Chimney cap fire!

[Lumber-Jack]

Lots of unburnt wood gases (smoke) exiting the chimney at under 250F is a guarantee for creosote buildup. Instead of smoldering, burn shorter hotter fires.

That's good advice Begreen, but other factors obviously at play here. The only creosote issue I seem to have, and the main topic of the thread, is the small amount of creosote that deposits on chimney caps, and the fact it can ignite. In my case that only seems to be happening on my EPA stove where I do burn very cleanly (hot, non-smoldering fires), evidenced by the fact that the chimney itself had no significant creosote build up. The stove in the shop, where I have smoldering fires sometimes, hasn't had that problem, likely because of the shorter chimney, and because it just gets less use.
In reality, it makes sense that any cap will get more deposit than the flue itself since the flue is insulated, and the cap is just a thin un-insulated piece of metal that sits on the very top of the flue where the smoke has had the greatest opportunity to cool down. The longer the flue, the greater opportunity that smoke is going to have to cool down, and since the cap is so exposed to the cool air it's basically going to act like a creosote magnate when the smoke flows past it.

 

[rideau]

My pipe is about 8 years old now. Have never had any creosote on the cap or screen, never had anything to clean out of the chimney except in the stovepipe section. Cup or two a year. Long chimney, interior, ICC pipe. Burn at moderate stove temps (usually in the 350 stove top temp range), flue temp 500 - 600, because I need to get a damper....

 

[lopiliberty]

Had the same problem a few week ago although I don't use a cap on the flue when burning 24/7. Started a fire one night got it going good and happened to look out the window and embers not sparks where raining down from the sky. I think it was just the locust kindling and locust splits popping and snapping because I check this flue every Thursday when I clean out the ashes and it is completely spotless and the last time it was cleaned was November. I actually had to go out and stump out some of the embers

 

[etiger2007]

I know all installs are different but I NEVER have any accumulation of creosote on my cap and my uninsulated liner only has a thin coat of powdery soot. My wood supply is marginal at best except what Savage gave me, my wood ranges from 20 to 22 % moisture.

 

[Lumber-Jack]

I know all installs are different but I NEVER have any accumulation of creosote on my cap and my uninsulated liner only has a thin coat of powdery soot. My wood supply is marginal at best except what Savage gave me, my wood ranges from 20 to 22 % moisture.

I find that hard to believe that you have zero creosote accumulation on your chimney cap. Very little maybe, but "NEVER any" seems pretty remarkable. Could you provide pictures of this exceptional cap, maybe I'll switch caps. Seriously.

I kind of regret not taking a video of by burning chimney cap now.

 

[etiger2007]

I find that hard to believe that you have zero creosote accumulation on your chimney cap. Very little maybe, but "NEVER any" seems pretty remarkable. Could you provide pictures of this exceptional cap, maybe I'll switch caps. Seriously.

I kind of regret not taking a video of by burning chimney cap now.

Yup Ill take one when I get home from work.

 

[etiger2007]

Yup Ill take one when I get home from work.

This is hands down the worst my cap has ever looked, this was after my first year of burning, burning 10 month seasoned red oak, and no mid season chminey cleaning. Ok my cap dosent look like I just bought, My cap looks better now that my wood is seasoned and I have a better understanding how to burn clean fires.

 

[Lumber-Jack]

This is hands down the worst my cap has ever looked, this was after my first year of burning, burning 10 month seasoned red oak, and no mid season chminey cleaning. Ok my cap dosent look like I just bought, My cap looks better now that my wood is seasoned and I have a better understanding how to burn clean fires.

Thanks for posting the picture Ed, I gota tell you though, my cap didn't have an awful lot more creosote build up on it than what I see on yours. The top center area of your cap looks like the creosote area that had the burning ember area on my cap, just a bit thicker though. It was however wetter looking, as I mentioned at the start of the thread, the wetter creosote I've noticed forms when it's windy and cools the cap more. I notice your cap seems taller too, so it is physically further away from the flue exit, so that is might be another reason why it gets less creosote deposits.

 

[etiger2007]

Your welcome Randy, Must have been a freak thing where an ember got caught just right.

 

[clemsonfor]

I hope my neighbors cap never catches fire, he has about a 5" creosote cickle hanging off of it

 

[Lumber-Jack]

I hope my neighbors cap never catches fire, he has about a 5" creosote cickle hanging off of it

This is what gets me about all this, my flue was clean and I only had a light coating of creosote on my cap, and yet it was enough to ignite. Other manage to let it go until there caps are plugged and they seem to be fine.
Guess I'm just the lucky one. This is why I clean my chimney regularly.

 

[Trickle]

Randy, love the system you have. I am considering a metal roof and that was one of my concerns was how to service the chimney. Any more details on your system to get out and get back?

Thx,
Trickle

 

[Lumber-Jack]

Randy, love the system you have. I am considering a metal roof and that was one of my concerns was how to service the chimney. Any more details on your system to get out and get back?

