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Nobadays
Member
# Posted: 27 Dec 2019 22:07
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Went to town yesterday.... before we left I had stoked and shut down our stove.... like we do every night and when we go to town. Earlier that morning I was taping the stove pipe to get the creosote to fall down and burn up. We use a chemical regularly that is supposed to crystallize the creosote and make it break loose from the pipe... it works.

The biggest issues with our stove pipe are... one, it is put in upside down, the female ends face down so creosote can run out of the joints.... bad. Secondly, the stove has a 6" outlet but the PO ran 8" from the stove about 15' up to the ceiling.... should be 6" with an increaser to 8" where it passes into the triple wall pipe. Lastly, as we found out yesterday, there were no screws in the slip joint.

So here is what happened. The weight, my periodic taping to drop creosote and the no screws in the slip joint lead to the adapter that screws in to the triple wall pipe to unscrew and drop down about 6 inches at the slip joint. When we came home from town we could smell creosote, the stoked fire had produced a lot of creosote. The creosote had run down the pipe in several places, apparently greasing up the slip joint allowing the pipe to drop. The pipe is rough looking...

The house smelled but not a great deal of smoke, couldn't have come loose to long before we came home. We emptied the stove, called a neighbor and we were able to get the pipe raised and screwed back into the triple walled pipe. Put a couple of screws in the slip joint to keep this from happening again.

Other neighbors are coming up tomorrow to run a brush down the chimney... we will get by this winter, but definitely are going to fix this right next spring! Scary!

ICC
Member
# Posted: 27 Dec 2019 23:21 - Edited by: ICC
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Quoting: Nobadays
the stove has a 6" outlet but the PO ran 8" from the stove about 15' up to the ceiling.... should be 6" with an increaser to 8" where it passes into the triple wall pipe.


If I understand that correctly... you are stating the stove has a ^" exit but the main part of the chimney is 8" then.....

If the stove was made for 6" pipe, the installation should be 6" all the way to the top, no increases at all. The increase from 6" diameter to 8" diameter is an increase of over 75%. What that means is when the exhaust hits the 8" diameter the gases slow down by 75%. That can lead to greater creosote buildup. It can also make for a stove that doesn't draw as well as it should.

FYI, many if not most stoves now use 6" flues instead of 8" like most stoves used in pre-EPA years. This is because the greater efficiency of the newer stoves means they don't have as great a volume of exhaust passing out the chimney. So the mfg reduced flue size to maintain a good draft.

Glad there was no building fire.

darz5150
Member
# Posted: 27 Dec 2019 23:31
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You said the pipe was upside down. Is the connection on the stove male or female? Ours is male and the pipe slips over it.

Nobadays
Member
# Posted: 27 Dec 2019 23:52
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ICC.... yes it should be 6" all the way. Unfortunately the triple wall through the roof is 8". I think if I reduce the pipe to 6" up to the triple wall this will help.

Darz... male sticking up from the increaser at the stove. So female down the rest of the way up. Creosote running down the outside of the pipe.

ICC
Member
# Posted: 28 Dec 2019 00:05 - Edited by: ICC
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Quoting: darz5150
Ours is male and the pipe slips over it.


That is wrong. The male end should fit inside that connector. The female end may slip over the outside but it is incorrect installation.

Woodstove pipe, single wall black pipe, should always have the male end pointing down, towards the stove. Some pipe is sold with "flow" arrow stickers to help figure out the correct orientation. The crimped (male) end down so that anything that may run down the inside of the pipe is directed to stay inside the pipe. Creosote deposits can liquify under the right conditions, or burning green wood can cause condensation and you can end up with black crud running down the outside of the pipe.

With an insulated pipe, it may appear that the male end is pointing up, but a careful inspection will reveal that the down-pointing inner wall is inserted inside the next lower connecting section. On the exterior of the insulated pipe, the bottom end of the upper section may overlap the top end of the lower section, in order to keep rainwater on the outside of the pipe.

