Dream chimney ?

[Nicholas]

Soo,
Still bouncing this around,
I am putting in a double flue chimney (wood burner and Masonry heater or cook stove).
Material price is not a problem - I want the safest chimney, as usual I will be building myself.
This will be an interior chimney, with about 5-6' out of the roof.

If You could spec out the best chimney, what would it be?

rigid S.S. insulated in a Brick chimney ?
Flue tile in a brick chimney ?
some kind of poured in liner in a brick chimney?
free standing S.S.? (no masonry around it)

Things to consider:
The masonry around the Rigid double wall sounds safest ?
Cleaning - It is a 10/12 pitch roof, imposible to stand ontop of (or lean ladder against) 6' S.S. poking through the roof to clean.
Easy to lean a 6' ladder against the top side off a masonry chimney to clean
Design it to be cleaned from the bottom ????

Any thoughts or recomendations before I finalize plans for this years project ?

Thanks,
Nick

 

[Nicholas]

Maryland - not too cold

 

[Highbeam]

All steel. Brick chimneys have good aesthetics when they are new and if they are done well. Otherwise and over time, there's nothing superior about a masonry chimney. You say only 5-6 feet above the roof, so why can't you just stand on the roof and sweep it. That's way less than eye height when you stand above it.


Time to rig a safety loop to the ridge. 10/12 is not even a 45 degree slope. It's like standing on a kid's slide at the park.

 

[KarlP]

Mine would be a three flue 8x8 clay lined masonry center chimney. Thimbles on both of the outer liners in the basement for a wood & conventional furnace/boiler. Thimble in the center liner on the first floor for a wood stove. Cleanouts below each thimble that allow running an 8x8 brush up from the bottom.

 

[Nicholas]

HB,
brain freezing on the details of how to penetrate the roof (cathedral ceiling) with 3 S.S. chimney's.
I think for shure I would build a framed chase "on" the roof, to enclose and support the S.S. chimney's.
With a "roof cricket" on the high end, the tops should be about nose level when standing on the cricket.

Nick

 

[weatherguy]

Mine would be a three flue 8x8 clay lined masonry center chimney. Thimbles on both of the outer liners in the basement for a wood & conventional furnace/boiler. Thimble in the center liner on the first floor for a wood stove. Cleanouts below each thimble that allow running an 8x8 brush up from the bottom.

Sorry I cant help but I want to follow this thread because your doing almost exactly what I want to do in my next house that I build.
Good luck with your project and we expect to see some pics

 

[Highbeam]

All steel. Brick chimneys have good aesthetics when they are new and if they are done well. Otherwise and over time, there's nothing superior about a masonry chimney. You say only 5-6 feet above the roof, so why can't you just stand on the roof and sweep it. That's way less than eye height when you stand above it.


Time to rig a safety loop to the ridge. 10/12 is not even a 45 degree slope. It's like standing on a kid's slide at the park.

are u the genius that was purporting an older frostfree refrigerator's performance in the middle of winter?

I do own a frostfree fridge that is almond and it works dang fine all year round in my heated home. I don't think that makes me a genius though.

 

[Lumber-Jack]

I have a white frost-free fridge in my house, I'm just not sure it has anything to do with this thread though?

My dream chimney is pretty much what I have except I'm still working on the cleaning access aspect of it.
In building mine I had several prerequisites I wanted to meet; first of all it had to pass inspection. Then I wanted it to be easily inspect-able and serviceable over the entire span. I went with double wall up to the ceiling (could have gone with single clearances for my application but felt double wall was safer) and used insulated, double wall the rest of the way up through the attic and out the roof.
The last prerequisites is I wanted easy access to the top for cleaning. I also have that right now, but only because I have a temporary scaffold set up on my roof. I plan to mount some braces along the ridge for putting planks, and a permanent ladder on the back side of the roof to reach the peak.
My roof is a steep metal roof and the chimney comes out near the peak about 14 ft back from the gable, so there is no way I can reach it by leaning up a ladder.
I believe that one of the main reasons you hear of so many chimney fires out there is because it's hard for most people to check, or clean, their chimneys. Consequently if it's hard to do something you just don't do it. It's just human nature.
Make it easy to clean and inspect and you increase the safety factor by 10. (Results may vary per individual)
I'm not a fan of masonry chimneys, too many of them out there either don't work, and/or are unsafe, or they have had metal liners put in them to make them safe and function properly, proving that metal is the better way to go.

