Wood Stove chimney

[gman1_2]

I am new to the site and have found a bunch of good advice here. I need some advice on putting up a chimney. I have been around wood stoves and wood heaters in the past but never had one of my own and definitely never installed a chimney. I have a US Building made of heavy gauge, galvalume steel. I am going to include some pics. I need advice on running the chimney through the wall. Need advice on how big to cut the hole for the 6" chimney pipe to go through without affecting the galvalume steel (worried about fumes from the galvalume steel if it gets to hot). Any advice and help is greatly appriciated

 

[Highbeam]

First advice is don't run it through the wall. For several reasons, a roof exit is superior. Run straight from the stove collar vertical and through the roof. Cheaper, more heat, better draft, simpler install, easier cleaning, etc. Also, it is best to penetrate near the ridgeline of the roof.

Your metal has a deep profile so there will be some custom flashing.

With standard wood structures, the class A stainless steel chimney pipe must be 2" away from the wood. May as well stick to that so that you can be certain that the galvanized metal won't get too hot and also to be sure that the chimney pipe has room to move. OD of the standard 6" class A chimney pipe is actually closer to 8" so a 10" diamter penetration is sufficient and will be covered by standard flashing.

Figure out how you're going to flash the hole first. Your building style might mean that you need to consult the manufacturer of the building for suggestions on how to flash it.

 

[Shop Specialties]

Straight up is the only way to go. Use a Dektite rubber boot to seal it.

 

[DPelletier]

ok;

straight up is better for the reasons mentioned but it is a royal pain to seal corrigated metal roofs. If you do it, get as close to the ridge as possible so water/snow can't build up.

Galvalume or galvanized metals are considered non combustible and zero clearance is required. 20ga galv is used as a 90 min. fire separation according to our local code and fire doors and fire rated access doors are also constructed of galvanized steel. There is no way that you are going to get anything other than temporary oils from the manufacturing process burning off.

Melting point of Galvalume coating is 600 degrees Celcius and galvanized coating is 650 degrees Celcius. Outside temperature of an A vent should be less than 100 degrees C.
A vents are sometimes referred to as "zero clearance" chimneys and in some instances can have zero clearance to combustables...galvanized is considered non-combustable.


Dave

 

[Shop Specialties]

That is why you use a Dektite rubber and it will seal up just fine. I have been installing stovepipe for 21 years and have zero leaks using Dektites on every type of roof.

 

[Charles (in GA)]

You are using a Class A chimney system I hope? Such as Simpson Dura Tech.

I have class A with my used oil heater and you can put your hand on the outside of the pipe when the heater has been running for a while. only 80 degrees or so surface temp.

The main issue is going thru the corrugations. You need to exit thru a raised area to minimize leakage. Buy a calking tube or two of GE Silicone II in Aluminum color. You will need it to seal around the pipe.

Charles

 

[Charles (in GA)]

That is why you use a Dektite rubber and it will seal up just fine. I have been installing stovepipe for 21 years and have zero leaks using Dektites on every type of roof.

Go to Amazon and search for "dektite" you get all kinds of hits. Never seen this before, but looks like the cats meow. Red high temp would be nice. Roof probably gets hotter in the summer from the sun than it does from the heat of the chimney.

You will need to make something to support the chimney inside, as you don't want it to protrude inside that much, use single wall flue pipe up to the transition. Chimney will need to extend well above the roof to have enough length for a good draft. Probably will need guy wires or support braces.

Charles

 

[Highbeam]

Code requires that after the first peneteration, that class A is used. There is no regulation limiting the amount of class A that comes into the building. You can go right to the stove with it but I wouldn't do that since it is expensive compared to black pipe.

The normal methods of supporting the weight of the class A are either to attach it to the deck with a clamp and flange made for this or with a ceiling support box attached to framing beneath the roof.

Since your roof deck is the structure and since it is so corrugated you will need something pretty custom.

 

[aka Larry]

Damn I love this site! I learn abut new stuff all the time.

Dektite Installation Video

 

[pfarber]

I just pulled the trigger on one of those Dektite red jobs. Thanks! Now I have to find a storm support. I am not going to use a 'Class A' pipe... steel roofs don't need it, if I understand what I read.

 

[koditten]

If you don't use the class A, how do you keep the penatration seal from degrading from the extra heat from an uniulated stack? Will you have a potential leak problem in the future?

Many times I have seen the uniulated stacks get red hot as it exits the stove. Those decktites must be able to stand some serious temps. Just curious.

I was also under the impression that the insulated stack helped with draft. You want the smoke to be carried up the stack and not cool too fast. No?

 

[pfarber]

I don't think there is much of a chance for the pipe to get red hot 13 feet away.

