Wood stove Insulated Stove Pipe

I need some help from any of you guys heating with wood. I installed a wood stove almost twenty years ago in my place, burn about 12 face cords a year. I used the double wall insulated 8 inch pipe. It runs straight up from the wood stove through the ceiling, through an upstairs closet, and out the roof. I used all the proper flanges where the pipe goes through the ceiling and roof. I noticed while in the upstairs closet yesterday that the pipe was too hot to hold your hand on for than a couple of seconds. Don't know if its old age or what, but I can't remember if thats the way its always been or not. The outside of the pipe looks as good as the day I installed it, I clean the inside twice a year and that looks good too. My question is , can the insulation in the pipe deteriorate without any signs? Any of you guys want to grab hold of your chimney pipe and tell me how long you can hold on for? Thanks in advance Dave

I can put my hand on the insulated pipe and hold it indefinately. Using a laser thermometer the stove and regular pipe are 800 to 1000 degrees. The insulated pipe measures room temperature. I suspect you have a problem.

Rocky in MO

I suggest that you take out the double wall pipe and install triple wall pipe. I've used it for nearly thirty years and have never had a problem.

Not a good time of the year to have to make chimmny repairs . My guess would be that the inside wall has a burnout spot in it . For a quick repair this winter they can slide a single wall 6 inch down inside your 8 inch to finish up the winter then take it down after winter is over .

I hope there are/were no clothes hanging in that closet.
Insulated or not the outside pipe will get very warm if it's "insulated" by clothing, drapes etc. Even if just in a closet with still air due to door being closed.
Kind of a tough call unless the pipe is visually inspected on the inside.
Being 20 years old the stack owes you nothing and very well could be corroded through.
Time to play it safe and not burn your house/self down by not burning any more wood.
I'm going to pass on some sage advice from jdemaris.Purchase your smoke stack in Canada. The price is the same but the specs are much higher rated.

Sounds to me like a burnout somewhere on the inside pipe that's eroded the insulating layer. The outside shouldn't get that hot. I wouldn't trust it.

I do my heating with wood. I have double insulated 6 in. stainless steel pipe. It is filled with something I can not see, as both ends are sealed. The pipe fits together with a slight turn, and a ss clamp goes around the joint. If I put my hand on my pipe I can not keep if on for more than a couple seconds, the pipe is very hot. I think the instructions require at least 12 inches clearance from combustable surfaces. My stove gets the wall so hot I can't tuch is also. My wall is sheet rock, 2 inches cement, and red paver bricks. I should have left a air space between the sheet rock and brick. Since I didn't do that I keep a piece of ss sheet between my wall and stove. I installed my stove pipe almost 35 years ago have a 90 into my garage and another 90 up through the celilig.I can see all my pipe this way, is why I did it. I check the pipe inside about every 2 years so far so good. What you are feeling may be normal, but I would find the manufactur and contact them.Stan

I used to sell this stuff 30 years ago Selkirk Metalbestos. double wall insulated pipe, stainless on the inside and outside, Just looked at their website, and it looks like only the outside is stainless now. But they do have different standards for Canada and the USA. I think double wall insulated makes a better chimney because it works on the principle of keeping the smoke warm til it gets out the top resulting in less cresote formation while Triple wall tries to cool the smoke to keep the outside temp of the chimney from getting to hot. The one in my house, you could easily keep your hands on the outside of the pipe, like someone said, room temp. I wouldn't use yours til I found out and fixed whatever is makeing it hot to the touch.

Try this forum it is kinda like hear. A bunch of smart well seasoned wood burners and different sights for pellet stoves and wood furnaces if you do not find a good answer here.

North east puller
wood burning forum

It takes a chimney fire to reach 1000 degrees.

I can assure you there is no chimney fire. I can't guarantee the accuracy of the thermometer as this is the only way I have to point and shoot different parts of the stove. The insulated glass reads considerably less than when opening the door and shooting inside at the fire. The top of the stove measures less than the first 1 foot of pipe which is un-insulated. At about 3 feet off the stove the pipe switches to the insulated pipe and goes all the way through the ceiling and above the roof peak. I monitor these temps regularly and that was the purpose of buying the laser thermometer. I don't make up this stuff, just merely report what my stove measures.

