wood stove install and flue pipes

Started by rebocardo, September 29, 2006, 04:58:13 PM

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rebocardo

Hi,

I finally have my wood stove almost installed and have a question about the flue pipe connections. I bought an engineered system from northern toolhttps://forestryforum.com/board/index.php?action=position"> Note:Please read the Forestry Forum's postion on this company to fit the stove (oulet) I bought from them.

Here is my setup, the stove is sitting on clay tiles, which are sitting on hardi board (1/2" thick cement). Directly under the stove and under the hardi board is thick aluminum flashing.

The stove will be sitting on regular brick (2") thick and over them will be a sheet of metal (to code for the NASD?) which would have been enough.

The area the stove is in with the tile is 6w x 10 feet.

The stove will be a min. of 40" from the wall and has nothing on either side of the stove for a min. of 40" all around.

I am using Duraplus (triple wall with ceramic blanket) for the through the wall and exterior chimney.

I am using Durablack (single wall) for the interior flue.

My question is most installations say to use only (2) 90 degree tees in an installation. No problem. But, they also say to angle the pipe 1/4" every foot.

I have a 36" section straight out of the top of the stove, a 90 degree and then 40" to the wall thimble. If I angle it up, it seems to leave a sort of a gap in the single wall pipe. Plus, it will not line up correctly with the triple wall stuff and where the triple wall mets the single wall, the fit is not tight, but loose anyways.

Is this okay? Or should I seal all the joints with a fire resisitant chalk? Or is that worse then having it a loose fit. I figure once it gets hot, the metal will expand anyways and the interior pipe (single wall) where it fits inside the stainless steel (triple wall) will expand to fit the gap?

I am going through a brick wall with stick frame on the inside, even though the kit is rated for where it is installed between the 16 o.c. studs, would be be worthless overkill to make it all brick inside the studs? I mean, brick transfers heat pretty good anyways so would it make any different?

So ... is the question is for those with stoves

1) Is the pipe fit along the run suppose to be kind of loose?

2) Where the single meets the triple is the gap something not to worry about?

3) Brick totally not needed around an engineered chimney and I am paranoid and it would not do any good anyways?


tcsmpsi

Not sure which stove you have ( not that it would matter a lot, I think, of your particular questions).

Generally speaking, you want to try to keep an 'upward thrust' of your hot air/smoke through your pipe/chimney system, as it will draw a bit better. Much of your smoke draw is determined by where and how your exit is placed.  One of the things with running internal wood fires, is that you need a little fresh air.  If there is a little bit of a gap (I know the amount and condition you are speaking of), any outside air you might possibly get from there will be more of a benefit than a detriment.

As far as any codes in that regard that you might have, I don't know. 

Now, as far as what I have done for the last 30 yrs or so of burning wood as primary heat, I would say that you have covered yourself quite well.   ;D

Your triple wall pipe has you covered as far as any heat exchange to combustible materials. 

I do always try to run mine a straight shot up through the roof, but have had to run it through a wall in the past.



\\\"In the end, it is a moral question as to whether man applies what he has learned or not.\\\" - C. Jung

Dan_Shade

any of you guys know the practical differences from the double walled stuff to the triple walled stuff?

Woodmizer LT40HDG25 / Stihl 066 alaskan
lots of dull bands and chains

There's a fine line between turning firewood into beautiful things and beautiful things into firewood.

breederman

I fill any gap where the stove pipe goes in the triple wall with stove cement,  otherwise when the chimney gets hot it draws room air through the crack cooling down the chimney and potentially causing creosote .
Together we got this !

mike_van

Pipes should all fit tight, even be sheetmetal screwed together, my 2 cents. The thimble into the wall must be a nice 90 where the regular pipe fits in, the only way to get some angle on that horizontal pipe would be to shorten the 36" piece, make the elbow on top of it less than 90, then use another elbow into the thimble, this one just enough angle to make it all fit. 2 45's flow better than a 90, here again, my opinion.
I was the smartest 16 year old I ever knew.

bitternut

I agree with mike about the two 45's instead of the 90. I don't like triple wall pipe on the outside. I would use double wall with 1" insulation . Triple wall will give you a cold chimney and lots of creostoe. Make sure that the upper vertical section is long enough to give you a good draft. That 4' horizontal section is going to reduce your draft considerably. To be honest with you I would move the stove a lot closer to the back wall. To do that you would need to use a metal heat shield at the back of your stove and also a metal heat shield on the pipe on the back side. I have that on my stove and it is within a foot of the back wall.

Wait a minute...........your in the south. What do you need a woodstove for? :D  :D

SwampDonkey

I don't know how they expect you to slant that last 40" pipe into the thimble. I've never seen it done on any flu here. It's usually straight and square into the thimble, but the pipe length is no more than 24 inches from the last elbow. Most of the time the stove sits to the left or right and not directly square in front of the flu. This way the pipe up from the stove hits an elbow, then that next section slants and then another elbow into the 24" section, then into the thimble. Something like this. But you can easily modify the setup for a stove sitting square in front of the flu with 45 deg elbows as suggested. Use a heat shield behind your stove and above the stove pipe.