ICC
Member
# Posted: 28 Dec 2019 00:11
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See #12 in this link.

darz5150
Member
# Posted: 28 Dec 2019 00:42
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ICC. Not doubting your link at all. But when I first read the OP. I looked at ours knowing the orientation. So I did a quick search. And it seems opinions vary.
https://www.homesteadingtoday.com/threads/which-way-do-you-run-your-stove-pipe-and-wh y.387922/
Some of the posts say one thing. And further down the list are people quoting Fire Marshalls saying the opposite.
We have a cast iron stove. And the connection at the stove is tapered. I have a crimping tool, but if I crimped the pipe enough to fit inside, it would probably leak like sieve even with tape. Also I think the rain cap is female. Again. Not saying its right or wrong. But we've never had a problem.
Ours had to be approved by the home owners insurance co.
I'm not gonna change anything since its worked fine. But it kinda makes me wonder.

Brettny
Member
# Posted: 28 Dec 2019 07:18
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Well I would say you need to take a serious look around your place for wood stove/fire safety. I would also say that that chimney cleaning chemical didn't work.

Former hunting camp almost burnt down one year. For some reason when building they ran the center girder for the second floor into the fireplace stone. 40yrs later it started to burn. It required quick demo of a bed that was built over the area and chainsawing away the floor. Just proves that just because it was ok for 40yrs didn't mean it will be good for another 12 months.

Nobadays
Member
# Posted: 28 Dec 2019 09:10
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ICC.... you are absolutely correct IMHO. I have had wood heat as primary heating source for a good 40 of my 65 years.... I'm NOT NEW to wood heat! I have installed several stoves and changed pipe numerous times. I always orientate the pipe with the Male ends down. Creosote happens, I want to keep it in the pipe where it can burn out.... in a controlled manner preferably. I have had one chimney fire in 40 years of wood stove use and that was enough adrenalin!

I am burning dry Aspen. It was either standing dead or down dead, anything punky is on the slash pile. I do not have a moisture meter but this wood has been split and stacked, and covered with tarps since last fall. It is light and seems very dry.

Yet when I bank a fire at night the smoke is condensing and creating creosote which is running out of the pipe mostly in the first 6 feet or so. There is an increaser on the woodstove from 6" to 8".... male x male, so Male end up. This has a 4' piece of 8" female end down... creosote leaks a little from here maybe. On top of the 4' piece is about a 1' piece used as the slip joint, female end down and definitely leaking creosote. This 1' piece has another 4' piece on it, female end down, it most definitely is leaking creosote. 2 more 4' lengths of pipe above the one attached to the slip joint, both have a few rivulets of creosote that has leaked but not much and does not look recent. These last 2 lengths attach to another 1' length of pipe that is attached to the adapter that screws into the triple wall going through the roof. Hard to see but I believe the adapter must have a Male end down. The PO cut off the 1' length of pipe leaving a female end down then forcing the raw end over the adapter. No creosote present or leaking here.

As far as the chemical not working, I don't agree. If I tap the pipe creosote that is clinging to the inside dislodges and falls down the pipe. This is exactly what the chemical is intended for. It helps to crystallize the creosote and weaken the bond to the pipe so it will fall down and be burned up... or make it easier to brush out.

My observation is that the smoke seems to be condensing and creating creosote primarily within the first 5' - 6' out from the stove... when it is shut way down for night.... or when going to town. This leads me to believe the increase to 8" pipe right at the stove is allowing the smoke to cool way to fast because there is too much room in the pipe for it to draw well with a very low fire. I believe this stove was intended to have 6" pipe all the way up. I must say we get no smoke out the door when it is opened so it is drawing OK but it is not right... it is installed incorrectly and is dangerous.

I had hoped to wait until spring when we don't need a continuous fire to fix this but I feel this needs done now. Of course the snow is quitting today and the single digit temps returning... nice!