Rocky in MO

It is in the 20S outside and my Metalbestos 8feet from the stove is cool to the touch. My chimney is 20+years old. Newer chimney's have a different kind of filler between the stainless pipes I think.Don't know how the newer ones transfer heat.

I don't know a whole lot about those things, but I'm pretty sure that it's not normal for the outer pipe to be hot like that.
We changed ours about 2 years ago as the inside pipe was burnt through in several places. We were lucky enough to notice that when cleaning the pipe.
It only takes a day or so to install a new chimney. How long to build a new house?

It may be OK 90% of the time for you like this, but there's always that extra cold night that you pile just a bit more into the stove....
Those fires get rolling so fast that there ins't much that can be done with them when they get going good either.
Have an experienced person look at yours tomorrow before you or the house become a statistic.

Rod

Mine uses an eight inch chimney also straight up(only way to go). It is stainless inside and 2" of spun ceramic insulation and then outer pipe. You can put a torch to spun ceramic and it will not burn. Outside of pipe is barely warm to touch and on the roof the snow barely melts around it. Being straight up , I let the fire howl up it at start up and have never had to clean it. All it has in it is a light feathery sort of soot that carries itself out with a short open door blast once in a while. Forget the double or triple wall un-insulated stuff.This chimney has been in for 19 yrs now. I don't load up full with green wood and let it simmer either. Let your stove burn hot or not at all. It's that "in between" simmering that gets dangerous and plugs up chimneys.

We had a Metalbestos stainless steel chimney for our Earth Stove when we lived in a mobile home. The Metalbestos pipe came right down to the top of the stove and then went straight up through the roof. I installed it myself, but got permits and had it inspected. The setup was specially engineered for mobile home use and drew combustion air from under the mobile home. It worked great, and our electric furnace seldom ever came on.

But we used it for a long time and over the years, we had some very hot fires in the stove. It developed a crack in the stovetop and a crack in the back plate. So when we sold the mobile home, I decided not to sell the stove and chimney with it, just for safety and liability concerns.

The chimney came apart fairly easily, even though the sections had been assembled about 20 years before. The top 5 sections of chimney were in great shape, with almost no buildup inside and no problem areas. Unfortunately the section of chimney closest to the stove had the inner liner severely eroded, with many small holes penetrating to the insulation.

I remembered that the chimney was usually too hot to leave my hand touching it for any length of time on that section of chimney nearest to the stove top, but closer to the ceiling, it was much cooler. I always thought it was just radiant heating from the stove top, but after taking the chimney apart, I wonder if I had many chimney fires in that lowest section.

I intend to use the good sections of chimney in my barn when I get it built, and will probably use that same stove after I weld up the cracks. It never leaked smoke through the cracks, but rather probably sucked some combustion air through them.

If I was going to have a Metalbestos type chimney in my house, I would either run it through an area where it was exposed and visible, or else I would run it through a chase made of sheet metal or drywall. I would worry about running such a chimney through a closet unprotected, as I believe that the chimney might sometimes get hot enough to ignite items like clothing if they touched the outside of the chimney. But I am pretty cautious. If I remember correctly, the Metalbestos chimney was rated for 1" clearance to wood framing. I added metal flashing around the chimney where it went through the mobile home roof, just in case the ratings were a little optimistic. That part of the installation worked perfectly all those years.

Can the outside of a double wall, insulated stainless steel chimney get dangerously hot? Yes they can get pretty hot under certain conditions and I think it is a good idea to consider this when installing them and when using them. On the other hand, my Metalbestos chimney never had a creosote problem that required manual cleaning, unlike the triple wall chimneys that people I know have used. The Metalbestos chimney system is lots more expensive than the triple wall type, but in my opinion, it is worth every bit more. Good luck, and be safe!

It takes a stem thermometer inside the pipe to get a true reading.Surface temp is less.Above 500 degrees is risky.Metal workers use a temp stik that changes color at a predetermined temp.

Clearance to unprotected wood is 36 inches.Single wall stove pipe is 18 inches.A metal sheet must be spaced out 1 inch plus air gap at the bottom.It does no good to lay metal directly on wood.Wood that has been overheated for long periods ignites at a lower temp.I spent 35 years on the fire dept and have lived in wood heated houses for 70 years.Some stoves have reduced clearance.

Your thermometer is suspect...