Tap into chimney?

[tjoyce511]

I have a terra-cotta rectangular flue in a chimney that is about 25 yrs old. The chimney services a rarely-used fireplace inside my home, and the flue and chimney are in excellent shape. The exterior side of the chimney is in my garage. My question is: Can I tap into this chimney (above the fireplace damper, of course) from the garage side and install a thimble for a wood furnace? I won't ever be burning the fireplace and furnace together.

 

[Backroads]

I believe that it's not allowed by CODE. But someone else with more experience with installs might know better.

 

[fossil]

Can't install a solid-fuel burning appliance in a garage, and can't have two appliances exhausting into a common flue. Rick

 

[Tfin]

In Maine I believe you can have a woodstove in a garage as long as you don't store any cans of gasoline. I'm sure its different everywhere though.

You'll have to check with your local codes/home owners insurance policy.

 

[fossil]

In Maine I believe you can have a woodstove in a garage as long as you don't store any cans of gasoline.

Even if that's true (which it may well be, I dunno), the woodburner's gonna need its own completely separate stovepipe/chimney unless the fireplace gets decommissioned and sealed up. Rick

 

[Adios Pantalones]

So I could not put a wood fired boile in the basement hooked into the same liner as the insert on the first floor?

 

[fossil]

The code experts will correct me if I'm wrong, but I don't believe they can share a liner. They can share a chimney structure, but they need separate flues all the way to daylight. The danger involved is flue gases from an operating unit infiltrating the living space through the idle unit. Rick

EDIT: Plus, if you were to try and burn them both at the same time, they wouldn't share that flue gracefully...one would inevitably "out-draw" the other, and you'd likely fill your house with smoke & CO in short order. Rick

 

[Adios Pantalones]

Fossil- that makes a mess of sense- especially if there's any blockage- the second appliance may be the path of least resistance, and the first appliance may not even extinguish due to choking itself.

 

[Tfin]

In Maine I believe you can have a woodstove in a garage as long as you don't store any cans of gasoline.

Even if that's true (which it may well be, I dunno), the woodburner's gonna need its own completely separate stovepipe/chimney unless the fireplace gets decommissioned and sealed up. Rick

Agreed.

 

[bluefrier]

The code experts will correct me if I'm wrong, but I don't believe they can share a liner. They can share a chimney structure, but they need separate flues all the way to daylight. The danger involved is flue gases from an operating unit infiltrating the living space through the idle unit. Rick

EDIT: Plus, if you were to try and burn them both at the same time, they wouldn't share that flue gracefully...one would inevitably "out-draw" the other, and you'd likely fill your house with smoke & CO in short order. Rick

Exactly right!

 

[tjoyce511]

Thanks to everyone for your prompt replies. The furnace I am considering is one of the wood gasification types mentioned here (EKO, or Econoburn). If code allows the furnace in my garage, I will definitely be sealing-up the fireplace. If I can't do the garage install, the .I may consider building a "shed" and putting the thing outdoors...Tom

 

[lugoismad]

Can't install a solid-fuel burning appliance in a garage, and can't have two appliances exhausting into a common flue. Rick

Someone on here told me that.

I've spoken with my state and county board of building inspectors, and the man who wrote my states fire code. They all said that there was absolutely no issue with installing a wood burning furnace in my garage.

I had my fire chief out to inspect my garage before ordering and installing the chimney, and again, he said there was no issue with it as long as I installed it per the proper clearances.

Edit: Let me add something here. They DID say I'm not allowed to draw cold air for the blower from the garage, but I won't be.

 

[fossil]

Whatever. Local jurisdictions have the final say, I guess. If I passed along bum info, I sincerely apologize. What I do know is that this is what NFPA 211 (2006) sez:

12.2.3 Solid fuel-burning appliances shall not be installed in any location where gasoline or any other flammable vapors or gases are present.

12.2.4 Solid fuel-burning appliances shall not be installed in any garage.

Rick

 

[Jags]

Whatever. Local jurisdictions have the final say, I guess. If I passed along bum info, I sincerely apologize. What I do know is that this is what NFPA 211 (2006) sez:

12.2.3 Solid fuel-burning appliances shall not be installed in any location where gasoline or any other flammable vapors or gases are present.

12.2.4 Solid fuel-burning appliances shall not be installed in any garage.

Rick

Define "shall not"! :lol:

 

[fossil]

...Define "shall not"! :lol:

Oh jeez...aren't we still working on "inhale" and "have sex"? :wow: Rick

 

[Jags]

...Define "shall not"! :lol:

Oh jeez...aren't we still working on "inhale" and "have sex"? :wow: Rick

I was thinking more of "shall not be infringed"

 

[Steve Z]

I'm in the process of re-installing a wood heater (after getting my oil "budget" plan in the mail) too suppliment the Glenwood cookstove I've always used. This second stove was removed because it shared the same flue as the oil burner and insurence said no. While I never had a problem with it that way, this re-install will include a stainless steel flex liner for the heater.

 

[fossil]

I'm in the process of re-installing a wood heater (after getting my oil "budget" plan in the mail) too suppliment the Glenwood cookstove I've always used. This second stove was removed because it shared the same flue as the oil burner and insurence said no. While I never had a problem with it that way, this re-install will include a stainless steel flex liner for the heater.

I think there may be some local jurisdictions that will approve an oil-burner and a wood-burner sharing a flue. I'm not aware of any that will approve two wood-burners sharing a flue. In any case, your insurance company is likely to look at NFPA211 and say no...it's the conservative thing to do. Anyway, I think you'll get better (and safer) performance out of your appliances if they each have their own airflow path, from intake to exhaust to daylight. I'm intrigued by the old Glenwood...are there pics of it anywhere on here? Rick

 

[precaud]

My question is: Can I tap into this chimney (above the fireplace damper, of course) from the garage side and install a thimble for a wood furnace? I won't ever be burning the fireplace and furnace together.

I can see where you'd have draft problems with that arrangement.

I faced a similar situation last winter, wanting to put a woodstove in my basement workspace. The natural gas boiler down there vents into a huge 13x13 terra cotta lined chimney - way oversized for the boiler's 6" exhaust . The stove and the boiler would never be operating at the same time (the boiler hardly ever comes on any more except on the coldest nights.) So I decided to run a 5" stainless rigid liner up the middle, which leaves plenty of area for the boiler exhaust. I had to fab a piece to secure the liner at the top of the chimney, see the pic. Other than that, it was just like any other liner install - a thimble through the brick and terra cotta, and a service entrance door on the other side for easy cleaning. I finished it right around the new year and it works great.