Here is a picture of my mess...
Chimney mess
Chimney mess


ICC
Member
# Posted: 28 Dec 2019 10:25 - Edited by: ICC
Reply 


Yikes! That is a messy chimney, in more than one way. Yeah, it really should have a re-do. Ideally, I believe it should be a run of new pipe, 6" all the way.

Perhaps there is a safe way to use a S/S liner tube inside the 8" insulated pipe? If possible it might be easier than replacing all the 8" pipe and not require changing the support and the roof flashing.

I use a telescoping length of black pipe similar to this one. It connects to the stove at the bottom and to an 18" length of insulated pipe that drops from the ceiling support box. Three screws fix it to the insulated pipe. My cleaning method is to have the stove cold. Push the lower section of the pipe up a few inches and then remove the screws and pull the upper end loose from the insulated pipe. That pipe then gets taken outside. A HD plastic garbage bag is taped to the pipe end hanging from the eiling. Go up on the roof that has ladder rungs permanently attached to the metal roofing. Pull the cap off. Run the brush down and then back up. Maybe one more time down and up. All the crap falls into the bag and gets taken outside. Reassemble the telescoping pipe after using a shop-vas to clean out the top end of the stove. I usually use the shop-vac to also clean any asg out from the lower ash tray. There is usually some that escapes from the tray and clutters up the tray slide.

We had wood heat in the old house I was born into. The first chores I remember was bringing in wood to burn. I stopped burning wood as primary heat when I built the present house 5 years ago. So that makes 74-5=69 years of wood heat.

Nobadays
Member
# Posted: 28 Dec 2019 11:16
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ICC... my interior chimney pipe is about 17' of single wall. Not ideal. Not having much experience with cathedral ceilings, at least where the pipe goes through the roof near the peak, I'm not sure if this is too much single wall pipe anyway. It would seem more appropriate to have double wall down from the ceiling at least 8' - 10' leaving only 7' - 9' of single wall. The problem woul be how to support the double wall pipe.

I think your idea of a liner is great, probably best. That said I think I will run 6" from the stove to the triple wall and use an increaser right there to the 8" pipe. That will undoubtedly be the place creosote will build and possibly plug so it will need cleaned frequently. We have plans to affix a ladder to the roof come spring, knew we needed it but just couldn't get to it last fall... should have been a priority!

I just called every store anywhere near us and no one has heavy guage... or any for that matter... 6" stove pipe other than 2' lengths. Apparently they never restocked after the fall stove installations.... crap!

Down the hill to talk to the neighbor about getting up on the roof and cleaning the chimney.

Thanks for your help/ideas... appreciated!

Nobadays
Member
# Posted: 28 Dec 2019 17:04
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Neighbors came over and we took the stove pipe outside, brushed it out really well.... only stuck on creosote was in the he last piece near the ceiling, about 18" pretty baked on creosote. The rest of the pipe whisked out with one pass.

We swapped the top piece with the bottom section effectively turning the whole pipe upside down so now the Male ends are down. Any creosote that liquified will run back down, inside the pipe where it can burn up. The top of the firebox below the pipe had a huge pile of burned creosote ash! That was also cleaned out. Stove draws even better than it did!

Still not right.... it still should have 6" pipe all the way out, at least to the triple wall that goes through the roof. It will be changed, but at least we are in good shape for now and won't likely burn our cabin down!

Shower night... whoopee!!

ICC
Member
# Posted: 28 Dec 2019 17:23
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If you have the stove manual, or if you can find it online read what the mfg says. I just looked at the manual for the present VC stove I have. It states a maximum of 8 feet of single wall pipe from the stove exit. It also states 6" or 8"is okay. The old stove wanted nothing but 6". So I guess the pipe size can vary depending on what the mfg figures are best. You may be okay. I surprised myself when I re-read the new stove manual.