For my specific install the pipe will be a straight up run.

The red flange material is good up to 450F continuous... That seems more likely.

 

[Charles (in GA)]

I just pulled the trigger on one of those Dektite red jobs. Thanks! Now I have to find a storm support. I am not going to use a 'Class A' pipe... steel roofs don't need it, if I understand what I read.

You need the class A because it is insulated, not to protect the building, but to keep the inside of the chimney hot so you have a good draft, and to keep it clean. A simple single wall chimney will soot and coke up from being cold and won't draft worth a flip. I don't know a darn thing about chimneys but I know this just from reading and researching the web while installing my used-oil fueled heater.

I was also under the impression that the insulated stack helped with draft. You want the smoke to be carried up the stack and not cool too fast. No?

Ding! Ding! Ding!...... we have a winner!!!!!!!!!!!!!!

Code requires that after the first peneteration, that class A is used. There is no regulation limiting the amount of class A that comes into the building. You can go right to the stove with it but I wouldn't do that since it is expensive compared to black pipe.

The normal methods of supporting the weight of the class A are either to attach it to the deck with a clamp and flange made for this or with a ceiling support box attached to framing beneath the roof.

Since your roof deck is the structure and since it is so corrugated you will need something pretty custom.

I agree. Might be worth bringing the chimney down inside somewhat to avoid having so much above the roof. You do want some stovepipe inside, helps radiate some of the heat, so its beneficial to the heating of the building. Just don't want so much that it cools the stack too much. Need that draft. You are correct, I suspect an angle iron frame attached to the building would work to support the chimney.

The OP might want to read up on these and other documents.

http://www.duravent.com/docs/product/BestPractices_Woodburning.pdf

Edit: Dura Tech Install guide link does not work, will try again.

http://www.duravent.com/docs/product/DuraTech_L820_2012-sept_w.pdf

Charles

 

[pfarber]

I'm not buying the premise that 3 feet of uninsulated stove pipe will cool the 400-600F gas to such a degree that there would be some sort of temperature inversion in the pipe causing draft issues.

Maybe on a 50-60ft pipe run, but most garages are single floor... at best 20 ft?

Of the little research I have done, most draft problems are:

To many bends
To small a pipe
Not high enough over the roof.

 

[Highbeam]

If you're just going to use a single wall culvert of some sort then why not buy some thickwalled pipe and weld it to the roof? A good weld so that it doesn't leak rainwater. Make sure it is pretty straight.

Your stack is short, you say 13 feet, which is less than required for most modern stoves. Your draft will **** and you'll need all the help you can get.

 

[aka Larry]

I'm not buying the premise that 3 feet of uninsulated stove pipe will cool the 400-600F gas to such a degree that there would be some sort of temperature inversion in the pipe causing draft issues.

Maybe on a 50-60ft pipe run, but most garages are single floor... at best 20 ft?

Of the little research I have done, most draft problems are:

To many bends
To small a pipe
Not high enough over the roof.

I'm planning a double-barrel heater for my shop so I've also been doing research and following this thread as well.

My neighbor has the same double barrel Vogelzane setup I'm planning to use and he echos the comment above regarding the length above the roof. He said when he first installed his, it smoked up the shop like a mofo, and couldn't get the fire to stay lit because of no draft. He extended the pipe about 3 feet above the roof peak and the problems weres solved.

Some other good info here.

 

[NUTTSGT]

That Dektite boot is pretty damn slick. If I had apole bldg, I think I would be using that.

 

[pfarber]

I have the USSteel (or whatever the non-Voelgang one is) and so far have done one burn to get the oil/paint burned off the drum.

It was outside and I had 3 2ft sections of black stove pipe. The only smoke was at start up and when the paint boiled off (man did that smoke!). With 6ft, the large bung open and the vent in the door open it was smokeless until I opened the door, then it lost the draft and some smoke came out the door.

It actually worked better with 6ft than with 4ft, and of the 4 logs I put in it I got over 3 hours of burn. There little ash.. maybe enough to fill the bottom of a 5 gallon bucket for about an inch.

I don't know how well that will translate when I put it into the garage, but unless I run into trouble I am not going to spend $100 on a Class-A pipe if I don't need to.

If I need to, I will.

 

[beerthanks]

Great idea with the stove. It looks like you have plenty of good advice with the chimney. What sort of stove are you putting in?

The area looks fairly big. Ive put in a stove recently in my kitchen, its a 4.5kw Irish made Hamco. Lovely classic/contemporary stove. Brings lots of enjoyment. Im considering putting one in my small garage.

 

[gman1_2]

Lots of good advice guys. Thanks to you all. I said wood stove to begin with but actually I will be installing a single barrel wood heater. Looks like I will be checking out the Dektite boot.

