OK, Here we are heading into July. About three years ago I installed a small air tight wood stove in my garage. The stove heats the garage well but the draft at times could be improved. I heat with seasoned red oak and a bit of maple. What the problem is that the pipe is double, wall but outside the pipe is simply warm to the touch and there is my problem. Can anyone point me in the direction of something to insulate the stove pipe outside the garage? My stove pipe is well above the required height past the peak of my roof. I do not have the resources for "triple wall". All I am looking for is some sort of heat proof insulation that I can wrap around the pipe (6inch) to help keep the pipe hot and hopefully this will improve the draft.
Stove Pipe Insulation
- Thread starter Kenskip1
- Start date
Hearth dot com is a resource for wood stoves and chimney setups as GJ is for gear heads. I’d swing over to that forum to get some pro tips, many industry pros reside over there and can let you know if what you are looking to do is possible.
jack stand
Well-known member
Being a garage, I doubt that you would have it "too tight" for make up air. But that could contribute to your problem.
Do you have a thermometer on the flue pipe above the stove?
Do you have a thermometer on the flue pipe above the stove?
Yes I do. It varies with the air control setting. Anywhere from 300 up to or around 475. I have reason to suspect that the stove itself may have a built in fault. The stove is virtually air tight. It has insulation along with fire brick and this keeps the heat inside the stove. However,, this has it's faults. A cooling of the stove pipe for one. What I am looking for is simply something to wrap around the pipe on the outside of the pipe helping the pipe stay hot and hopefully increasing the draft. Thanks for the reply, Ken
zak77
Well-known member
So is the entire length of stove pipe double wall? Especially on the exterior of the garage?
It is all double wall all the way to the cap. I am thinking about insulation that is used in engine compartments. Like keeping the heat from the engine or headers from migrating into the cab of trucks/high performance applications. What wood be ideal is insulation for 6 inch steam pipes. However, not within my budget.
zak77
Well-known member
I'd think you need to cover that insulation with something otherwise it'll get wet and be useless and more harmful than helpful when it does. I honestly dont think that's your problem and isnt going to help much at all. When spring time rolls around and the day temps get into the 50/60's my stove has a little more trouble creating a draft but never to the point where it's a real issue. Just need to crack the door/vents a little more for a little more time to get things up to temp. Do you have creosote buildup problems? That is the real definite way to know if you have a draft problem or running to cold.
Zak77 As to the creosote in three years I have cleaned the pipe once, and it needed it. As to opening the door a bit yes this does help but as soon as I shut the door the outside pipe is hot but cools off within 30 minutes or so. If I want a rip snortin fire then all is well. The pipe outside his hot, and the garage will be warm shortly. One thing I forgot to mention is that it takes close to an hour to get the stove hot. With the firebrick and insulation I guess that I should expect this. Otherwise the stove itself is tolerable.
metlmunchr
Well-known member
- Joined
- Sep 10, 2011
- Messages
- 1,281
Molded fiberglass pipe insulation has a max working temperature of 850°F. As others have said, I doubt insulating the exterior of double wall pipe will make any noticeable difference in draft.
rlitman
Well-known member
Sounds to me like your stack isn't tall enough.
jack stand
Well-known member
I can't think of an effective insulation (on a budget) that would survive very long outside, but I'm not a specialist in insulation or chimney dynamics. I'm wondering if a bag or two of rockwool (available in various thickness un faced and in sheets) wrapped in a "skin" made from a larger size single wall chimney pipe would be a reasonable experiment on any lower portion of your pipe that you could "wrap" without breaking your neck?
Just now the thought of wet insulation all summer long might not be healthy for either layer. (rust)
Be patient and watch c/l for some SS class A insulated pipe.
Just now the thought of wet insulation all summer long might not be healthy for either layer. (rust)
Be patient and watch c/l for some SS class A insulated pipe.