Nobadays
Member
# Posted: 28 Dec 2019 17:39
Reply 


Thanks! I'm surprised as well that 8" is acceptable. I'm not surprised that there is a maximum of 8' of single wall. Makes perfect sense. Smoke is not going to stay hot for the 17' from our stove to the triple wall pipe. I need to look into double wall pipe and how to support it. Maybe off a beam that is at about the 8' level. The beam is about 2.5' away from the pipe so the support would have to be pretty strong to hold up 10'+ of double wall pipe.

Oh... btw I wasn't questioning your knowledge or years of experience with woodstoves. I learned quite quickly on this forum that you have knowledge and experience that can be trusted. By stating my years of woodstove use I was only trying to demonstrate that I do have some knowledge and experience myself.... but certainly not an expert!

Thanks again!

ICC
Member
# Posted: 28 Dec 2019 18:44
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Quoting: Nobadays
Oh... btw I wasn't questioning your knowledge or years of experience with woodstoves. I learned quite quickly on this forum that you have knowledge and experience that can be trusted. By stating my years of woodstove use I was only trying to demonstrate that I do have some knowledge and experience myself.... but certainly not an expert!


I was sort of kidding you with that, being that I grew up with wood heat. That house never had any central heat at all, just cast iron wood burning stoves, kivas and a wood burning cookstove in the kitchen. @ wood burning cookstoves; one in the inside kitchen for cold weather use and one in the outside "summer" kitchen. Lots of chimneys and flues.

darz5150
Member
# Posted: 28 Dec 2019 20:47
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Just to clear things up.
Quoting: ICC
That is wrong. The male end should fit inside that connector. The female end may slip over the outside but it is incorrect installation.

This is the first instruction for flue installation.
Screenshot_2019122.png
Screenshot_2019122.png


ICC
Member
# Posted: 28 Dec 2019 21:33 - Edited by: ICC
Reply 


That does agree with the information I posted.... crimped end towards stove. It sounds like that stove mfg may supply some sort of a special pipe that is supposed to be used to connect to that stove outlet. Not that every stove should have the smooth, non-crimped end connect to the flue collar. If one places the smooth end of a standard single wall pipe to the stove flue, how then could they connect crimped ends towards stove on the rest of the pipe lengths?

darz5150
Member
# Posted: 28 Dec 2019 22:23 - Edited by: darz5150
Reply 


By cutting off the crimped end before inter locking the seam. Then putting the crimped end of the next pipe towards the stove.I mean no disrespect at all by posting this. Actually the opposite. I know you have a lot of knowledge that your openly share. But you had me wondering after the above quote. How the inspector and the insurance company would sign off on an incorrect install. The pipe either can go inside the connection like you said. Or outside (over) the connection as per instructions. Again. No disrespect meant. Hopefully none taken. But the install is correct and was signed off as correct.

ICC
Member
# Posted: 28 Dec 2019 23:38 - Edited by: ICC
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No offense taken.

So I got real curious and read the NFPA rules on chimneys. NFPA211. There is no actual rule that states the crimp end should face down. I never realized that before. The NFPA rules are mainly concerned with clearances from combustibles, using proper materials (no galvanized single wall pipe is mentioned) and installing supports, etc so nothing falls apart, along with a sprinkling of references to follow other rules and manufacturers instructions.

There would seem to be some discretion given to what an inspector will call okay or bad. Inspectors do have some leeway on calls but can never change code. So, if as it seems, the direction of the male end connector is not codified the inspector can do as he sees fit.

It does seem that if you purchased pipe that came with flow direction arrows or written instructions that state crimped end down, there would be cause for argument. Manufacturers' instructions do usually win in a code argument. I do really wonder about that method of connecting the first pipe length to the stove collar though.