Lets me see if I have this right I need black pipe to the roof line then class A pipe to go through the hole to go out the roof and to extend at least 3 foot above the highest peak in the roof. Is this correct

Thanks
Greg

 

[Charles (in GA)]

Lots of good advice guys. Thanks to you all. I said wood stove to begin with but actually I will be installing a single barrel wood heater. Looks like I will be checking out the Dektite boot.

Lets me see if I have this right I need black pipe to the roof line then class A pipe to go through the hole to go out the roof and to extend at least 3 foot above the highest peak in the roof. Is this correct

Thanks
Greg

Even though this link is largely related to home fireplaces (or inserts) the basic ideas are the same for any wood burning stove or fireplace. Read this link, you need more chimney than 3 ft.

http://www.duravent.com/docs/product/BestPractices_Woodburning.pdf

 

[pfarber]

That duravent document was very insightful. But there are some caveats that are not addressed regarding a garage vs a house.

Houses are pretty much as air tight as possible. That's why the stack should be high as possible. But a garage will rarely be that air tight where the garage is, in essence, making a low pressure with respect to the chimney.

Secondly if you plumb in outside air, or have a drafty garage then it seems that most of the pressure issues are moot.

I plan on putting my short (13ft) singe wall (black pipe) chimney at the lowest point of the roof (about 2 ft from the eave) and I have absolutely no qualms about it, nor that it will not perform.

Just waiting on the Dektite flashing to arrive..

 

[cj7365]

I think a thread on your chimney/wood barrel fireplace install would be awesome

 

[Shop Specialties]

#1 - All fuel pipe is to be used to meet code even if you have a metal roof.
#2 - All fuel pipe will draft where as the single wall will be cold and you will have draft issues.

Selkirk Ultra Temp is the best pipe on the market. When you go through the roof use a Roof Support Package from Selkirk. It is a 18" piece of all fuel pipe with wings attached to it. Those wings screw down on top of the roof to easily support 5 foot of all fuel pipe on top.
I use the gray Dektites with Selkirk Ultra Temp with zero issues in 21 years.

 

[aka Larry]

Could you make your own 'Class A pipe"? NO, I don't mean one that meets 'code', I mean one less expensive that does the same thing.

Couldn't you use a 6" stove pipe inside a 8" one with insulation between, or just leave the air gap between the two to perform the same function?

 

[Charles (in GA)]

#1 - All fuel pipe is to be used to meet code even if you have a metal roof.
#2 - All fuel pipe will draft where as the single wall will be cold and you will have draft issues.

Selkirk Ultra Temp is the best pipe on the market. When you go through the roof use a Roof Support Package from Selkirk. It is a 18" piece of all fuel pipe with wings attached to it. Those wings screw down on top of the roof to easily support 5 foot of all fuel pipe on top.
I use the gray Dektites with Selkirk Ultra Temp with zero issues in 21 years.

selkirk manual and catalog for reference

http://www.northlineexpress.com/media/wysiwyg/pdf/metalbest-installation.pdf

http://www.northlineexpress.com/media/wysiwyg/pdf/metalbest-catalog.pdf

Duratech manual and catalog for reference

http://www.northlineexpress.com/media/wysiwyg/pdf/duratech58-installation-instructions.pdf

http://www.northlineexpress.com/media/wysiwyg/pdf/duratech_2011cat_web.pdf

Single wall stove pipe manual and catalog for reference

http://www.northlineexpress.com/media/wysiwyg/pdf/durablack-instructions.pdf

http://www.northlineexpress.com/media/wysiwyg/pdf/durablack_dvl_2011cat_web.pdf

 

[pfarber]

Your first assumption is that everyone must meet code. This is incorrect.

There are more 'improper' wood stove installations than 'proper' by several magnitudes... nothing bad is happening. Code is nothing more than protecting the insurance company and manufacturer from liability.

Any one with common sense (and I readily agree that common sense is nowhere near as common as it should be) means that you can install a stove and it will work fine for decades.

If you want a picture of my install... close your eyes, think of a black single wall stove pipe protruding 2 ft above a single 20gauge green corrugated galvamune roof. Then put a rain cap over it. In 20 years it will still look exactly like that.

 

[Shop Specialties]

Single wall pipe will not last nearly as long as all fuel pipe especially when exposed to the elements.

Meeting code will protect you in case a ' oh **** ' moment should ever come up.

 

[Shop Specialties]

Could you make your own 'Class A pipe"? NO, I don't mean one that meets 'code', I mean one less expensive that does the same thing.

Couldn't you use a 6" stove pipe inside a 8" one with insulation between, or just leave the air gap between the two to perform the same function?

