chimney placement on the roofline

[morpho]

Okay, what I want and what I think I know to be the smart thing are often different.

"The spot" for my wood stove is on the south exterior wall, and this puts the chimney exiting on the bottom of the roofline...on the negative pressure side no less. Now if I move the stove 7 feet north in the house it will exit close-ish to the peak. (small house)

My question is...how much does it really matter if the chimney is down the slope or at the top if you keep the stack tall?

Roof is 7/12....so my best guess is I would need 6 feet-ish of chimney after it exits the roof.

 

[begreen]

If it is ok for stove placement I would opt for the second location. The more chimney that can stay inside the better. There will be less snow load and it will stay a bit warmer. Try to avoid coming up directly under the ridgeline.

 

[morpho]

Its a flat ceiling so there isn't any more stovepipe in the conditioned space...regardless of location...but certainly more in the attic if I go more central...Maybe a happy medium is to offset the chimney in the attic.
My best guess is that it would only require a few more feet of chimney, this would put it exiting closer to the ridge AND I would get to put the stove in the place I want it.
More money...poof! .....up in smoke...I knew I should have gone to med school instead of getting my PhD in "homeless underwater basket weaving"

 

[morpho]

Sorry....Hi Begreen...thanks for your input.
Yes...snow is an issue as it's a metal roof....AMAZING snow slides I tell you!

 

[morpho]

Why is nothing ever even remotely smooth and simple?

So in mucking around with a tape measure and crawling around the attic then reading the height suggestions from several chimney manufacturers.
I have bad, worse or even worse options.

1. If I run it straight up from down low on the roofline...I am looking at a stack about 8 feet tall once it leaves the roof.

2. If I put a 30 degree offset in the attic it only moves it about 2.6 feet further up the slope and I have a stack about 6 feet tall.

3. I move the stove further into the house and the stack drops to about 4.5 feet tall, but I have nowhere to put a couch and my wife is mad at me.

Why is life so hard!?

Any suggestions anyone?
(about the chimney....not life)

Thanks

 

[meathead]

I would go with an 8' straight shot stack properly braced back to the roof so it can handle the snow, and sit on a warm couch with a happy wife. If all other walls are out, and there is no other possible furniture location, that gets my vote.

 

[begreen]

We rearranged our entire living room floorplan when I removed the fireplace and created a hearth for the stove in a new location. At first it took some getting used to, but now it seems great. If you opt for the 8ft stack outdoors it will still work. Brace it at the 5 ft level and add a cricket uphill of the chimney flashing if the snow load is great.

 

[morpho]

hahahaha...Meathead...that is sage advice. A happy wife is all that matters in the end.

Begreen... hmmm No matter what I do I can't find a place for the couch. The couch would have to sit in the middle of the room and it's not a very big room, so it would be "awkward". Sounds like I should build an addition already!


Question:

So, as far as I can tell, there really isn't a huge difference in the chimney low on the roofline and the dreaded and much maligned out the wall installation.
Anything I can do to get the chimney to work as efficiently as possible given the limitations I have?

 

[begreen]

Actually there is quite a difference. An out the wall installation introduces two 90 deg turns which slows down draft so that more chimney is needed. It has a greater exposure to the cold and it usually costs more. It also doesn't look as nice IMO.

 

[morpho]

Ya...those 90's probably slow things down a bit.

I did the actual measurements last night and the final height from the roof will be 7', 10" to get me two feet above the ridge. Thats going to look so dumb! Oh well, I will console myself beside the stove this winter.
The total run of chimney and connector comes to 14'; only one foot off Morsø's recommended minimum!

Any idea why I can have 90's or 45's in the connector....or even a 90 in the chimney for an out the wall installation, but limited to a max of 30˚ in the attic?

 

[webby3650]

90's, 45's, and T's are acceptable in a chimney system only because they are accessible. A traditional chimney brush won't go through more than a 30 degree offset.

This is the flashing you want to use, they also make a snow wedge.(broken link removed to http://www.icc-rsf.com/main.php?t=chem_produits&i=95&l=en)

 

[begreen]

An 8 ft stack outside is not that bad, but with only 14' total you don't want to introduce any more resistance via elbows. According to Morso:
"We recommend the length of the chimney system should be at least 16 feet (not required) above the stove in normal domestic situations, measured from the flue collar to the top of the chimney."

 

[morpho]

Webby, Ya...that old access issue. I could put clean outs in the attic...I'm up there all the time making sure nothing is leaking anyway (paranoia)
Hey! and you are a rock star for the preemptive flashing link. I was going to use the Masterflash silicone boot, but this might be a better option. Thanks.

Begreen, "8 ft stack outside is not that bad"...I'm 5'5"...EVERYTHING taller than 5' 6" looks really, really tall! hahahaha...
Should I be concerned that I am falling short of the 16 feet? (thanks for the correction)

 

[webby3650]

Those silicone boots are crap! That excel flashing is the way to go for sure. It comes with good instructions too.

 

[morpho]

My local Hardware store is even a dealer! Never seen them on the racks, but I will order one up tomorrow. Thanks again.

 

[webby3650]

My local Hardware store is even a dealer! Never seen them on the racks, but I will order one up tomorrow. Thanks again.

Check out their snow wedge too. Snow will put the hurts on the flashing and the storm collar when its low on the roof like that. Also, screw the pipe to the flashing with short sheet metal screws. It'll give it a little added support down low and prevents the pipe from twisting below the roof when you take the cap off.

 

[morpho]

Funny, I was just looking at that on the website.
Begreen mentioned it as well. I have never actually seen one in use, but I have seen several chimneys taken out by snow...soooooo.

Thanks for the tips

 

[begreen]

I'm not sure how well this stove draws. You are one of the first to report owning one. I do know the Morso 2110 is a fairly easy breathing stove. A few years back I helped install one in a yurt and it only has a 12 ft chimney. Not ideal, but it worked. Going straight up will help. I'm not keen on the idea of a cleanout in the attic. Not even sure that is legal. You might be better doing bottom up cleaning with a SootEater if that is possible. Is it easy to remove the baffle in this stove?

 

[morpho]

Ya not even remotely legal I'm sure...but all the fun stuff isn't any more.
It was just a thought anyway...like I need any more complication around this place!
I'm offgrid, so I am responsible for everything that happens in this house to make it livable..right down to the DIY composting toilet.

Ahh yurts...they are pretty cool...I will take my solid walls though. I don't have to follow the caribou herds, so mobility isn't much of a concern!

That was actually another question I had regarding clean out. Is it normal to just remove the baffle and run the brush up from there, or does a telescopic stove pipe make it "easier" to detach...collapse and run the brush up? (if that is even something that is done)
The baffle seems easy enough to remove...I haven't mucked with it yet though. Seems to me I simply tip the sides down and then remove the baffle.

 

[webby3650]

Even if the stove has a removable baffle, you want a slip section in the connector pipe. It makes the installation so much nicer! When it comes to cleaning, there is no "normal". Every setup is different, you just do whatever is needed to get a broom through it.

 

[morpho]

Man...you guy's have saved me a whack of ground work! Thanks.