block Chimney requirement

tewplanman · By: **tewplanman** On: Mon Jan 29, 2007 11:59 pm

Hello All,
New to the board, just purchase a US stove 1600G wood/coal hand fed. A few guys here have one and seem to like it

I have a weekend house in PA 2500sq feet 2 stories. The chimney was build by the guy who had the house before me ( got it on a forclosure) so im still putting humpty dumpty back together again. Great deal at 68K but lots of work. Anyway he build a chimney out of 12 inch concrete block with no liner, build it right against the house and put a clay thimble thorough the block foundation into the chimney.

Does this seem right to you, can I use it for my US stove 1600G or do I have to install a liner

Thanks for your help

Tom

LsFarm · By: **LsFarm** On: Tue Jan 30, 2007 12:08 am

Hi Tom, I'm sure that you can use the chimney as is if you are burning anthracite coal. If you burn wood or bituminous coal the rough inner surface will make cleaning or sweeping the chimney very difficult. An anthracite fire makes only a little dust. Does the base of the chimney have a cleanout with a metal door on it??

If you don't get the draft you want or need, then you can always spend the money and put in an 8" SS liner. This is what I did on my chimney, because it is fairly short, and I wanted to be able to clean it easily.

But you should be able to use it as long as it doesn't have any gaps in the mortor joints and is fully outside, with no chance of fumes getting into the house through a possible porous concrete block.

Take care, Greg L

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Yanche · By: **Yanche** On: Tue Jan 30, 2007 12:55 am

As Greg says if the construction is sound you can use it with anthracite coal. I grew up in a house heated with anthracite with a brick chimney with no liner. Used for 40 years with no problems. It was lined when freeze thaw cycles deteriorated the portion above the roof. An unlined masonry chimney does NOT meet the NFPA 211 fire code.

Yanche

tewplanman · By: **tewplanman** On: Tue Jan 30, 2007 1:22 am

NFPA fire code ??? Anyone got a web link to a pdf??? I plan on burning wood and coal. I guess Ill use the block chimney to start. If i run into a problem I can hang a double walled stainless off the side. I plan on putting in a dual install with an oil hot air unit since i have a tank in basement. Most of the post here seem to indicate that its not good to try and vent a wood/coal burner into the same chimney as a oil or gas unit. Im wondering if I could rig a set of controlls on stack to prevent the backflow of gas?? Any ideas out there for this type of install . Also does it pay to look into one of those power vents from Field controls for the oil unit or is the stainless chimney cheeper

Thanks again to all for the help,

Tom

Yanche · By: **Yanche** On: Tue Jan 30, 2007 1:40 am

tewplanman wrote:NFPA fire code ??? ... Snip ... Most of the post here seem to indicate that its not good to try and vent a wood/coal burner into the same chimney as a oil or gas unit.

The National Fire Protection Association is at: http://www.nfpa.org/
You can not download any of the documents for free. You can however read them a page at a time. Printing is locked out. The document you want is "NFPA 211: Standard for Chimneys, Fireplaces, Vents, and Solid Fuel-Burning Appliances". Just put 211 in the search box.

You can NOT share any solid fuel flue chimney and meet NFPA 211.

Yanche

Berlin · By: **Berlin** On: Tue Jan 30, 2007 2:24 am

when unlined chimneys are used for wood, creosote will quickly leach through the mortar joints. in the instance of a chimney fire the creosote that has leached through will begain to smoulder and burn, the building structure then quickly ignites. this in addtion to the lack of thermal mass in single-brick thickness unlined chimneys (to absorb heat of a chimney fire w/out becoming hot enough to ignite nearby combustables) is the reason for unlined chimneys being VERY dangerous for burning wood. burn only coal and you will be ok, however the acids will eat away the block in a few years. i would not burn wood with that chimney unless you line it.

Mega_Me · By: **Mega_Me** On: Tue Jan 30, 2007 11:44 am

Tom,

Congrats on your furnace purchase, I'm sure you'll be happy with it. Once I got through the "learning curve", it works well. It has saved us tremendously on the nat. gas bill.

I HIGHLY recommend you either get a liner put in, or tear it down and have it reconstructed. I had mine built for close to 2 grand. It would have been much cheaper but we wanted a brick veneer on it.

As a career firefighter, I have seen more "chimney fires" in unlined chimneys than anything else. Although it really was not the chimney that was on fire, it was the combustables around it. These chimneys were unlined like yours, or were old brick chimneys. The heat, etc., worked its way through the deteriorated mortar joints and caused the fire within the walls of the structure. Most of these people had never had them cleaned or inspected, and really had no business burning ANYTHING in their fireplace/stoves. I'm no chimney expert but I had mine built by the amish and the guy had been building them for years, so I was pretty comfortable in his abilities.

I posted some pics of my chimney construction to give you an idea what I have. It works well with my furnace (same as yours).

Mega_Me · By: **Mega_Me** On: Tue Jan 30, 2007 11:47 am

More pics,

Mega_Me · By: **Mega_Me** On: Tue Jan 30, 2007 11:57 am

Stove connection,

I used the 6" single wall pipe from the stove to the thimble. The pipe goes all the way into the thimble and ends aprox 1/4 to 1/2" past the liner surface. The small gap between the liner and the pipe on the inside was sealed with high heat furnace cement.

Hope this helps or at least gives you some ideas.

I'm not sure if you saw these posts;

http://www.nepadigital.com/bb/viewtopic.php?t=487&postdays=0&postorder=asc&start=0

Let me know if you need any other pics/details to help with your install, be glad to help!

Joe

Yanche · By: **Yanche** On: Tue Jan 30, 2007 4:05 pm

Mega_Me wrote:I posted some pics of my chimney construction to give you an idea what I have.

Nice masonry chimney. Lots of questions.... Was insulation stuffed into the hollow areas of the chimney block? What kind? Was the mortar used for the tile liner joints different from the block mortar? Type S for the blocks and bricks? Refractory cement for the tile liner joints? Does it have a clean out? Does the clay liner go to just above the clay liner or below it? If it tile goes below the top of the clay liner how was the clean out door cut into the liner?

Yanche

LsFarm · By: **LsFarm** On: Tue Jan 30, 2007 6:03 pm

Yanche, the clay liner that I had in my first rendition of my chimney could be purchased with pre-cut holes for a flue pipe.

For the clean out at the bottom I used a masonry wheel on my air cut-off tool, I was amazed at how well the little wheel cut the clay liner.

Greg L

tewplanman · By: **tewplanman** On: Tue Jan 30, 2007 9:24 pm

Since I can't use the same chimney for two burners wood/coal and oil. I will probably hang a second stainless off of the existing block and use it for my Clayton wood/coal burner. Guess I can use the block for the oil burner

Thanks to everyone for the help

Regards
Tom