Found Puffy Creosote Yesterday...

[Battenkiller]

This is carried over from another thread, since I don't want to further hijack that thread....

[quote author="webby3650" date="1262043305"]Have you had your flue inspected? If you found "puffy" creosote there is a good chance you have some busted tiles in there. There are some exceptions but if I find one I find the other.[/quote]

Good question.

I was cleaning out my stove yesterday since it was too warm to need the stove. The stove was nice and white inside after a long slow burn the night before. Everything looked good, but I decided to try to get a look up the flue while I was at it. A mirror and light showed bright, clean metal all the way up to the elbow, but I couldn't see beyond that. I tried to get a look from the clean out door (lined masonry chimney). I couldn't get a good angle since the door is right behind the stove, so I figured it looked good enough for now. When I went to take the mirror out, I came up with some pieces of puffy creosote. Turns out the whole bottom trap was filled level with the bottom of the clean out door.

The landlord has a sweep clean the chimney once a year (usually in late fall). We've been here for almost 20 years and, as far as I know, the previous tenants didn't use this flue. Therefore, it must have been me, but at what point? I'm sure I made some bad mistakes with all this way back when, and I used to get yelled at by the sweep for burning wet wood at low temps.

The sweep (same one has serviced this chimney since I moved here) never mentioned anything amiss when he came this year. I work in the home, so I am always here to ask nosey questions and the guy said everything seemed fine. Before I installed the new stove I looked up with a light and mirror and felt around. The tiles looked fine at the lower end. I assume a chimney fire would cause most of its damage higher up.

There was no evidence of any broken tiles at the take out door. This would lead me to believe that any damage is not extensive. I also assume that these guys know their stuff. They just repaired the outer brick on the external portion of the chimney since it was starting to erode. Seems they would have mentioned any damage to the landlord since it would have, at the very least, put money into their pockets.

Your comments have me concerned. Is it possible to have a major chimney fire and not realize it? I've heard some tinkling in the flue pipe when I first got the stove, but I've been running it hot as hell since then... mostly good dry wood (2-3 year old stuff that came with the stove when I bought it). I was told that the VC Vigilant had a reputation as a major creosote factory, but that it was mostly because folks ran it way too cold because it was often installed in rooms too small. My basement install lets me run it quite high since that has been the secret in getting the whole house toasty.

I have run maybe a good cord of wood through this setup since mid-November. I used to run 4-5 cord through the same flue with my old stove and haven't had a big creosote problem since the early days of ignorance and sizzling red oak. I feel that I am doing everything possible to run this new beast properly. I would be both shocked and dismayed to find I have a problem since it seems to run so well compared to the old stove. Maybe the puff is from an earlier time and the sweep didn't get down below the door level and into the trap (seems to have been "leveled off" right at the bottom of the door). Or the guy cleans out the gunk and is not competent to make a good inspection (which doesn't seem likely since they design and build entire chimneys).

I will be calling another sweep and paying out of my own pocket for an extra cleaning, but I am concerned right now. Any advice will be appreciated.

 

[webby3650]

So do you have a SS lined masonry chimney, or lined with clay? You really need to get a good look from the top if you can. A very minor flue fire can cause great damage to some flues and not seem to affect others, the problem is that a crack that appears small and insignifigant has the potential to be devastating if you have another flue fire, since it may no longer be contained in the flue.

 

[Battenkiller]

Clay lined.

How do you detect a crack that "seems small and insignificant"? Is it something that can be easily missed by a pro? Would I smell smoke in the house during a routine burn? Can it be fixed? A new SS liner will be out of the question since I rent here. It would usher in the "electric era" for me.

I was accused of starting a chimney fire in my last place (over 20 years ago). I was burning in a huge wood furnace and when I got it cleaned and inspected, the inspection revealed a fire had occurred and that there was damage to the chimney. The landlord had to install a new liner for about $2500. Apparently, the law required him to get the chimney inspected every year (which he failed to do), so he had to foot the bill. We never got along after that.

I'll never know if it was me back then or a previous tenant. You had to burn wood in that drafty farmhouse, the electric woulda broken Bill Gates. The damage could have been ancient since the furnace had been installed about 50 years before hand. Easy to blame it on the messenger.

