Member
My phone doesn't take pics, but I'll give it a whirl tomorrow. All it is is the gap between the chimney pipe and the roof sheathing I cut through when I installed the chimney.
No, 2 inches of airspace. That's why they make an insulation shield to keep insulation away from chimney pipe in attic installation.
Insects could only go under the storm collar and into the support box. Not an issue.
We've seen many installs with connector pipe only through windows, roofs, you name it, so take "stove pipe" literally as if you had only single wall pipe all the way. Don't laugh, it's been done.
Insects could only go under the storm collar and into the support box. Not an issue.
We've seen many installs with connector pipe only through windows, roofs, you name it, so take "stove pipe" literally as if you had only single wall pipe all the way. Don't laugh, it's been done.
ken morgan
New Member
did you have something that looks like this? If it is installed properly under the shingles or roofing then you should not have any issues, but I am far from being a pro at this.
ken morgan
New Member
No, 2 inches of airspace. That's why they make an insulation shield to keep insulation away from chimney pipe in attic installation.
Insects could only go under the storm collar and into the support box. Not an issue.
We've seen many installs with connector pipe only through windows, roofs, you name it, so take "stove pipe" literally as if you had only single wall pipe all the way. Don't laugh, it's been done.
yeah one of my neighbors has a getup that does not make much sense to me, a 6" double wall pipe that goes up about 12' , then horizontally about 10' through a fireproof thimble and the wall then another 14' straight up...all of it uninsulated. he has to run his stove at max burn to keep it drafting.....I am afraid to stay their for fear of CO poisoning when the fire gets low.....but he is Canadian and refuses to listen to a word I say. at first I thought it was double wall insulated but he said nope....I just go uhmm.....OK.... and stopped worrying about it last year.
Yes, this is installed. The one I have is made by Selkirk that has verticle slits around the top that would be hidden by the storm collar but not sealed. This is where I thought the insects could enter.
Coaly, I am wonder then if I am missing the insulation shield. I described what I was going to do to my local hardware store who sell a lot of this stuff in my area and they basically showed me what I needed.
Insulation shield isn't used with Cathedral box.
Here is a page that shows the different installations;
(broken link removed to http://www.selkirkcorp.com/~/media/selkirk/reference-documents/common/file/product-literature/chimney/sure-temp/sure-temp-installation-guide.pdf)
Selkirk calls a Cathedral Kit, "Pitched Ceiling Kit". The box is very deep so when it is level, the bottom of the box toward peak extends down at least 2 inches below ceiling. The steeper the pitch, the deeper the box that is needed. The flashing on the roof above it closes in the support box.
The insulation shield for between ceiling joists in an attic is simply a big piece of sheet metal curled around the pipe to prevent insulation from getting near the chimney. It is capped by a piece of sheet metal like a huge storm collar to prevent anything from falling in around the chimney pipe. The few cathedral ceiling support boxes I've removed have only had a few small moths in them after 20 years or more. So insects don't seem to go under the storm collar and make the sharp turn downward and down the pipe.
Here is a page that shows the different installations;
(broken link removed to http://www.selkirkcorp.com/~/media/selkirk/reference-documents/common/file/product-literature/chimney/sure-temp/sure-temp-installation-guide.pdf)
Selkirk calls a Cathedral Kit, "Pitched Ceiling Kit". The box is very deep so when it is level, the bottom of the box toward peak extends down at least 2 inches below ceiling. The steeper the pitch, the deeper the box that is needed. The flashing on the roof above it closes in the support box.
The insulation shield for between ceiling joists in an attic is simply a big piece of sheet metal curled around the pipe to prevent insulation from getting near the chimney. It is capped by a piece of sheet metal like a huge storm collar to prevent anything from falling in around the chimney pipe. The few cathedral ceiling support boxes I've removed have only had a few small moths in them after 20 years or more. So insects don't seem to go under the storm collar and make the sharp turn downward and down the pipe.
Try as I might, I can't for the life of me get a picture uploaded. Upload tab doesn't work in here, and photo bucket just sends me in circles. 
Okay, I was just reading an article on "air tight" stoves here on the forums and was wondering about it.
When hard wood is not available, what is the tao for feeding the older Fishers over night? The wood here on my land appears to burn too hot to bank up. The chimney temp was way up over 500° which kind of alarmed me.
When hard wood is not available, what is the tao for feeding the older Fishers over night? The wood here on my land appears to burn too hot to bank up. The chimney temp was way up over 500° which kind of alarmed me.
What model Fisher? Factory Baffle in Fireplace Series?
Your wood probably out gassed quickly (lots of flame) and needs to be turned down.
Are you using single wall connector pipe with magnetic thermometer?
Was thermometer low on the pipe sensing heat from the stove as well?
Try your temp reading near the chimney support box where it dumps into chimney. If single wall pipe, the surface temp is about 1/2 the inner flue gas temperature. The object is to keep above 250* f to the top of chimney when smoke is present. More than that is waste and less than that allows water vapor to condense allowing smoke particles to stick forming creosote.
Your wood probably out gassed quickly (lots of flame) and needs to be turned down.
Are you using single wall connector pipe with magnetic thermometer?
Was thermometer low on the pipe sensing heat from the stove as well?
Try your temp reading near the chimney support box where it dumps into chimney. If single wall pipe, the surface temp is about 1/2 the inner flue gas temperature. The object is to keep above 250* f to the top of chimney when smoke is present. More than that is waste and less than that allows water vapor to condense allowing smoke particles to stick forming creosote.
Thermometer was about two thirds up single wall pipe. Dampers were closed a bit and the in pipe damper was closed about half way.
What do you mean "baffle it"? Normally I don't talk to stoves, but I know I could confuse it good if necessary .