Nice video, but I quit watching when you went political, but it might have been better to show a pic of the chimney. Over 25 years I represented Selkirk and Dura-vent in the New England States. You have grossly misapplied the products you did buy. Double wall pipe is the best INTERIOR vent connector. It is absolutely not approved for use as a chimney and by the time you buy all the material to try to make it what you think it should be you will be into the cost of the proper Class A chimney. Should there ever be a fire your insurance agent will simply shake his head no.
Jackfre. Thank you for your comment. However you stated that double wall pipe is not approved as a chimney. Approved buy whom? I took pictures and showed them to my insurance agent. His words were your all set. The double wall pipe goes through a window and then outside then up about 9 feet. As seen in the video the wall is all brick. The chimney does not go through the roof but is on the outside of it. Thank you for your comment, KenView attachment 1483090View attachment 1483095
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American Locomotive
Well-known member
Ignoring the random metal zip-tied to the chimney and the interesting methods and materials used to secure the chimney to your house and support it - it's way too short.
Generally "they" say about 10 feet minimum of height above the surface of the fire for acceptable draft, but most recommend around 15 or more. Elbows also hurt draft, so you realistically probably only have 7-8 "feet" worth of draft. You likely need to extend that chimney at least another 3-4 feet to get effective draft.
Generally "they" say about 10 feet minimum of height above the surface of the fire for acceptable draft, but most recommend around 15 or more. Elbows also hurt draft, so you realistically probably only have 7-8 "feet" worth of draft. You likely need to extend that chimney at least another 3-4 feet to get effective draft.
kelpaso1
MEMBER EMERITUS
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That's an incredible hackjob install. Great way to burn your house down, and you even submitted it to your insurance!
Go do a little research here:
www.northlineexpress.com
Double wall stovepipe is for interior use to the thimble (through wall or ideally ceiling) then you use double or triple wall chimney pipe.
The thimble will space the pipe appropriately away from all combustible materials.
The chimney then must go 3' above anything within 10’ horizontally. You also have 2 90's I there, so you need to account for the bends and increase the flue length to makeup the draft.
Go do a little research here:
Why Buy Chimney Pipe From Us
Why buy your chimney pipe, stove pipe, pellet vent pipe or chimney liner from NorthlineExpress? We have experts available trained to help guide you through the installation. We also have the largest in-stock selection you'll find and at reasonable prices. Check us out and you'll find...
www.northlineexpress.com
Double wall stovepipe is for interior use to the thimble (through wall or ideally ceiling) then you use double or triple wall chimney pipe.
The thimble will space the pipe appropriately away from all combustible materials.
The chimney then must go 3' above anything within 10’ horizontally. You also have 2 90's I there, so you need to account for the bends and increase the flue length to makeup the draft.
dfiler2
Well-known member
For a wood stove you need insulated stove pipe, double wall pipe is used in applications where the inner pipe is for exhaust and the outside pipe is combustion air, make sure you have the correct pipe for a wood stove, Class A. The two 90's could be causing some of your issue and I think adding a 4' section to the top or changing the two 90's to two 45's would help a lot. I don't think insulating the outside would do what you want.
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Well, thanks for all the comments. I have been working with wood stoves since the 70's Yes this is not a perfect system however, being on a very limited income I have to make do with what I can lay my hands on. As mentioned I grew up with Vermont castings ,the Defiant, Vigilant, and the Intrepid. And BTW, there are many more chimney systems locally that are truly amazing structures made of less quality material than what I have. Thanks for the comments and wisdom. In my own defense I live on SSDI. I get around using crutches.
American Locomotive
Well-known member
It's understandable that money can be tight. At the very minimum you will need to extend the chimney by another 3-4 feet to get adequate draft. I'd probably go at least 5 feet more to be on the safe side.
Sometimes it can be better to save up a little longer and do it "correctly" to avoid issues. Triple-wall DuraVent pipe isn't THAT expensive if you stick with galvanized instead of stainless. Plus if you hunt around, you can usually find a good deal for chimney pipe on Craigslist or Facebook Market Place for people decommissioning old woodstoves.
