I'm being told that a masonry chimney is required if I want to avoid really high insurance rates. I had planned to use triple wall but I now think that flue block with a tile liner inside is the way to go. Where can I find design ideas for this type of chimney? Here's my idea on supporting the chimney. I searched a little bit on the web but did not find any real detail on how to build this. Can the blocks set directly against the wall? How do I get thru' the wall and into the chimney? Do I need some sort of access to the inside of the chimney at the bottom? I already have a piece of triple wall going thru the wall at about 6' off of the floor that I'm using temporarily. Suggestions welcome.
Quinton
(https://forestryforum.com/gallery/albums/userpics/13195/chemney-1.JPG)
Someone on here recently suggested taking a look at the Rumford fireplace. I checked their web site (www.rumford.com) a couple days ago. They had a very informative article on building fireplaces and chimneys, it might be worth a look.
I would go masonry & flue tile top to bottom. Have a Cleanout at the bottom to shovel out the soot when you sweep it twice a year. Masonry will out last the pipe.imo. Keep that chimney as close to the peak as possible....less chance of leaks around the flashings & the more chimney inside the more heat for you and less weathering of the masonry.I would have the wood stove at GL to heat the floors of the first storey.
I would try to keep it close to the peak too,just because it's easier to get to,to clean it.We had a house built and I never gave it a thought until I went to clean the chimmey.We had a 3 flue chimmey built,oil,wood and fireplace.The way I had it set up in the basement was I wanted the oil funace on the front of the house.The oil flue is closest to the peak,than the firpalce,than the wood stove.That's a good 5 feet higher than the oil flue is.Too late now.Would of been real easy to switch everything around.Have a outdoor furnace now,but I had to deal with that for 6 years. Have your clean out door at least a foot of the floor or ground.Easy to clean out that way.I did have the hind sight to have that done.I would prefer brick when it comes through the roof too.Looks better and brick with last longer with the weather.Don't know how much freezing temps you get.Cider block will asborb some water if not sealed every so often.
I don't think you can install a masonry chimney without footings on the ground level and the chimney sitting directly on the footings. Just too much weight for any other support method.
Not that you could not have a structural engineer design a raised platform to elevate the base, but even then the thermal expansion of the steel support could cause problems with movement of the masonry part.
The way these insurance underwriters work now days, they will probably raise your rates anyway you install a wood stove.
Q, this is one I did this fall for my shop - It's about as simple as they get. 8" round fluetile, single row of brick, and filled with rubble type stuff between the two. The footing is 4 courses of cementblock, structure up, filled with cement, sitting on a 36x36 concrete slab 8" thick with rebar, 42" deep. Thats our frost code here. I can't imagine what it weighs, 22' tall, I sure wouldn't want it sitting on an 8" pipe though. My opinion, is masonry top to bottom, I don't think you'll find any building inspector that will aprove anything but. An architect or engineer could probably do something using large steel pipe, say 20", but by the time you pay someone like that, you may as well have just layed the brick or block. (https://forestryforum.com/gallery/albums/userpics/11530/chimney_donex.jpg)
Im w/ mike 4' footing and masonary all the way !!! about $900.00 in materials for a 32 footer.
I poured a base footing 6'x6'x18"and then a 4'x4'x4' foundation and then started the chimney block....
2 courses then a clean out... single flue pencil chimney....
I use 6" S.S. insulated. Anything else, in the north, will cool the smoke. I havn't every cleaned a chimny. My .02
> How do I get thru' the wall and into the chimney?
For my triple wall SS chimney I used a factory thimble kit.
I have done reconstruction on a house for a contractor and they (city code) made the home owner put in a fire barrier. Basically a 12" air space all around constructed of sheet metal that vents out. I think they are frowning on direct brick to wood contact because if the tile or motar falls out and if a crack opens directly into the house from the flue it can burn the house down and it is basically like a flash fire and the house gets engulfed within seconds from the attic.
They have a fire department code to mean a fire from a chimney that burns the whole house down. It is what the insurance department refers to for a claim. Forget the # at the moment. But, it gets referenced when doing a chimney inspection.
I agree with sharp edge. Put in a good class A triple wall stainless steel chimney. As long as you extend them up far enough, they are better all around than masonry chimneys. If the insurance company does not like it, find another insurance company.
Insurance hates wood burners. Years ago I had a wood burning stove in my garage ,the insurace agent had a cow. He wanted it removed . I did because I wasn't using it much any way. Fast farward a couple years , atree branch fell on my garage roof /sidewall . Agent comes out and looks it over and as we are walking between the house and garage he asks me if the garage is attached to the house? ????????????? I told him the obvious No . He then proceeds to tell me that I am not covered then. >:(
Needles to say he no longer is my agent.