FWIW, inspectors are human. Every so often one may make a wrong call, it is a fact of life. However, some inspectors misinterpret rules. We had one bldg inspector here about 15 -20 years ago who got it into his head that we could not build exterior walls with 2x4's anymore. We had to use 2x6's. He was red flagging people for 2x4's. He came to that wrong conclusion because the codes were changing and stating that walls needed to be R20 or more. You can't get R20 insulation stuffed into a wall cavity, that is pretty much true. But you can add insulation like sheet foam over the framing and achieve the required R-value and use 2x4 framing. A small group of us had to go talk with the county commission in order to straighten him out. The point of this diatribe is simply to point out humans make errors.

I'd probably seat that stove end of smooth pipe in a good bed of stove cement.

How old is the wood stove in question?

Looks like I need to go run the snowblower tractor before I go off to bed. That'll make the morning easier.

Let's say the installation at the stove collar that has been mentioned is not wrong, as it follows the mfg directions; but it does sort of defy the common sense logic of how all the other joints are connected.

Nobadays
Member
# Posted: 29 Dec 2019 08:50
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I don't want to muddy the waters, and as ICC has said you need to follow the manufacturer's directions. I did find an installation manual online for my stove - VC Aspen - here is what they had to say.

"Assemble the connector beginning at the flue collar, with the crimped ends pointing towards the stove (to keep debris or residue inside the system)."

As far as pipe diameter, I believe I need to stick with 6" pipe...

"The chimney connector diameter should correspond to the size of the flue collar opening. Do not use makeshift compromises."

And yep... 17' of single wall (they are calling this "connector" as in from stove to chimney) exceeds their recommendations by about 7'...

"....the total length of connector should not exceed 10 feet (3m). "

It is apparently fine to vent into the existing 8" triple wall that passes through the ceiling....

"This stove is approved for venting into a masonry chimney with a nominal flue size of 8" x 8" (203 x 203 mm), and into a round flue size of 8" (203 mm) or 6" (152 mm)."

Looks like my biggest issues are, too large of connector pipe... should be 6" and too long of run of single wall/uninsulated pipe.

With the other woodstoves I have used over the years they have either vented into a masonry chimney or have been near a wall with correspondingly short runs of single wall pipe. This cathedral ceiling with a 17' run of pipe just to get to the chimney is all new!

A neighbor.... who consequently had a nasty, but non damaging flue fire recently has an interesting installation... dangerous in my opinion. The stove sits near an outside wall yet the chimney penetration is near the peak. So the installer ran the pipe straight up to within 18" of the interior sloped ceiling, put a 45* elbow then continued to follow the slope of the ceiling up to the chimney where another 45* elbow directs the pipe into the chimney. I was at their cabin the day before they had the flue fire, the place was smokey and they were complaining that the stove wouldn't draw. Apparently the creosote had built up in the triple wall and in the upper stub of pipe/45* elbow, so much so they were nearly completely blocked... said when they pulled it down you couldn't pass your hand through the pipe or elbow! It is amazing how well their stove draws now! Still not a pipe run I would like but looking at the installation guide for my stove it would meet the requirements except for too long of run of single wall pipe... the angle is fine and 2 x 45* elbows are acceptable.

Thanks for the discussion... if nothing else it made me go find the manual and read how to properly install this particular stove.

ICC
Member
# Posted: 29 Dec 2019 15:02 - Edited by: ICC
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Quoting: Nobadays
I did find an installation manual online for my stove - VC Aspen -


Wow! Nice stove. I either forgot, or you never mentioned what you had. I have owned one, and 2 friends each have one too. One of them installed it with a high cathedral ceiling, something like the 17 feet of pipe you have. He had a hell of a time until he replaced about 8 feet of single wall pipe with the insulated pipe. All 3 of us ended up installing the fresh air inlet as well and found that helped its draft a lot. That's only an issue if the cabin is very airtight.

paulz
Member
# Posted: 29 Dec 2019 15:32
Reply 


So what happens when a metal stove pipe catches fire? Blow the metal apart, shoot out the roof?