"No amount of belief makes something a fact." James Randi

1 Thessalonians 5:21

2020 Polaris Ranger 570 to forward firewood, Husqvarna 555 XT Pro, Stihl FS560 clearing saw and continuously thinning my ground, on the side. Grow them trees. (((o)))

beenthere

I've an example of an angled stove pipe on my wood stove. I like the "less than 90° elbow" for better draft.
The first is from the wood boiler to the chimney.



The second shows the clay tile thimble I cemented into the clay tile chimney, and inserted a 6" pipe into that.



This is the original installation of 30 years ago. I never want to have to punch a hole into another clay chimney tile ever again. Once was enough.  :)
south central Wisconsin
It may be that my sole purpose in life is simply to serve as a warning to others

rebocardo

> What do you need a woodstove for?

To defeat my $300+ a month gas bill from last year. They did not bill me for three months because the company was switching hands (gas south to south gas) and when they sent the bill it was over $1100 just for the gas usage for only three months. Nice to tell you the rates increased after you already have used the material/gas. I was used to $30-$50 a month for the gas water heater and clothes dryer. Nearly had a stroke when I saw the bill :D

I completely ditched the gas in my house, that alone saved $130 a year just on the monthly service charge.

When I moved to the Atlanta GA area I thought "hot" and "peaches". Sometimes it gets down to 10 degrees here. Though it usually pops up to 40-50 degrees by three p.m.

Yea, I agree about the 45 degrees. Unfortunately, it does not seem they make the elbows (durablack - single wall) in anything other then 90 degrees and they only make the duraplus (triple wall) elbows in 30 degrees. I thought about trying to mix in another OEM 45 degree elbow  (I figured 6" is 6").  But, they give such dire warnings I got scared  ;)

My wall kit came with only a 9" extension for through the wall, had to buy buy another 12" triple wall for another $40. Spent more on materials then I did the stove  :o

The exterior chimney itself is going to be six feet tall and should put it as the highest point on the roof, if not above it. So, I am hoping that provides a good draft. I might run a grounding strap to it even though my house is surrounded by taller trees.

So, stove cement where the single mets the triple and leave the joints open on the single wall and I should be all set. I am going to screw all the joints together (impossible for the single to triple wall) once the set up is final.

> any of you guys know the practical differences from the double walled stuff to the triple walled stuff?

Yes, double wall (wall/insulation/wall) requires 18"+ clearance to anything combustible, so it can not be inserted through a stick built wall. If you do, you have to build an air box, etc. etc. Once done, you might as well just buy the triple wall stuff.

I had to retrofit a house once (working for a contractor) that had it going through a very tall ceiling and once you get the boxes built and everything inspected it just is not worth it. You have to insulate the screws from wood etc.

What triple wall (wall/insulation/wall/vented space/wall)does is surround double wall with an air pocket and a way to vent the heat between the 2nd and 3rd wall to the outside chimney to prevent build up of heat within the pipe.

Triple wall is rated 2100 degrees for an hour or something such as that. So, unless you botched the installation or ran a coal fire, you would have a tough time burning your house down. Which is what I worry about, botching the install since it is my first time.

So, triple wall installs were ever you can cut out a 14.50x14.50 hole. Which is the clearance between two studs on a normal 16 oc 2x4 wall.   

breederman

  we have the triple walled chimney going up inside the house.  It runs through the corner of bedroom closets. I didn't frame it in the closets for a long time and you could always hold you hand on it.  Never had a creosote problem, in fact I don't even own a brush for it.
Together we got this !

SwampDonkey

I recommend brushing the flu at least once a year and the pipes from the stove at least once a month or every other month if your not using it contiunously. Not brushing a flu is just waiting for an accident. You do know that you'll get more buildup from starting up the fire than having a continual burn?
"No amount of belief makes something a fact." James Randi

1 Thessalonians 5:21

2020 Polaris Ranger 570 to forward firewood, Husqvarna 555 XT Pro, Stihl FS560 clearing saw and continuously thinning my ground, on the side. Grow them trees. (((o)))

breederman

I check it a couple times a year.  Never had more than a little dust in it. It is our only source of heat. Just leave the door open for a few minutes every few days to heat her up good and it will clean itself!
Together we got this !

SwampDonkey

I've seen the creasote balloon up in the intense heat (outside flu) and plug the flu and fill the house with smoke to using that method. Happened to my uncle last winter. He has a selkirk flu.
"No amount of belief makes something a fact." James Randi

1 Thessalonians 5:21

2020 Polaris Ranger 570 to forward firewood, Husqvarna 555 XT Pro, Stihl FS560 clearing saw and continuously thinning my ground, on the side. Grow them trees. (((o)))

beenthere

south central Wisconsin
It may be that my sole purpose in life is simply to serve as a warning to others

SwampDonkey

Yes, when that creosote starts cooking on the walls of the flu it can bubble or 'balloon up' and then harden to block the passage of smoke and gas up the flu. So, where does it go, but back down and into the basement, then up to the upper floors of the house. What a nightmare.  ::) Inspect and clean the flu annually.
"No amount of belief makes something a fact." James Randi

1 Thessalonians 5:21

2020 Polaris Ranger 570 to forward firewood, Husqvarna 555 XT Pro, Stihl FS560 clearing saw and continuously thinning my ground, on the side. Grow them trees. (((o)))