 

[webby3650]

Clay lined.

How do you detect a crack that "seems small and insignificant"? Is it something that can be easily missed by a pro? Would I smell smoke in the house during a routine burn? Can it be fixed? A new SS liner will be out of the question since I rent here. It would usher in the "electric era" for me.

I was accused of starting a chimney fire in my last place (over 20 years ago). I was burning in a huge wood furnace and when I got it cleaned and inspected, the inspection revealed a fire had occurred and that there was damage to the chimney. The landlord had to install a new liner for about $2500. Apparently, the law required him to get the chimney inspected every year (which he failed to do), so he had to foot the bill. We never got along after that.

I'll never know if it was me back then or a previous tenant. You had to burn wood in that drafty farmhouse, the electric woulda broken Bill Gates. The damage could have been ancient since the furnace had been installed about 50 years before hand. Easy to blame it on the messenger.

It is usually easy to see with a spot light. They often run the length of the flue. I doubt smoke would be entering the house, like your connector pipe, the flue would have a vacuum pulling smoke out and air in, not causing noticeable problems, but if you have a flue fire this could be a whole different story. In the NFPA 211 code book, cracked flue linings are condemned for a reason. The cracks cannot be fixed, a SS liner is the answer. Insurance will most often cover cost of the liner. You can buy a very reasonably priced SS liner kit these days, with the help of this site I am confident that you and a buddy could install this in a day. This would alleviate hard feeling with the land lord and you would sleep better. But remember, you might not have any problems at all in the flue, Got a spotlight?

 

[mnowaczyk]

BattenKiller:

I see you are a fellow risky clay lined fireplace burner. I have probably only run about 7-10 full days in my insert this year, but have probably been burning more wet wood than I should, especially with the clay liner.

How often to you check cor creosote in your chimney with your setup?

(I'm running a "slammer" install right now with 13x13 clay liner for about 35 feet of a 40 foot chimney, and I'm wondering how long I should go before getting the sweep out here... or biting the bullet on a ss liner.)

 

[Battenkiller]

Why do you use the word "risky"? Clay lined chimneys are great if they are in good condition, at least that's what I'm told. Mine draws fine, even though it is considered slightly undersized for my stove. I've been getting it inspected and cleaned yearly by the same guy for almost 20 years.


I just checked the flue yesterday after burning over 1 1/2 cord so far this year. I used a mirror and flashlight to look up through the thimble. Worse than I had hoped to find, but better than I expected. Couldn't see any damage, but got ahold of my landlord who informed me that the chimney passed when cleaned this fall, and that my sweep is a firemen and a certified chimney inspector, so it wasn't a marginal thing. And I don't run a fireplace through that flue, I use a VC Vigilant.

You have an entirely different situation with that 13" x 13" liner. That's Santa Claus size. Mine is only 7" x 7". I get way more velocity in my flue than you can possibly get with yours. Velocity is what brings the flues gases up and out before they can deposit on your liner walls. There is no way that you can burn your unit dampered down without lots of creosote building up, particularly at the beginning and end of a burn cycle. And using wet wood to boot? Not good, I fear. You will get a sluggish draft when the flue is cold and then too much once the stove gets really cranking (especially with that height) - a sure setup for an overfired stove (or a chimney fire if you have a large amount of creosote). At least that's they way I understand it.

Rule of thumb is not to go beyond three times the surface area of the outlet size. I believe your unit is rated for 8" round pipe. VC says not to go beyond 8" x 12" (96 sq.in.). 8" round pipe has a cross sectional area of about 50 sq.in. Your flue has 169 sq,in. That's more than the 3X rule by a healthy margin. I feel you simply need to get a liner, for safety reasons and to get what you want to get as far as burning goes. If you don't, please consider checking it every few weeks and cleaning it when you get more than 1/8" buildup.

Maybe someone more knowledgeable will chime in here. You have an unusual situation that calls for a lot more than I know.

 

[mnowaczyk]

This is probably a thread hijack... I should stop... but I try to get any assistance I can... and I will post what kind of mess I find in the chimney in a few days.