 

[denn]

I use round masonry liners with a mix of vermicalite and portland cement.
I'm thinking it's 9:1 mix, would have to look it up.
Remember smoke goes up in a spiral.

 

[SWNH]

I am putting in a double flue chimney (wood burner and Masonry heater or cook stove).
Material price is not a problem - I want the safest chimney, as usual I will be building myself.

Well, if material price is no object, how about lining it with space shuttle tile? That way you could have regular chimney fires to clean out the stack instead of sweeping it.



* Sorry, couldn't resist...

 

[berlin]

if money is no object, i would go with masonry chimneys with high-duty FIREBRICK liners w/ 1/8"max fireclay joints. many commercial (large and small) chimneys are built this way where durability is more important than keeping initial costs low.

 

[fraxinus]

Modern stainless steel "chimneys" may be fine, but they never look very good to my eye and they certainly don't have the several hundred year old track record of masonry ones. So, for what it is worth, and with no thought about expense, I'd go with a brick chimney (or brick where it shows inside and from the roof line up, concrete lifts elsewhere) with poured in place flues. Why poured in place instead of tile? Better draft because of its circular interior. No mortar joints. Much more resistant to cracking in the event of a chimney fire or shifting. Because the poured liner adheres to the brick and fills in any interior crevices, you'd have a structure that would probably last a millenium or two.

 

[Nicholas]

Are there any DIY poured in place liners ?
I have been in the structural concrete business for many years, so this would be a breeze.

1) are the poured in liners self insulating ?
2) can I use single wal S.S. as a flue form ?

Thanks,

Nick

 

[Nicholas]

Well I did some more research today.
none of the "well known" poured in place liner companies have anyone in Maryland.
I called around and found one outfit that does poured in place, they just use their own mix (bags of such and such), they did not give the warm fuzzy feeling.

So I am back to S.S. or regular old flue tile ( I can not find any info about firebrick flue tiles)

Nick

 

[fraxinus]

The only poured in place I'm really familiar with is Supaflu (www.supaflu.com) The mixture used is a proprietary formula developed in Britain in the late 70's/early 80's energy crunch. It contains vermiculite and Portland cement, but the other ingredients I don't know. It is self-insulating. The former used is flexible and inflatable. It's placed in the chimney, inflated and the mixture is poured around it. After 24 hours the former is deflated and removed. Perhaps your contacts in the concrete industry could lead to some do-it-yourself possibilities.

 

[Nicholas]

And the problem with a S.S. Flue in a brick Chimney is that the "brick chimney" has to be completely hollow
to run the flue down, there for it is not grouted with rebar, masonry chimney's MUST be renincorced.

Back to the drawing board.

Nick

 

[DAKSY]

You say you wanna be 5 - 6' out of the roof...
On a 10/12 pich you can't meet that requirement,
unless you're within 4 - 5 ' of the peak...
Otherwise it won't meet code...
Anywhere else on the roof you're gonna have
12' of chimney exposed from the higher side of
the roof penetration to the under side of the cap...

