Wood Stove Chimney Pipe Questions: Kind, max length?

Hello all,
Please let me say thanks for all the help I will more then likely get on here.

I'm installing my first wood burning stove. Yeaaaaaa!
I am going to install the stove into a two sided chimney and wanted to know what kind of chimney pipe I should use (single or double wall) and what are my limits?
Just wanting to know what my best options are.
I'll have a couple of elbows on top of the stove to make up for the exhaust offset but other then that my pipe will go straight up the existing chimney. I've removed all the clay flue material that was in there and have plenty of clearance for the chimney pipe. The distance from the top of the stove to the roof is 25 feet....is the length a problem and if it is what are my best options?

Thanks in advance.

Ed Pe : The very 1st thing I should tell you is one heating appliance per chimney, I could write thick book about the number of ways you can get in trouble with
trying to use the same chimney to run two heating appliances located on ether side of a common wall !

I believe that you are telling me that the original clay flue pipe lining was in bad shape and you had to remove it entirely and you now have a much larger
passage area up through and out of your chimney !

Assuming that your chimney is in good shape, an Ideal compromise between cost and safety will probably be single wall pipe, with a backfill around it of ether
perlite or vermiculite, and make a new cap covering the whole of the top of the brick chimney with your single wall pipe passing through a centered opening
and provide the whole thing with a metal cap.

I am sure that that will be much cheaper than installing double/triple, or insulated pipe, but you could check on that. Obviously for the amount of material you
need, you measure from the inside base of the chimney to the peak of the chimney !

Now, here it gets interesting, the chimney Should have been installed on the Lee or downwind side of your house, 2 things- On paper I can 'prove' that there
is a sweet spot just below the peak of the lee side of the roof where the chimney should end, Often because the prevailing winds did not always blow from the
same direction All heating season long, Most chimney builders would build the chimney to a height 4-5 feet over the peak of the roof !

Here my recommendation allows you some personal liberty, But you may find that '' The storm of the Century''* comes from a totally different direction and gives
you new problems, you Can try shorter, but be prepared to find you have to go above the roof line !

A late thought, your wood stove was made to use a certain sized stove pipe, with the extra room you have in your chimney it will be tempting to increase its size
for better draw, short answer don't if you go with a loose pack of perlite / vermiculite around your chimney you should be able to increase your chimneys size by
1'', any more and you will hurt your draft !

Working up on a ladder is scary fun, don't lean the ladder directly against the chimney and work safe with one or more helpers!

Hope this was timely and useful for the good of the craft ! Big AL

* " The storm of the Century'' seems to be coming through every 30 some years A.L.

Thanks so much for the reply......a little more info.

The chimney that I'm going to install the stove in has plenty of space on its sides at least 10 inches per side....I feel pretty good with that since I am redoing all of the chimney brick and refractory cement on it. Also I don't think I'm going to light it up like the fourth of July...planning to be a little conservative burning it really hot. If single wall pipe is okay to use for a 25 foot run with plenty of clearance around the pipe that would be more cost effective for me. My concern is with it being such a long run will I have problems with the draft and creosote build up? I do have a rather large addic and does get cold in there during winter days.

As far as the top of the chimney it does go past the peak of the roof 5 feet and don't see a problem with the pipe going through the top of it, as the chimney box is covered with only a sheet metal top.

Thoughts....suggestions?

Thanks again.

Ed Pe : You will need to remove that cap and lower each section down slowly securely screwing each section togather, the lengths will come in 30'' long and 60''
long sections. As long as you can seal off the top of your Chimney to keep the perlite or vermiculite dry, you should have no problems with the chimney cooling
down to much ! If you run your wood stove wide open for 20 minutes a day during your heating season and clean it heave someone clean it at the start of a
heating season (again more work on the roof !) Creosote should not be an issue !

You might want to take a look at our Rocket Mass Heater RMH section with this system you are assured all Creosote is always burned up and you cant have a
problem, no more climbing on the roof ! For the Good of the Crafts ! Big AL

I also want to install the chimney pipe. But the outer wall of the chimney gets cracked. Is it good to install without repairing it ?

Steve Reyes : It is possible that all your chimney needs is re-pointing, you want to find a local chimney sweep who can use a remote camera to look at
every thing on the inside, he will probably also be a mason or turn you overt one unfortunately this will not come cheap ! Big AL

To me this topic seems to jump around discussing several different things.
I am going to either install a Double wall insulated Stainless pipe as chimney or. A New Chimney. I am only going 24 inches about my peak. Not five feet.
To me, If your chimney liner is damaged. It is obvious that you need to tear it apart and redo it completely. Blocks and liner are installed together. The clay liner does not just slip out of it. If you have any questions about my personal Present and Current experience with my stove. PM me. or ask away. one thing that I will never do again. I will not use a 90. I will always use a Tee where it is possible.
I stay away from Horizontal pipes and I have a two story building. Chimney is aprox 30 feet from bottom to top.

The specifics from the New York State & International Building Code, chapter 10:

"R1001.6 Termination. Chimneys shall extend at least 2 feet higher than any point of the building within 10 feet, but shall not be less than 3 feet above the highest point where the chimney passes through the roof."

Sounds pretty reasonable to me.


If you have a metal chimney anchored with standoffs so that it passes right next to the peak of the roof, would it be within the letter to say it is within 10' but not passing through the roof?

Glenn H. : Just to be very clear- With a final Vertical Exterior Chimney, it makes good sense to place it close to the peak of the roof, otherwise you will end up
standing on a ladder above the ladders pivot point, (where it leans against the buildings roof at an angle) or against the stove pipe itself.

Besides these bad choices, there is standing on a pitched roof and working head high or higher to disassemble a section of stove pipe to allow inspection, none
of these appeals to me.

I think the Code is a good minimum. While on paper I can 'Prove' that there is an enhanced Venturi effect when the chimney is installed on the lee or downwind
side of the house just below the peak of the roof, I have seen very few locations where the wind Always blows from one direction only.

And I have seen many locations where Deep Crusty snow and ice loads on the roof can make a mockery out of the hopeful -

''2 feet higher than any point on the building within 10 feet''
especially on flat or shallow pitched roofs !

My best meant advice here is install the best pipe you can afford, and expect to need to go 4-5 feet over the peak of the roof. 2' over the peak will do for Most
everything but the ''Storm of the Century'' which seems to come more and more often.

Knowing that your to code stovepipe installation got you through the LAST 10 years is cold comfort when you cant get a good draw, or good heat during that
event.

For the Good of the Craft ! Big AL