Sometimes it can be better to save up a little longer and do it "correctly" to avoid issues. Triple-wall DuraVent pipe isn't THAT expensive if you stick with galvanized instead of stainless. Plus if you hunt around, you can usually find a good deal for chimney pipe on Craigslist or Facebook Market Place for people decommissioning old woodstoves.
OK, So what is better? Double wall or insulated stove pipe? I understand the concept of the double wall however the idea that the insulated pipe has a 1/4 air gap also makes sense also. What one would you use? Also I will extend the pipe a minimum of three feet. Thanks for your help. Ken
jack stand
Well-known member
Ken I think that your double wall pipe is to slightly reduce required clearance to a combustible surface.
I too was surprised how short your "stack" is. The rule of thumb (code) that a masonry contractor friend told me was
2' ABOVE anything 10' away horizontally. I would add the longest single length of pipe available, I believe that's about 6'. It will need to be secured properly and in the wind may cause your lower a rather flimsy (to be polite) looking "set up" problems supporting the additional pipe.
I too was surprised how short your "stack" is. The rule of thumb (code) that a masonry contractor friend told me was
2' ABOVE anything 10' away horizontally. I would add the longest single length of pipe available, I believe that's about 6'. It will need to be secured properly and in the wind may cause your lower a rather flimsy (to be polite) looking "set up" problems supporting the additional pipe.
kelpaso1
MEMBER EMERITUS
.........
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danski0224
Well-known member
If you are using Type B vent, and if it is outside and not in an enclosure, then there is your problem.
Type B vent is only good for 600 degrees (IIRC, not an exact number) and the interior is aluminum.
I would be quite surprised if the stove manufacturer actually approves the use of Type B vent.
Class A fabricated chimney pipe or triple wall pipe for wood burning fireplaces has a stainless steel inner liner.
The Class A chimney typically has a flanged connection and V shaped drawbands for assembly. There is a ceramic fiber insulation between the two pipes. Triple wall snaps together (does not come apart) and there is an air gap between the pipes. The Class A stuff is quite heavy, and may need to be enclosed in a chase rather than being left outside in the open. Expensive, too.
Proper draft is a small number measured in inches of water gauge.
Your exterior installation probably has enough draft, but it is cooling off too much.
Type B vent is only good for 600 degrees (IIRC, not an exact number) and the interior is aluminum.
I would be quite surprised if the stove manufacturer actually approves the use of Type B vent.
Class A fabricated chimney pipe or triple wall pipe for wood burning fireplaces has a stainless steel inner liner.
The Class A chimney typically has a flanged connection and V shaped drawbands for assembly. There is a ceramic fiber insulation between the two pipes. Triple wall snaps together (does not come apart) and there is an air gap between the pipes. The Class A stuff is quite heavy, and may need to be enclosed in a chase rather than being left outside in the open. Expensive, too.
Proper draft is a small number measured in inches of water gauge.
Your exterior installation probably has enough draft, but it is cooling off too much.
Be offended, but take a step back and think about this setup. Don't let it kill you.
Every winter around here someone burns a house down with a setup like this, with very similar reasoning for why.
What happens when you fall asleep in front of that, the wall catches and then you wake up to the roof on fire? Can you get out quick enough?
In your case this doesn't appear to be primary heat for your house, so why risk it?
American Locomotive
Well-known member
The double wall stuff is mainly meant for indoor use to stop your stack from charring things inside your house. Once the pipe goes outside or passes into an unheated area of your house - it generally needs to go to triple-wall insulated chimney pipe. The triple wall insulated chimney pipe helps keep the flue gasses hot, which improves draft. It also helps prevent creosote and other combustion products from building up on the chimney walls.
You can probably make the double-wall stuff you have now work, but your stack will need to be much higher, and you will likely run into issues with creosote and soot build up. If money is truly very tight - extend the pipe so it's well above your garage roof, and you will probably get the draft you need. You might want to consider installing a "T" for easier clean out instead of an elbow.
