Dream chimney ?

[berlin]

i've never reinforced a masonry chimney; nor have i heard of anyone having to do so. i've seen chimneys that had been attempted to be reinforced and this can cause problems, during periods of high heat (around christmas during large fireplace fires etc.) the rebar expands thus cracking the top portion of the chimney among other problems. when i said firebrick liner i mean using actual "high duty" firebrick to build the flue inside the chimney; it's more than acceptable to code, it's done routinely for industrial and certain commercial chimneys, and it'l make the longest lasting most durable chimney possible

 

[Nicholas]

The reinforcing of a chimney was covered in BOCA and now the new IRC (R1003.3.1)
There is a reason I build my own chimney's and do not hire them out to "Real" masons.
90% of "real" masons I have hired are drunks that would not know a code if it hit them up side the head,
They do not use refractory on flue tile joints, the fill type N and trash tight against the flue tile, they do not use rebar, etc,
they just build them the way the guy who built them for 50 years showed em how.
Sad but true, no offense to any "real" masons doing it right.

Nick

 

[dvellone]

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

Yes. !/2 " of mineral wool would be more than adequate to create a slip plane allowing expansion. Take a look at ceramic blanket insulation as a nice performing alternative to mineral wool. Another option for you is to construct the chimney with hollow core block. You can reinforce and pour the corners. The application of brick to the exterior goes up real quick if you're not used to laying brick without a backing wall of some sort. Did you check your local codes for reinforcement of an interior chimney? Some areas with no seismic activity consider tying to joists as appropriate reinforcing.

 

[MovingOffGrid]

speaking from personal experience, having a thermal mass of a brick or stone chimney in the center of your home is such a tremendous feeling. This is how they heat near the artic in Scandinavia and they've got it down to a fine science. You're not wasting flue heat, you're storing much of it, to release gently into your home over hours and hours. Very pleasant heat and definitely adds to the value of a well built home.

I was fortunate to find an excellent European mason when I built my house in the late 80's. My 30' straight up brick chimney and 6X10 tile liner has stood up fine with 22 years of burning and has been fully inspected. Built like a tank. It drafts well, especially in the cold, and makes heating an entire 2500 sq ft two story home possible with only a large wood stove on the lower floor. If I ever get any cracks I can always slide a liner down it (heaven forbid), but so far, it's been one of the best investments I made in this home.

Thermal Mass Thermal Mass Thermal mass ;-)

having said that, I have heard that some building codes now 'require' ss pipe even though a retired fire chief told me recently that they see more fires in SS than in Tile/Masonry. and so goes 'progress' in North America! Better double check with your local building codes to be sure.

 

[dvellone]

speaking from personal experience, having a thermal mass of a brick or stone chimney in the center of your home is such a tremendous feeling. This is how they heat near the artic in Scandinavia and they've got it down to a fine science. You're not wasting flue heat, you're storing much of it, to release gently into your home over hours and hours. Very pleasant heat and definitely adds to the value of a well built home.

I was fortunate to find an excellent European mason when I built my house in the late 80's. My 30' straight up brick chimney and 6X10 tile liner has stood up fine with 22 years of burning and has been fully inspected. Built like a tank. It drafts well, especially in the cold, and makes heating an entire 2500 sq ft two story home possible with only a large wood stove on the lower floor. If I ever get any cracks I can always slide a liner down it (heaven forbid), but so far, it's been one of the best investments I made in this home.

Thermal Mass Thermal Mass Thermal mass ;-)

having said that, I have heard that some building codes now 'require' ss pipe even though a retired fire chief told me recently that they see more fires in SS than in Tile/Masonry. and so goes 'progress' in North America! Better double check with your local building codes to be sure.

I'm on board with your feeling. The point about thermal mass and Scandinavian technologies is especially relevant. The Scandinavian masonry heaters are an excellent example of efficient wood heating technology. Refractory materials are integral to their function - insulated steel would be antithetical to their performance. Now, masonry venting doesn't play the same role in a free standing wood stove, and although a steel chimney is wonderfully affordable, safe and user-friendly venting option, the Masonry heaters illustrate that the only way you can use "suck" to describe ceramic clay tiles is when describing what the draft does when you get the fire going - It sucks...upward and outward.

