Plugged chimney cap

  • 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.
Status
Not open for further replies.
M

MogollonMonster

New Member
Oct 13, 2009
16
Flagstaff Arizona
Been running my Oslo for two months now. This morning I got up to restart and had smoke escape from the side door. After playing around with it a bit I could tell it wasn't drafting well. Got out the ladder, got up on the roof, fought through the snow, and checked the chimney cap. The mesh was plugged. I cleaned it out which solved the draft problem.

For the first month I ran poorly seasoned oak and well seasoned aspen. I had to keep the air supply mostly open with the oak to keep the fire hot enough. I ran hot fires with the Aspen and had to closely monitor the air supply to keep from over-firing. After one month, I inspected the cap and inside the chimney. There was no noticeable build up at that time. For the second month I burned mainly pinon and aspen, both seasoned. Recently I got a load of shaggy juniper which seems dry enough. It's very easy to start a fire unlike the oak. I've been running the stove with the air supply partially closed down with the juniper. The stove temps range between 450 and 550 and I get really good secondaries. Better than any of the other wood I've tried.

Couple of questions.

1) Could the shaggy bark on the juniper cause the plugged cap?
2) If you run a hot fire will it help keep the cap clean and if so how hot?
3) Any thoughts on removing the mesh?

Any other suggestions are appreciated. I'd like to minimize my number of winter trips on the roof.

Thanks, Jeff
 
Some people find removing some or all the mesh helps while others just remove the whole cap til the burning season is done. Dry wood is key, my cap doesn't have a spec of creosote and I'm burning 3 year old Locust.
 
In the past I also had some similar problems. I have a very large fireplace and tend to not burn hot enough. Towards the end of my burning seasons I started having the same issue. I have a very tall and steep roof 14/12 pitch. The chimney sticks up over 7 ft above the roof surface. So it is very difficult not to mention dangerous to go up there in the winter. I probably shouldn't be telling this here to some of you folks but I started using a .22 cal. rifle with bird shot to knock the screen clean. No neighbors no chance of hitting anything else. One shot per side and all was well till the end of the season. I have basically no creosote in the clay fluepipe just on the cap screen. So last fall I took some tin snips and enlarged a hole on each of the four sides. This has worked well for me. OK flame me
Brad
 
  • Like
Reactions: Jazzberry
Cutter said:
In the past I also had some similar problems. I have a very large fireplace and tend to not burn hot enough. Towards the end of my burning seasons I started having the same issue. I have a very tall and steep roof 14/12 pitch. The chimney sticks up over 7 ft above the roof surface. So it is very difficult not to mention dangerous to go up there in the winter. I probably shouldn't be telling this here to some of you folks but I started using a .22 cal. rifle with bird shot to knock the screen clean. No neighbors no chance of hitting anything else. One shot per side and all was well till the end of the season. I have basically no creosote in the clay fluepipe just on the cap screen. So last fall I took some tin snips and enlarged a hole on each of the four sides. This has worked well for me. OK flame me
Brad
Click to expand...

GASP!!! :ahhh:
 
Another forum member used a pellet gun a couple of seasons ago. Ya do what ya gotta do.
 
I'll give you a high five for the 22 idea. On a masonry chimney the teensy tinsy bird shot won't hurt anything and if the pattern was tight enough to do the job then that's a great idea. Further, the 22 shot is almost like sand. I wouldn't even worry about that shot landing on parked cars in the distance as it wouldn't do anything.

I removed the screen. They plug up even when you are doing your best with ideal firewood. It's not a reflection on your burning style or wood. Of course you need to consider the risk of removing the "spark arrestor" funtion of the cap but I don't think this is an issue with modern stoves. It's not like you're burning cardboard in an open fireplace. Worry more about the birds that are more likely to come down the pipe in the summer.

You can remove the screen from most caps and replace the cap to prevent rain from pouring down the flue.
 
Carbon_Liberator said:
Cutter said:
In the past I also had some similar problems. I have a very large fireplace and tend to not burn hot enough. Towards the end of my burning seasons I started having the same issue. I have a very tall and steep roof 14/12 pitch. The chimney sticks up over 7 ft above the roof surface. So it is very difficult not to mention dangerous to go up there in the winter. I probably shouldn't be telling this here to some of you folks but I started using a .22 cal. rifle with bird shot to knock the screen clean. No neighbors no chance of hitting anything else. One shot per side and all was well till the end of the season. I have basically no creosote in the clay fluepipe just on the cap screen. So last fall I took some tin snips and enlarged a hole on each of the four sides. This has worked well for me. OK flame me
Brad
Click to expand...

GASP!!! :ahhh:
Click to expand...
Those .22 cal bird shot shells are so ineffective, you are unlikely to kill a squirrel with one at 20 feet. Good for shooting mice inside the cabin.
 