What do you mean "baffle it"? Normally I don't talk to stoves, but I know I could confuse it good if necessary .
ken morgan
New Member
Do a search in Coaly's posts for baffle. he explains how to make a baffle for the early Fishers that did not have baffles. this will make your stove work so much better its literally like a different stove.
It is more critical than "closed a bit".
When starting spin them open a few turns. This is the only time they will be open more than 1 turn each.
Close down to 1 turn open as fire gets going. Close more as necessary to slow fire.
With your older style door seals (should be round rod) you should be able to run closed more than tighter sealing doors.
Probably close all the way, and crack open 1/8 to 1/4 turn overnight? No one can tell you exactly where to set it. Every stove is different since the chimney controls the stove. Weather conditions (temperature and atmospheric air pressure) and fuel also change your settings for heat output.
Most stoves operate fine overnight at 1/2 to 1 full turn when maximum heat is needed, but yours may leak and fuel go crazy with that much air, so you may need to run half that air.
The baffle will stabilize your stack temps making it much more comfortable to use without temperature spikes.
This thread was written for the single door stoves that never had a factory baffle. Your model had a smaller factory baffle added in 1980. My baffle was based on the same design but now with more efficient chimneys it can be fine tuned for each chimney. They could only design them for the poorest drafting, oversize chimney when new, not knowing what each stove was being connected to. So adjust for your chimney size.
(your plate cost is going to be more since your stove is double wide) USE 5/16 thick steel plate. NOT 1/4 inch.
https://www.hearth.com/talk/threads...d-fisher-more-heat-less-smoke-under-25.74710/
When starting spin them open a few turns. This is the only time they will be open more than 1 turn each.
Close down to 1 turn open as fire gets going. Close more as necessary to slow fire.
With your older style door seals (should be round rod) you should be able to run closed more than tighter sealing doors.
Probably close all the way, and crack open 1/8 to 1/4 turn overnight? No one can tell you exactly where to set it. Every stove is different since the chimney controls the stove. Weather conditions (temperature and atmospheric air pressure) and fuel also change your settings for heat output.
Most stoves operate fine overnight at 1/2 to 1 full turn when maximum heat is needed, but yours may leak and fuel go crazy with that much air, so you may need to run half that air.
The baffle will stabilize your stack temps making it much more comfortable to use without temperature spikes.
This thread was written for the single door stoves that never had a factory baffle. Your model had a smaller factory baffle added in 1980. My baffle was based on the same design but now with more efficient chimneys it can be fine tuned for each chimney. They could only design them for the poorest drafting, oversize chimney when new, not knowing what each stove was being connected to. So adjust for your chimney size.
(your plate cost is going to be more since your stove is double wide) USE 5/16 thick steel plate. NOT 1/4 inch.
https://www.hearth.com/talk/threads...d-fisher-more-heat-less-smoke-under-25.74710/
Wow, there was a lot of info on that page!
I didn't realize the dampers were adjusted that minutely.
I noticed a gap in the center of the double doors at the top where the doors come together perhaps a quarter inch wide. When the doors are closed you can see fire within. Is this normal?
Its going to be a bit before I can get the baffle made. In the mean time, how much would you recommend closing the chimney damper for an over night burn as a starting point?
I didn't realize the dampers were adjusted that minutely.
I noticed a gap in the center of the double doors at the top where the doors come together perhaps a quarter inch wide. When the doors are closed you can see fire within. Is this normal?
Its going to be a bit before I can get the baffle made. In the mean time, how much would you recommend closing the chimney damper for an over night burn as a starting point?
Your door seal style will have a small leak usually at top and bottom of doors where they meet. So yours is far less "air tight" than newer style that was used until the end of production.
Wide open is your starting point.
The colder it gets outside and the hotter it is inside the flue is your differential temperature. That is what makes the draft stronger, the more difference in temperature inside and out. Now with mild weather you may need damper open or closed just very slightly. As it gets colder and draft increases you will find you can close it more slowing draft.
Try with the fire stabilized, closing air dampers down to 1/4 turn and see how hard it burns. If it burns harder than a lazy burn, I'd close the flue damper a bit until you notice the fire slow down. This setting may be completely different on a cold 10* day.
Time will tell if you're running closed too much forming creosote. It's better to err on the side of leaving too much heat up keeping a clean stack than to slow it too much forming creosote when you don't know how fast you create it. It can form rapidly when burning too cool, so check frequently until you have a good idea how much forms. You should be able to get down to cleaning once in the middle of season and once at season end.
Wide open is your starting point.
The colder it gets outside and the hotter it is inside the flue is your differential temperature. That is what makes the draft stronger, the more difference in temperature inside and out. Now with mild weather you may need damper open or closed just very slightly. As it gets colder and draft increases you will find you can close it more slowing draft.
Try with the fire stabilized, closing air dampers down to 1/4 turn and see how hard it burns. If it burns harder than a lazy burn, I'd close the flue damper a bit until you notice the fire slow down. This setting may be completely different on a cold 10* day.
Time will tell if you're running closed too much forming creosote. It's better to err on the side of leaving too much heat up keeping a clean stack than to slow it too much forming creosote when you don't know how fast you create it. It can form rapidly when burning too cool, so check frequently until you have a good idea how much forms. You should be able to get down to cleaning once in the middle of season and once at season end.
It was cold this morning so I experimented with damper settings and the like, recording the temp on the upper stove pipe above the pipe damper, stove pipe below damper, and the stove itself. Results gave me some valuable insight on how it all worked and it really warmed the cabin up nice!
ken morgan
New Member
and thats what it boils down to. each stove and chimney setup is different, so only experimenting and recoding data will tell you what works best for yours. have fun!
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