 

[ccwhite]

I'll throw my $.02 in here. I've not seen a steel chimney last 20 years but commonly see masonry chimney that have been standing and in use for 100 years. As one person said in a worst case scenario you could slide a ss chimney liner in if you ever had a problem (or rather your great grandson can once it's his house). Go with the masonry. Just my $.02

 

[snowtime]

I have a number of stainless chimneys the oldest being 28 years. Its in top shape and I am of the opinion that masonry chimneys are more expensive and at least as susceptible to damage if not more so. Stainless is easier to repair or replace. Most chimneys are damaged by operator abuse [chimney fire ] or maintenance neglect. Maybe most of the masonry chimneys i have seen that have damage are due to poor installation but that just goes to show how difficult it is to get anything done right these days.

 

[dvellone]

I have a number of stainless chimneys the oldest being 28 years. Its in top shape and I am of the opinion that masonry chimneys are more expensive and at least as susceptible to damage if not more so. Stainless is easier to repair or replace. Most chimneys are damaged by operator abuse [chimney fire ] or maintenance neglect. Maybe most of the masonry chimneys i have seen that have damage are due to poor installation but that just goes to show how difficult it is to get anything done right these days.

Right! But it's also true that most things of great design and value don't come easy. I think that ss chimneys are a wonder of engineering providing those of us with woodburning appliances incredible versatility, affordability, and most importantly reliability and safety. They're readily available, easy to install and, if you were moving you could dismantle the whole system and take it with you to your new home. That said, I'm not saying that one form of chimney is necessarily superior to the other. In terms of longevity ss may last a lifetime - that very well may be the fact. I don't know as they haven't been around that long. And it may not even matter if they last a lifetime as they are many dollars less than masonry and can easily, and with affordability, be replaced. I do know from my professional experience that there are many masonry chimneys that were designed and constructed correctly that have more than outlasted the lifetimes of their owners as they should be expected to based on their cost. What I'm saying is simply that a properly designed and constructed masonry chimney is in no way inferior to an ss chimney in terms of performance. With all due respect to those that argue otherwise, I think that opinions to the contrary may be based more upon improperly designed and/or constructed chimneys and less upon correct masonry chimney design and construction. I see many more examples of the former than the latter myself. Each design fits it's own niche - If you need a reliable, safe affordable and simple system, ss is the way to go. If you want or need the mass that masonry provides or desire the architectural compliment, masonry might fit your need. I know folks who didn't have as much money as they did do-it-yourself motivation who put up their own simple tile lined block chimneys in their homes and saved a bundle over using ss. If you hired a legitimate builder to construct the same simple thing you'd be out several thousand minimum. I've built chimneys in architecturally beautiful homes that cost well into the five figure range. These folks want masonry as a compliment or center piece and are willing to pay for it. An ss chimney would do the same thing in respect to functionality but didn't appeal to their design taste. I have an ss chimney here in my cabin venting my castine and I love it. When we build our main house I'll put in a large masonry mass centered in the layout with the woodstove venting on one side, a fireplace on another side, and both oven and grill on the kitchen side. It'll be a great functional design that only masonry can afford and rest assured, the tiles won't crack ;-)

 

[kfhines]

Nick,

Look into a product by ISOKERN (DM80 has two flues) you have to call them on the DM80 because it doesn't show up on their web site. The DM series flue system is a double wall zero clearance chimney. Made in Denmark with mined pumice. The last I knew they were building a plant in North Carolina. I built one in my new addition some 32' from the basement thru the roof and I'm not a mason. You will need to shim them now and again to keep it plumb. All the parts are tongue and groove making it almost fool proof. They are not cheep, but I would do it again. I have only burned a bout 1 1/2 cord in the basement stove so far. It's worth a look any way.

kfhines