No. Just use the correct pipe and be done and over with it.

 

[Highbeam]

Not following codes, and not getting permits, makes you responsible for your actions. You will be self insired if a fire burns down the shop and you will also be liable if anybody else or their stuff is lost in the fire.

At some point this risk is acceptable. A tin shed with no contents out in the woods where nobody but you knows about it or will be inside. Plan on removing the stove when you sell the place so that your liability won't extend to the new owner's desired uses. These things can come back years later to haunt you.

You can make this stove work in several non-compliant ways. Since the building is entirely non-combustible you will have hard time burning it down so a lot of the codes can be ignored from a safety standpoint but some of the shortcuts I see will lead to a lousy burning experience with smoke, creo, and water damage to the structure.

 

[pfarber]

If you wanted to take the time to put sand around the inner/outer tube that will work. Won't be the best use of your time but will get the same results. Will be ungodly heavy, and need tons of support, but will work. Remember sand is all they use for molds when casting steel... molten steel is a little hotter than your wood stove.

6in ID 'all fuel' pipe is like $100 at TSC.

If I had to penetrate a wooden structure then I would use it... no question. But we are talking about (and I have) a steel roof/garage.

Not really worried about steel catching fire. Remember: Common Sense.

 

[pfarber]

Not following codes, and not getting permits, makes you responsible for your actions. You will be self insired if a fire burns down the shop and you will also be liable if anybody else or their stuff is lost in the fire.

At some point this risk is acceptable. A tin shed with no contents out in the woods where nobody but you knows about it or will be inside. Plan on removing the stove when you sell the place so that your liability won't extend to the new owner's desired uses. These things can come back years later to haunt you.

You can make this stove work in several non-compliant ways. Since the building is entirely non-combustible you will have hard time burning it down so a lot of the codes can be ignored from a safety standpoint but some of the shortcuts I see will lead to a lousy burning experience with smoke, creo, and water damage to the structure.

I completely agree... best practices are there because they work and are proven methods. If we were talking wood structures than I would completely agree with insulated pipe.

But penetrating a galvamune (sp?) roof in a mostly empty steel garage? Low risk of fire, and the insulated stack gains little for the cost.

I will still disagree that the last 3 feet of stack are going to cause huge draft issues due to cooling. Most of your draft issues will come from poor placement of the pipe, to many bends or restrictions.

 

[gman1_2]

Thanks for all the replies. Lots of good information for me to use. Now I need to make my final plan of attack on this and start gathering parts.

 

[aka Larry]

Thanks for all the replies. Lots of good information for me to use. Now I need to make my final plan of attack on this and start gathering parts.

I've just ordered my double-barrel stove kit so please keep us updated on yours.

I've read that Class A pipe above the roof is the way to go, but damn that stuff ain't cheap! If I bought the amount needed per the basic rule, and used just regular stove pipe inside, the cost of the pipe would be double the cost of the stove!

My plan is to buy 16' of the 6" Duravent back stove pipe and go straight up through my all metal roof, seal at the penetration point with one of the Dextite seals and add a rain cap. If it doesn't work you can all say I told you so.

 

[gman1_2]

Thanks for all the replies this forum has great information in it. I got the barrel heater put together and put it out in the yard to burn a fire in it so the paint would burn off (for about 5 hours). That thing smoked like crazy for awhile.

Now I just have to get the heater located in the shop and start running stove pipe for it. I have to work the weekend so it will be next week sometime before I can get at it again.

Got a load of white oak firewood for free just had to split it up and the gentleman has more for me to came get maybe another load when he gets it cut.

Before everyone panics I did move the little propane torch in the last pic away from the heater and put it back in the shop out of harms way

 

[Tim The Tool Man]

I've read through this entire thread and if I am getting this correct the OP (or aka Larry) is leaning toward using only black stove pipe up through the roof. No trip. wall at all? Very bad idea. No, you probably will not have a fire hazard the first year or so, but after that??? Leaks? within a month for sure.

Couple things to consider. Black pipe rusts like crazy and 24 gauge after a year is maybe lost 1/3 to 1/2 half it's original thickness when heat, moister, and creosote have had their way with it. Especially if it is used outdoors. Within a year or two your pipes will wither away and leak at the roof line and/or become choked with creosote past the roof line because of the temp change.

Also the heat at the roof boot will render the boot and any sealant useless after just a few firings, again causing leaks.

Spend a few bucks, get a trip. wall through the roof kit and a few feet of piping for outside.

Also not mentioned in this thread is to consider putting the vent in an accessible location on the roof for the annual cleaning that you should be doing.

Making your own trip wall pipe? Can a person do it? yes. Should they? no.