I only have a 12-gauge and I am sure the neighbors wouldn't appreciate it. I'll think about taking off the mesh.

Anyone have comments on hot burns or the shaggy bark? I imagine burning paper and cardboard can clog the mesh fairly easily. I wonder if the bark (its really shaggy/hairy) is the culprit?

Thanks, Jeff
 
This falls in the same quagmire as cat vs. non cat, steel vs. poly brush etc.
I have screen and have no problems with clogging.
I will say, if you have screen on there with smaller than say 1/2" square holes, and wish to keep a screen on there, remove the smaller holed screen and put one that has 1/2" to 3/4" holes.
Makes a big difference.
 
MogollonMonster said:
Been running my Oslo for two months now. This morning I got up to restart and had smoke escape from the side door. After playing around with it a bit I could tell it wasn't drafting well. Got out the ladder, got up on the roof, fought through the snow, and checked the chimney cap. The mesh was plugged. I cleaned it out which solved the draft problem.

For the first month I ran poorly seasoned oak and well seasoned aspen. I had to keep the air supply mostly open with the oak to keep the fire hot enough. I ran hot fires with the Aspen and had to closely monitor the air supply to keep from over-firing. After one month, I inspected the cap and inside the chimney. There was no noticeable build up at that time. For the second month I burned mainly pinon and aspen, both seasoned. Recently I got a load of shaggy juniper which seems dry enough. It's very easy to start a fire unlike the oak. I've been running the stove with the air supply partially closed down with the juniper. The stove temps range between 450 and 550 and I get really good secondaries. Better than any of the other wood I've tried.

Couple of questions.

1) Could the shaggy bark on the juniper cause the plugged cap? I kind of doubt it . . . more likely it is the moisture from the wood cooling down and forming creosote . . . and unfortunately you will get some creosote with most wood . . . even well seasoned wood . . . just a lot less of it . . . and of course with unseasoned wood the likelihood of having more creosote will increase.
2) If you run a hot fire will it help keep the cap clean and if so how hot? Yes and no . . . running the fire hot enough to keep temps up in the flue regularly will help prevent the formation of creosote . . . but as mentioned some creosote formation over time is almost inevitable . . . as to having a single hot fire to "clean" out the chinney . . . not recommended . . . danger of a chimney fire.
3) Any thoughts on removing the mesh? I'm not a big fan of small mesh blocking chimneys . . . seems like there are way too many issues with creosote and even light-weight fly ash blocking fine to small mesh openings. On the otherhand you probably don't want a Flock of Seagulls or other birds or 1980s vintage bands taking up residence in your chimney over the summer . . . me . . . if I had a problem like this would probably take some snips and open up the mesh a bit more, but keep enough in place to block out most critters.

Any other suggestions are appreciated. I'd like to minimize my number of winter trips on the roof.

Thanks, Jeff
Click to expand...
 
I have issues with Creosote and my cap but I'm burning western softwoods which have more creosote forming VOC's than most hardwood species even when dry I'm noticing. I burned about half a cord of locust earlier this year and no creosote in about 2 months then switch to 2-year seasoned Red fir and the cap plugged up in about a month and a half but the stove pipe was relatively clean.

I've just consigned myself to cleaning the cap every month or so and it's worked just fine. I also have a relatively short chimney (13-14 feet) which may play into this.
 
LLigetfa said:
Carbon_Liberator said:
Cutter said:
In the past I also had some similar problems. I have a very large fireplace and tend to not burn hot enough. Towards the end of my burning seasons I started having the same issue. I have a very tall and steep roof 14/12 pitch. The chimney sticks up over 7 ft above the roof surface. So it is very difficult not to mention dangerous to go up there in the winter. I probably shouldn't be telling this here to some of you folks but I started using a .22 cal. rifle with bird shot to knock the screen clean. No neighbors no chance of hitting anything else. One shot per side and all was well till the end of the season. I have basically no creosote in the clay fluepipe just on the cap screen. So last fall I took some tin snips and enlarged a hole on each of the four sides. This has worked well for me. OK flame me
Brad
Click to expand...

GASP!!! :ahhh:
Click to expand...
Those .22 cal bird shot shells are so ineffective, you are unlikely to kill a squirrel with one at 20 feet. Good for shooting mice inside the cabin.
Click to expand...

That is truly great. I never heard of that one before. On first read it sounds dangerous. Then I remembered us being shot at with salt shot in NC by a shotgun (not sure what size) from about 100 yards (I guess the "No fishing, private lake, you will be shot" sign was not a joke) anyhow a few of us got hit in the back and at that distance the salt didnt even rip our clothes. It just stung a little. Needless to say, you hear the shots and you feel something hitting your back (that shot must have been real spread out by then) and you just keep running. We all fully expected to stop and find ourselves bleeding to death. What a laugh we got when we just saw little marks on the backs of our shirts. Still, we didnt go back to that lake to fish.
 