Build it as you see fit aslong as it is up to the National Building Code for woodburning devices You should not have any problems.
8" clay thimble through the wall, I formed and poured the wall between the chimney and the stud wall. Then brick faced the inside wall 3" wide and 6 feet high... You will need a hearth 3' wide Plus the stove depth and 18 inches. the 18 inches is required between the stove and the masonry
Quinton, one problem that I've experienced with my house is that smoke and ash sometimes gets blown out of the fireplace and into the house.
I think that this is because the top of my chimney is a few feet lower than the ridge of the roof.
Below is a photo of my house. The chimney is located on the north side of the house (and north side of the roof ridgeline), and it's closer to the outer wall than the ridge. My roof ridge runs east/west, and in the photo below the fireplace is in the NE corner of the house. Although it's hard to tell due to the angle that the photo was taken from, the top of the chimney is about 3 - 4 feet below the top of the ridge.
I think that the problem is caused by breezes blowing from the south that flow up over the ridge and down into the chimney - forcing ash throughout the house (as well as smoke depending on the temp and wind force). Since most older houses all seem to have chimney's that extend above the roofline, I am surmising that you may want to be sure that your's extends a few feet above as well.
Regards, Scott
(https://forestryforum.com/gallery/albums/userpics/13296/House%20-%20front%20view2.jpg)
Scott is correct about the down draft thing. If I remember right, I think the chimney needs to be 2 ft higher than the highest roof surface within 10 ft. Even then I get an occasional down draft with my chimney.
thats all, sy
Here's a chimney design for ya- the old colonial house in CT that I grew up in had a twist in the chimney- it spiraled 90 degrees in the attic. On a really still night, you could make out a spiral in the smoke. Do you suppose there was a reason?
yes the flue needs to be 2 foot higher than any thing within 10 feet, however if it was my chimney and on the low side of a roof I would go even higher.
I had good results with the 2 wall insulated stainless pipe. It isn't cheap but works well, is UL listed and is engineered for small clearances to wood surfaces if you use their supports and pass throughs.
Wow! Pretty house Scott. I hadn't seen pics of it before.
Just a few notes to clarify my situation. The bottom of my cabin is completely open and the support pipe (I'll propably use a 12" pipe just because I have it) will set underneath of the porch. A 12" pipe (or an 8", for that matter)will easily carry the load of 20 blocks and flue linner. Pipe is very strong in compression as long as it is kept in column. I think if you compare the strength of pipe and cement blocks in compression you'll see what i mean. The chimney will set on the porch deck and it will be far easier(and cheaper) to fit the pipe in there than to build block all the way from the ground up thru' the deck. The chimney will go through the porch roof rather than an insulated interior roof so that makes cutting the hole and possible leaks around the block a little less problematic. I worry a little about sealing around a steel roof.
Thanks for the input everyone...keep it coming.
Quinton
Qweaver
I am guessing the stability of the chimney on the pipe isn't the compression forces, but more of the column stability at the interface of pipe to block. The 12" might handle that design problem, but the 8" might not. Would be good to know ahead of time.
EXACTLY what Beenthere said! :)
In order to make it work, you would have to do a three or four pipe supported platform that is several times larger then the footprint of the chimney.
The old one that was on my house had a smaller but large enough footing, but because it was a simple four block square per layer and was at the low side of the roof, it was very unstable even with the footer.
Being as tall as it was and having as much exposed as it did, I was able to simply push it over with little effort when I removed it.
I would NOT use the pipes for the base and I would NOT build a tall narrow one, but that's simply my 2 cents.
Quinton, if you use the pipe you ought to consider big gussets from the 12" pipe to the plate underneath the bricks, so as to distribute the load from the entire plate to the pipe. It would also serve to reduce the amount of moment on the plate to pipe welds.
Also, will the plate be exposed to any heat or will there be brick on top of it? If the fire were built on top of the plate I'd be concerned about the long term effects of the heat on the integrity of the plate and weld.
The primary concern that I'd have with your concept is the bending moment (deflection) in the pipe, caused by the weight as well as width of the load above. I think that it will be critical that your pipe be perfectly aligned with the vertical loads from the chimney.
Thanks for keeping us updated on your cabin progress. It's one of my favorite threads. PS - I think that the girls are right regarding omitting the battens...
Scott
Scott
About any size pipe will handle the weight. It is a matter of keeping it straight. Flanges from pipe to footer are important. Keep the flanges as wide as possible.