If you can put away $50-60/month, that would probably be enough to purchase enough of the cheaper galvanized duravent triple wall pipe to make a proper chimney by the time winter rolls around.
danski0224
Well-known member
Not only all of this, but then there are people offering advice or suggestions that are just as bad, or worse.
Stuff like mixing different classifications of vent piping. Or external insulation on Type B vent pipe.
The OP needs to follow the manufacturer installation instructions and use UL listed materials and methods.
Type B double wall pipe is listed for use in an attic or a chase.
Triple wall vent is specific to the manufactured appliance that uses it, like a factory built wood burning fireplace (usually made of metal with a refractory lining). It is an engineered system. One cannot use Type B vent or Class A fuel burning chimney pipe on a metal box wood burning fireplace insert designed to use triple wall pipe.
I'd bet that if single wall pipe is allowed on your stove, it is intended to be used for just a few feet to tie into a masonry chimney (this would absolutely be detailed in the installation instructions). There are factory built Class A chimneys for stuff like commercial kitchen exhaust, boilers and other fuel burning appliances (ie: wood stove).
Draft readings and the use of a barometric damper or other means of draft control are likely covered in the installation/operation instructions. It isn't simply add vertical pipe until it's high enough.
For a correct draft the piping should only go straight up.
danski0224
Well-known member
Offsets are allowed.
Again, detailed in the manufacturer installation instructions.
A lot of this stuff, like vent tables, is available online, for free, at the respective manufacturer website. No need for anyone to get wrong info from here and follow it.
Again, detailed in the manufacturer installation instructions.
A lot of this stuff, like vent tables, is available online, for free, at the respective manufacturer website. No need for anyone to get wrong info from here and follow it.
I'll post this again, there seems to be a few people here who could benefit.
This takes the guesswork out of everything
www.northlineexpress.com
This takes the guesswork out of everything
Why Buy Chimney Pipe From Us
Why buy your chimney pipe, stove pipe, pellet vent pipe or chimney liner from NorthlineExpress? We have experts available trained to help guide you through the installation. We also have the largest in-stock selection you'll find and at reasonable prices. Check us out and you'll find...
www.northlineexpress.com
Just for some clarification. B-vent is for non-condensing GAS fired appliances ONLY. It is good to about 600*F. I do not recall the exact number. All Fuel or Type A chimney was regulated by UL103 up until the early 80’s. 103 had a 1700*f standard. It was found that there were to many structure/life losses due to fires at the 1700* limit. UL103HT was instituted with a 2100*f limit and that remains the approval rating for todays all-fuel chimney. The 1700* pipe is still the standard for oil fired chimney, but is difficult to find as most distributors will stock only the 103HT. Oil installs are plummeting and the 103 pipe will become even more of a challenge. 103HT chimney is available in both triple wall and double wall configurations. Dura-vents Dura-Plus is an excellent triple wall design given its ventilated starter section. It is not preferred however due to its larger diameter. It could not fit in a 16” framing without headering the ceiling/rafters. The pack chimneys from Selkirk and Dura-vent rule the roost due to the smaller diameter. The 103HT pipe requires a 2” clearance to combustibles. Termination clearances are 3’ above anything within 10’. They are minimums and overhanging trees and other obstructions may require more. You are always better to run the pipe up through the structure to conserve the temp in the pipe to promote good draft. Having a poorly insulated product will facilitate creosote production. A chimney which has seen a chimney fire should be replaced. The extreme temps inside the flue will frequently cause the pipe to expand so greatly that the inner liner will buckle. The double wall pipe used as the Vent Connector only are DVL and DS from Dura-vent and Selkirk respectively. They are stainless lined and you can use 45’s, 90’s and tees. This is unlike any 103HT pipe which cannot exceed more than 30* from vertical. The only 103HT fittings available are the thru-the wall Tees and 15 & 30* fittings. Many connect the 15’s & 30’s to make 45’s but it is verboten. On their web sites, both Selkirk and Dura-vent offer excellent work sheets detailing about every manner of installation you can come up with…with the possible exception of “through the window.” They call out the part number and location of every component. I did a lot of venting and combustion air training with the Wood Heat Assoc and Chimney Sweep Guild and the stories are chilling. To the OP, I am sorry to be a hard-***, and appreciate your situation, but I’ve spent to much time in my 6 New England State territory with the Fire Dept/ Building Dept on structure fires to have any patience. It is playing with fire and it shows no mercy if it is let loose
If these comments offend, then the last thing you want to do is to post the pictures/video over on Hearth.com. They take a dim view of hack chimney jobs*. Expense and/or cost is always the excuse for not doing it right coupled with some form of "it's worked so far" attitude mixed in.