Thx,
Trickle

Hey trickle, that video pretty much shows it all, not too much to it. I could take a close up picture of the roof brackets if you'd like although they are pretty simple too. I made them myself and painted them to match the roof color and secured them to the roof permanently. Having that attic area accessible from that other roof where I can store the planks, ladder and chimney cleaning rods and brush makes things a very convenient, but the main thing is having a way of getting access to the flue, which was really difficult before I installed the roof brackets. The roof is steeper than it looks in the video, and impossible to walk on on otherwise, and any metal roof is super dangerous to walk on if it is wet or frosty, even if it has just a slight slope.
My shop, which also has a wood stove and flue, has the same metal on the roof, although it has a regular 4/12 pitch, so I can walk on it without any special brackets, but I have to wait for a time when the roof is completely bone dry, any snow or frost on the roof and forget about it.

 

[Trickle]

Randy, if you have a chance next time you are up there to grab a pic of the brackets that would be great. No rush though, I have to buy the place first before I roof it. Looks like the brackets are made of angle iron and installed on top of and screwed through the metal roof?

I guess I thought you couldn't walk on a metal roof at all, not because of the pitch per se, but because most metal roofs I've seen installed are screwed to a one by grid of boards over the asphalt shingles. Seems like if I stepped on that it would dent in and collapse anywhere I wasn't stepping on the one bys. See the double bubble picture for what I mean. Instead, maybe your metal roof was installed flush with the plywood and over tar paper, similar to the installation2 picture.

So what are the planks made out of, wood? If so you might think about rigging something so the bars and brush are attached to the second plank, might save you one less trip up and down the ladder. And that antenna looks like a microwave internet receiver?

Trickle

 

[Lumber-Jack]

Tickle, it sounds like you are where I was about 5 years ago. We bought this old shack of a house with the intention of fixing many things and remodeling it, including a new roof. The roof was in very bad shape and needed a lot more than just some new metal roofing on it. There was (is) actually two different roofs joined together. The roof where the chimney goes through has a proper attic area, and beyond that is a chalet style second story with no attic space. To access to the attic space, where the chimney is, is through an access hatch in a closet off a bedroom upstairs.
First thing we wanted to fix was how the two roofs were joined together, it's hard to explain, but the two roofs didn't line up properly. To fix (hide) that, we raised the roof over the chalet style living area 2", and used that 2" space to add 2" of foam insulation. You can see a 2" brown cap where the two roofs meet.
Before doing that however, we stripped all the shingles off the roof, (1) to make it easier to frame the 2" height into the roof, and (2) to expose the sheeting to see what kind of shape it was in. Glad we did this because the top 4 ft of sheeting was in terrible shape and needed to be replaced.
Then, yes we strapped it all with 1x4" strapping.
You were mentioning walking on the roof, there are two things that you can do to make the roof strong enough to walk on. (a) Buy heavier metal roofing, (b) put your strapping closer together. In my case I did both. I didn't buy the thickest metal, but I got the step up from the thinnest I could get. (sorry, I don't remember the gauges). Also, instead of putting the strapping 2 ft apart as many do, I went 18" apart. If you calculate the difference in how many extra 1x4s you'll need, and the extra cost, I'm sure you'll see it's well worth putting the 1x4s a little closer together, and not have to worry about bending the metal if you step on it in the wrong place. Because you screw though the strapping to hold the metal roofing on, you'll use a few more screws too. This is good and bad, the good is that your roof will be more secure, it's bad cause you'll have to spend a few dollars more on screws.

Ok, on to the roof jacks pictures.
I'm also including some pictures of how I secured the ladder to the roof, and a picture of my chimney flashing on the shop. There was some discussion in this forum a while back about the best way to take care of the chimney flashing on a metal roof. You'll see that the flashing on the shop chimney looks nice and clean, and it's definitely water tight. Basically the way we did that was to cut a hole through the roof where the chimney goes through, install the chimney and flashing, then put another piece of roofing overlapping the chimney flashing and up under the ridge cap. I did the same thing on the house, but I used a black piece of metal roofing and haven't got around to changing it yet.
And finally a couple pictures of what the house and roof use to look like when we bought it, and what it looks like now.

Oh and yeah, you got it, microwave internet receiver. This post went through there.




Roof Jacks Notice in this picture you can see the little hooks on the ridge vent that hold the chimney brush and rods.
(broken image removed)

Ladder hooks
(broken image removed)


Shop chimney flashing
(broken image removed)


Old house and roof Notice the bump where the two roofs meet.
(broken image removed)

Updated house and Roof. Notice the closer roof is 2" lower that the area further back behind the chimney, separated by the brown cap.
(broken image removed)

 

[rideau]

Big improvement! Looks great.

Do you check the fittings regularly? Gather they are holding up well.

 

[Trickle]

Randy, you are right, I am exactly where you were 5 years ago, looking at buying an old shack to fix up.

That all makes total sense, thanks so much for taking the time and the pics. I learned a lot from you today and will put it into the roof of the new place.

The place looks fantastic, i even like the fish.

Thank you!

 

[Trilifter7]

This brings to mind the question if you guys use DW or SW inside pipe and how much difference in flue temps it could possibly make?

 

[Lumber-Jack]

Big improvement! Looks great.

Do you check the fittings regularly? Gather they are holding up well.

Thanks.
Not sure which "fitting" are you referring to? The roof jacks? They have 1 1/2" screws securing them, of course there's always the possibility could shear off.

The place looks fantastic, i even like the fish.

Thank you!

You're welcome,,,, keep us updated with your progress.

This brings to mind the question if you guys use DW or SW inside pipe and how much difference in flue temps it could possibly make?

I have double wall in the house, and single wall in the shop. So again, the house pipe aught to be warmer.