 

[dvellone]

I built chimneys for years for other folks and now, gearing up to build our dream home I will put in a masonry chimney.
Aesthetics are much more pleasing if that's a concern of yours. As far as performance goes nobody can tell you that a properly built and insulated interior masonry chimney won't perform as well if not better than steel. Insulated steel stays hot as long as the flue gases are hot. As soon as they cool so does the steel chimney - no mass. An interior insulated masonry chimney would retain heat more consistently through the burn cycle optimizing your draft performance. As far as longevity goes if that's a concern of yours, we've yet to see 100 year old steel chimneys and how the caustic nature of creosote affects them over the long haul. Sure we all see plenty of deteriorating masonry chimneys just like shoddy built homes, cars, and you name it, but of the quality built chimneys constructed by knowledgeable Masons- especially those built inside the home- there are plenty that have been in use for 100 years or more. Sound joints, and all. Do your research and you'll find mason standards and practices. In particular the astm masonry standards publication. You'll find a lot of differing opinions on masonry construction even among less informed "masons", but this is a technology that has been around for literally thousands of years and today's approved methods have been tried and tested for a long time. Forget the do-it-yourself manuals here and the easy to come by advice. Go right to the Standards and if you're doing it yourself research, research, research.

 

[oconnor]

If you are sold on brick with a liner inside, I'd use the Simpson Duraliner pre insulated as the flue liner - I'm not sure that clay products are up to the challenge of todays and tomorrows stoves.

Overall, I'd use Stainless prefab Chimney (freestanding SS). There are some reasonable looking brick-like products that could serve as a facia around the roof penetration where the stainless flues exit the roofline. The part I like about the stainless prefab is replacement later in life - all of the solutions will fail at some point in their service life, and it seems to me that the stainless prefab will be easiest to upgrade later, assuming you build the chase large enough. Also should be easier air seal around, so would make the house envelope easier to manage.

 

[Nicholas]

It will go through the roof about 4-5' from the peak.

Nick

You say you wanna be 5 - 6' out of the roof...
On a 10/12 pich you can't meet that requirement,
unless you're within 4 - 5 ' of the peak...
Otherwise it won't meet code...
Anywhere else on the roof you're gonna have
12' of chimney exposed from the higher side of
the roof penetration to the under side of the cap...

 

[Nicholas]

dvellone,
When you say an "insulated masonry chimney) what part is insulated.

Thanks,

Nick

 

[dvellone]

dvellone,
When you say an "insulated masonry chimney) what part is insulated.

Thanks,

Nick

The required airspace between the flue tiles and outer masonry unit is typically filled with a dry, pourable material such as vermiculite or perlite. You could also wrap the tiles with ceramic blanket insulation prior to setting them. This is a bit more costly but settling wouldn't be an issue and the r-value is a bit higher.

 

[Nicholas]

99% of "real" masons fill around the tile with type N and scrap, up tight to the tile, no wonder so many tiles crack.
I had thought about wrapping the flue tile in 1/2" mineral wool, before filling in the void between the flue and outer masonry (with mortor)
The reason I am filling the "void" between the tile and the outer masonry (brick), this is where I place the required 4-#4 rebars, if there is no CMU core around the tile.
Would that allow the tile to expand ?

Nick

 

[denn]

When You say “round masonry liners” , do you meen standard round flue tile ?
Verc-portland mix, is that poured around the liners?
................................
Round is the same material as the square liners. But are used for crocks, thimbles and come in a
verity of lengths up to 24" long. Because there not used in the same sales vol., they are more $$$$.

(broken link removed to http://www.superiorclay.com/flue-liners.php)

I won't call it poured.
You use a min. amount of water (dry)and place it.
Another way that I've tried is after I get above the crock, the next liner. I put 2" or so at the joint
with a lower ratio. Then pour ver. only above that, up to the next joint and compact it a little
so it doesn't settle and start over again.

 

[snowtime]

I have a different take. I built 2 log homes in cold country. The thing i found is you want to separate your heat sources. The masonry sounds good but they are only good in a set temp range meaning its very easy to over heat. The wood stove would be for augmenting the masonry or instead of during strange temp fluctuations. What I am getting at if you want flexibility in your heating system and want to heat 100% with wood than have at least 2 different sources at different ends of the house, one in the center and one at the kitchen works well also. As you are not in cold country maybe the aesthetics of the situation will outway the practicality.