Thanks a ton for the info BattenKiller. I do really want to doa liner, but also want to assure it's not a huge project to go back to an open fireplace, especially thinking of resale value for the house. I know most folks say switch to a stove with a liner and never switch back, but as a novice burner, I'm not so shure I would be as interested in a house with a stove as a house with an open fireplace... open fireplace just seems to have more ambiance. So there's my reasoning for not wanting to destry the existing... basically perfect chimney.

I want to go with 8" liner (stove recommendation), but I will not be able to get an 8" oval to round adapter in through either the top or bottom. I can get round all the way down to just above the old 5" deep damper. Oval fits throught the damper, but not all the way up to the clay-lined portion (where it squeezes down just a bit in the brick before the straight-shot to the top in clay). So I'm bummed and looking for the ideal solution, and will listen to any suggestions.

Meanwhile... "every couple weeks" is a suggestion I've been searching for for quite a while. As soon as the weather breaks, I'm getting the chimney checked. I think that will be about 14 days of burning the stove:
-maybe 5 open fires
- fire up on the 27th... run 4 days till 31st.
- Fire back up on 4th and running since (5 days now).

I try to keep the stove as hot as possible until I might back down the intake before bed a bit to wake and find enough coals to start a fire back up. Pretty much a constant rise in temp from morning fire up to 400 stove temp (about an hour) up to a nice 600+ before bed. The evenings are nice and hot, and the heater has completely shut down by the heat of the day around 3 PM, and doens't have to run again until I'm asleep... probably 4-7 AM.


Getting back to your thread:

Why does webby3650 Say:
Have you had your flue inspected? If you found “puffy” creosote there is a good chance you have some busted tiles in there. There are some exceptions but if I find one I find the other.

Does "puffy" creosote mean there's been a chimney fire? Wouldn't most creosote burn off in a chimney fire? Or does puffy creosote attach to busted (unsmooth) clay?

I realize there are several different types of creosote, Shiny, Flakey, Sooty, but I'm not sure I know what "fluffy" is. Does that come only from a certain height in the chimney?

(Thanks for all the schooling!)

 

[Battenkiller]

DB, I'd start a new thread with all the info and what your needs are. I'm no expert in setup or chimney questions. That's all for the experts here AFAIC. I know what works for me, and my situation isn't ideal but I feel it works and is not dangerous. There are just too many variables for me to give you advice. If you have to check/clean your flue every other week something is seriously wrong. That's all I'm saying.

As far as the puffy creosote, it's the first time I've seen it. I don't usually inspect my flue but leave it up to my sweep who comes once a year in the fall. I heard it's not a good thing. I think it's expanded creosote from some sort of chimney fire. But the stuff I found was below my clean out door, so it must have fallen down during the last cleaning. Apparently my sweep didn't find anything wrong with the tiles or he would have told me about it. After looking at my chimney, I'm certain that it wasn't this burning season.

 

[mnowaczyk]

Thanks BattenKiller. I'm learning and you've helped me on a few threads now. I appreciate it.

Ironically I was out with some of my wife's friends last night, and as soon as we sat down, they started talking about how they almost burnt their house down with a chimney fire last week. They've apparently got a plain old no-afterburn wood stove in their basement with two 90 degree turns before it shooting up their 8" round terracotta chimney this is about a 150 year old house which probably always had a wood stove in this chimney. A sweep told my poor friends that the chimney swept with every cord of wood they burn... but do not mention the period, ar ANYTHING to them about the type of wood or burn temperatures. They never burn overnight, so they always kill the fire by closing the stove door, which is apparently drafty enough to let the fire burn down (as there is no official air intake). Apparently the horizontal portion of the stainless liner (leading to the chimney) just fills up with creosote the way they burn it... which apparently is not to hot beause the guy said he can only touch the stove for a split second without burning his hand... and he showed me how he'd put his full hand on the top of the stove for a second and pull it away. That sounds like a lot less than 400 degrees to me. I can't believe that now, the chimney sweep is only recommending they get the chimney swept every quarter... not mentioning anything about temps. I think he did describe the stages of creosote build up (which is more than I know), and the fact that their stove is probably only about 17% efficient... basically a wood stove that operates like an open fireplace. So we might rent a lift together and line both our chimneys one of these days.

Oh... I'll ask them if they have any pictures of the chimney. I know they had a camera run through it. Maybe that will help determine what your puffy creasote was.