Nobadays
Member
# Posted: 29 Dec 2019 16:22
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ICC... yep I really like the stove. Don't have the outside air inlet but apparently we are drafty enough as the stove draws exceedingly well. It has been a learning curve with the toughest lesson being the front air inlet plugged with ash. The stove would hardly burn when we bought the cabin and leaving the door cracked open was the only way to get enough air to it. Started researching the stove (hadn't found the manual at that time) and found out how the draft system works and the fact you need to periodically clean out the ash under the plate just inside the door. Cleaned the ash out and wow what a difference!

Maybe you know the answer.... would the double wall pipe with an air gap as insulation, but no actual insulation be sufficient to replace the top 10' of my run? The insulated pipe I have found is all the expensive stainless steel stuff... I would rather not have that in the cabin. Thanks!

Paulz... my only chimney fire was in a masonry chimney, but I have been called out as a volunteer firefighter on several chimney fires in the metal pipe. I've never seen it blow apart but I've seen it glow red! It's a scary thing even for a firefighter as you can't put water on it or it can collapse and burst. Our SOP was to send two guys on the roof to put VERY SHORT bursts of water into the chimney if there was fire up there, otherwise just stand by, two guys in the attic to make sure there was no fire breaking out up there, lastly open the stove and shoot a VERY SHORT blast of water then close the door rapidly and let the steam put out the fire. I'm not sure I would recommend putting water directly into your woodstove.... that is how our fire department operated but I have since heard that is not a good method. Though I must say it worked. We would then help the homeowners take apart the stovepipe and brush it out for them. BTW a town of only 1,200 people so we could do those things...

Currently by our stove I keep a box of FireEx. It is a chemical extinguisher that you just throw the box into the stove and as it burns it emits.... something... that puts out the chimney fire. I don't know how well it works and hope I never have to use it. Good reviews online so I got a box. Last resort... yep I'd throw a glass or two of water in the stove to create steam... right or wrong I've seen it work many times.

ICC
Member
# Posted: 29 Dec 2019 17:27
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Quoting: Nobadays
would the double wall pipe with an air gap as insulation


This is a guess... if the stove has no problems riggt now with the draft, then I would think the double wall / air-gap type would be okay. I have only used the S/S pipe insulated with rock wool or whatever. Yes, it is pricey but it does hold the heat inside the inner pipe very well.


Regarding chimney fires... our fire dept carried plastic bags of sry chemical extinguisher powder. They go up on the roof, twist off the cap and drop a couple bags, more if needed. They sometimes shoot a dry chemical extinguisher in the door of the wood stove. Never water according to the guys I know in the dept.

Nobadays
Member
# Posted: 29 Dec 2019 18:11
Reply 


ICC... That's kind of what I'm thinking. The stainless insulated would probably be a better choice but the double wall with the air gap should allow more heat to carry up the chimney. The primary use for that type of pipe is to allow the pipe to be closer to combustible materials, so it must keep a good deal of the heat inside.

I think dry chemical is likely a much better choice, not the chance of the water cracking fire brick or cast iron. I haven't been on a fire department in 35 years... our method then would be considered old school I'm sure! Old school isn't always best!

hamish
Member
# Posted: 29 Dec 2019 19:28
Reply 


WOW, cant say anymore. Half you would die here.

Nobadays
Member
# Posted: 29 Dec 2019 21:08
Reply 


Hmmm... that's kind of random, and not helpful. But I have to disagree, I survived nearly a month in Scotland last year... the whiskey was great and the haggis not bad.

hamish
Member
# Posted: 30 Dec 2019 18:45
Reply 


Its pretty simple. A single wall stove top adapter is whats used, and the crimped end goes into the stove collar.
Look up a Metal-Fab SWA-1 for example.

Nobadays
Member
# Posted: 30 Dec 2019 19:21
Reply 


Hamish.... Thank you!

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