I remember the first time I even heard about birdshot in a 22 when I was a little boy. The neighbor had some and he shot a sparrow at about 25 feet and all it did was stun the bird for just about 2 seconds and then it flew showing no sign of harm. It is pretty harmless stuff. It would be funny to shoot at the cap and have a few neighbors see you do it. lol

Along that same line, I've used a .22 to shoot down into a well that had a sand point. It sometimes will clean the point out quite nicely. I told someone about this when he had the problem. The next time I saw him he told me that it didn't work so he got out his 30.06. That must have been exciting! He drilled a new well.
 
Carbon_Liberator said:
Cutter said:
In the past I also had some similar problems. I have a very large fireplace and tend to not burn hot enough. Towards the end of my burning seasons I started having the same issue. I have a very tall and steep roof 14/12 pitch. The chimney sticks up over 7 ft above the roof surface. So it is very difficult not to mention dangerous to go up there in the winter. I probably shouldn't be telling this here to some of you folks but I started using a .22 cal. rifle with bird shot to knock the screen clean. No neighbors no chance of hitting anything else. One shot per side and all was well till the end of the season. I have basically no creosote in the clay fluepipe just on the cap screen. So last fall I took some tin snips and enlarged a hole on each of the four sides. This has worked well for me. OK flame me
Brad
Click to expand...

GASP!!! :ahhh:
Click to expand...

Most call those .22 shotshells RAT SHOT........hard to kill a bird with em.........A+ for ingenuity
 
MogollonMonster said:
I only have a 12-gauge and I am sure the neighbors wouldn't appreciate it. I'll think about taking off the mesh.
Click to expand...

I bet that 12-gauge would about take the mesh off though... and the cap too depending on how high/far away it is eh?
 
Slow1 said:
MogollonMonster said:
I only have a 12-gauge and I am sure the neighbors wouldn't appreciate it. I'll think about taking off the mesh.
Click to expand...

I bet that 12-gauge would about take the mesh off though... and the cap too depending on how high/far away it is eh?
Click to expand...

PROPLEM SOLVED REPLACE IN SPRING!!
 
monster, As others have said, be prepared to have birds in your stove this summer unless you have some sort of screen in the cap. A bird in the stove will make a heck of a racket, especially at night. When living in Idaho my chimney cap had no screen and each year I had about three or four swallows come down the chimney into the stove. They were unable to fly up the chimney. As I recall, I had a double wide front door and the front of the stove faced that door. I would open both of the front doors, then the stove door and stand back. The swallow would explode out of the stove in a cloud of ash dust, make a few laps around the room and then beat it for the outdoors. Apparently they never told their friends about the hazards of looking under a chimney cap for a nesting site.

The screen on my current chimney cap has 1/2" mesh. If it should ever clog I will first review what I am doing wrong with the burning then replace the current screen with a 5/8" or 3/4" version. John_M
 
To chime in with the others who mentioned 1/2in mesh- I have a home made cap here and I also use galvanized wire cloth with 1/2in openings. It has never come close to clogging up. Sometimes I see just a little soot building up on the wires. A few strokes with a wire brush and it's clean. I'm blessed with a single story house with a shallow pitch roof. It's real easy to climb up there often at the beginning of the season. I've become convinced that it's going to be near impossible for me to clog that screen.

I'm burning the typical 'hardwood mix', heavy on the Red Oak. It's pretty well seasoned. For whatever it's worth, my screen is horizontal, with the rain cap above it. Perhaps that makes a difference. I believe that the expanded metal screens with their flat parts just 'want to clog' more, and that round wire grids tend to shed passing soot and creosote better. Thinner wires seem to make less of a target for particulate to latch onto.
 
Status
Not open for further replies.

Similar threads

R
Spark arrestor plugged?
Replies
6
Views
609
The Hearth Room - Wood Stoves and Fireplaces
Trevor Tahclep
Trevor Tahclep
BC_Josh
Had a chimney fire this morning
Replies
14
Views
1K
The Hearth Room - Wood Stoves and Fireplaces
BC_Josh
BC_Josh
ERP
Chimney Air Kit
Replies
1
Views
199
The Hearth Room - Wood Stoves and Fireplaces
bholler
B
N
Embers in flue elbow
Replies
1
Views
421
The Hearth Room - Wood Stoves and Fireplaces
begreen
begreen
T
Bird Proof Chimney Cap???
Replies
17
Views
3K
The Hearth Room - Wood Stoves and Fireplaces
Eman85
E
Top Bottom
Back