The Forestry Forum

General Forestry => Firewood and Wood Heating => Topic started by: Kelvin on November 15, 2008, 07:56:55 AM

Title: question on woodburning stove chimney, can i use single wall up the outside?
Post by: Kelvin on November 15, 2008, 07:56:55 AM
Howdy,
I've been helping my brother try install a used wood furnace cheaply.  I assumed the easiest thing to do would be to simply do what i've seen done all over the countryside, put a single wall, black pipe chimney up the outside of the house for less than $100 vs. stainless double wall for $750-$1200  When we went to the store to buy the stuff the guys scared us about doing this.  I assume that with stand offs we could keep the chimney 18" away from the house (code?) and we are using an old piece of triple wall through the basement window.  Is this a really bad idea?  Would house insurance people not cover this really?  I know that a brand new car is better than an old one, and more money usually gets you better things, but when all is said and done the reason we are doing this is b/c he doesn't have any money to heat his house.  He wants to try out the wood thing.  I've told him that stainless will last forever and be the best investment, but he wants to see if he has the time and energy to make it work for a couple of years.  Thoughts?
Kelvin
Title: Re: question on woodburning stove chimney, can i use single wall up the outside?
Post by: Gary_C on November 15, 2008, 08:50:23 AM
Not a good idea.

First it will draw poorly and backdraft into the stove. Problem is it will cool the flue gasses too much and they will not rise.

Second it will radiate enough heat at the bottom to burn the siding on the house.

And finally building codes usually require a Class A triple wall chimney for wood stoves.
Title: Re: question on woodburning stove chimney, can i use single wall up the outside?
Post by: zopi on November 15, 2008, 08:56:02 AM
Well...Fire is one thing I take no chances on...been through one house fire and that is enough..And if you've ever seen a flue fire you'll appreciate the reasoning behind double wall..

IMO the insurance companies will hose you for whatever they can, whenever they can get away with it..tried it with our house fire until I offered to feed the adjuster his desk planner...

Having said all that...well maintained single wall has worked for a couple centuries now, all over the world...it's what's going in my workshop, but not my home.
Title: Re: question on woodburning stove chimney, can i use single wall up the outside?
Post by: Reddog on November 15, 2008, 08:56:34 AM
Kelvin,
I won't cover the right or wrong of the code part.
But here are the real world problems I have had with single wall on the ext wall of the building.
It does not stay hot, so the gases condeses on the inside of the pipe and causes it to rot out within a year or two.
Also because it does not stay hot, it seems to be hard to get a good draft pulling the smoke out.
If we were going single wall like on the barn, we would use well casing.

Just my .02
Title: Re: question on woodburning stove chimney, can i use single wall up the outside?
Post by: beenthere on November 15, 2008, 10:37:39 AM
Thank the guy at the store for giving you the good information.  :) :)
Title: Re: question on woodburning stove chimney, can i use single wall up the outside?
Post by: SwampDonkey on November 15, 2008, 10:38:34 AM
I'd have trouble sleeping. I don't know why.  :-\
Title: Re: question on woodburning stove chimney, can i use single wall up the outside?
Post by: StorminN on November 15, 2008, 12:47:14 PM
Try to find the insulated pipe used... I've seen it at the local used building materials place here for about $25 a stick for 6"... it's worth it.

-N.
Title: Re: question on woodburning stove chimney, can i use single wall up the outside?
Post by: J_T on November 15, 2008, 01:12:18 PM
Yep tripple wall .I feel his pain i'm in the same boat  :'( Tryed that other smoke dector goes off at one  and you up with the doors and windows open no fun  ;D Every thing been posted in right I know the hard way .Since I never give up I may rig a blower on the outside pipe . Did that once but it got to run all time  ???
Title: Re: question on woodburning stove chimney, can i use single wall up the outside?
Post by: bull on November 15, 2008, 01:30:28 PM
build a stone chimney---- not sure on the hight you need but clay liners are cheap and a few bags of mortar and your time you could build a reasonable single flue chimney for cheap money
Title: Re: question on woodburning stove chimney, can i use single wall up the outside?
Post by: J_T on November 15, 2008, 01:50:49 PM
Mine gotta be 24 foot tall an not a stone in 50 mile  :'( :'(
Title: Re: question on woodburning stove chimney, can i use single wall up the outside?
Post by: bull on November 15, 2008, 01:54:05 PM
sorry, I have plenty you can come pick all you want.......
Title: Re: question on woodburning stove chimney, can i use single wall up the outside?
Post by: cheyenne on November 15, 2008, 02:11:04 PM
Since the price of oil is plummeting & he's not sure about the time & energy he will have to expend & the cost of doing it safely he would be farther ahead not doing either! or run the  piping up the existing chimney either way there's no easy or cheap answer. The main concern is safety & peace of mind. But no matter what I would go over that used stove with a fine tooth comb.....Cheyenne