* I'm speaking in generalities here since I cannot see any chimney pics or videos. I see the "watching the fire" video, but that tells me nothing. Post #13 pics don't load for me.
FTG, Well here's a couple pictures. My inventory of materials is as follows, 12 foot of 6 inch double wall pipe, 2 ,90 degree 6 inch connectors,1 cap. I had some flashing that is going through the window. I am well over 12 inches from the brick wall and the stove has a heat shield between the stove and the wall. I have a 10 foot pressure treated post supporting the outside structure. The only structure anywhere near the stove is the window. Yes I do intend to increase the vertical length of the stove pipe buy 3 or 4 foot when the resources allow.
In my own defense I use what I am able to afford. As mentioned I am on SSDI and my resources are strictly limited. I do not or will not put a hole in my roof. As to the double wall and the insulated pipe I have intentions of replacing the double wall with the insulated pipe for the vertical assent. Hopefully this will keep the insipid comments to a minimum. Oh yea two more minor items to add to the shopping list, one stove and a damper. Thank you for your concern,,, Ken
![20210706_154847[1].jpg](https://www.garagejournal.com/forum/data/attachments/1330/1330182-f2a8195d7fd524f522257b4fb4d1abcc.jpg "20210706_154847[1].jpg")
![20210706_154912[1].jpg](https://www.garagejournal.com/forum/data/attachments/1330/1330183-9cd380551982a67a4f4b10df06dfd1f8.jpg "20210706_154912[1].jpg")
In my own defense I use what I am able to afford. As mentioned I am on SSDI and my resources are strictly limited. I do not or will not put a hole in my roof. As to the double wall and the insulated pipe I have intentions of replacing the double wall with the insulated pipe for the vertical assent. Hopefully this will keep the insipid comments to a minimum. Oh yea two more minor items to add to the shopping list, one stove and a damper. Thank you for your concern,,, Ken
danski0224
Well-known member
That looks like plain old single wall pipe to me. I certainly don't see any locking devices. And the crimp is "backwards".
Unless that wood post is petrified, it's combustible and in contact with what appears to be single wall pipe.
In my experience, people claiming to have "limited resources" still have cable TV and a fat cellular plan...
Unless that wood post is petrified, it's combustible and in contact with what appears to be single wall pipe.
In my experience, people claiming to have "limited resources" still have cable TV and a fat cellular plan...
Sir, the pipe IS Double Wall. And the crimp is backwards you say? Please explain this. The pipe is sitting on a brick between the pipe and the post. Your experience's? Sir I get around with crutches, and have stage two prostate cancer. So don't tell me about your experience's. I am 65 years old a disabled vet with cancer and my future is uncertain at this time. I have limited strength in my right hand. So if I want to go an watch my satellite sports program I will. So get off my back.
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Jackfre,I have had the stove going on three years. I cleaned the stove pipe the first time last fall. The pipe had small bits and pieces of creosote but nothing worth worrying about. The stove has secondary combustion and when it starts the flames literally roll onto the glass. Actually it is a bit scary. So much so that I emailed the manufacture. The sent me a message that this is perfectly normal. The stove is burning the creosote was basically there reply. Do I trust it? Yes I do. I close the damper and leave the air intake open (throttle) just a crack. Come morning the wood has burnt down to coals and my garage is around 60 degrease. My garage is 25 foot buy 20 foot approximately. Anyway thank you for your wisdom. Ken