To line or not to line?

[rob z.]

Hi everyone,
I'm looking to connect a Jotul F3CB to a cinder block chimney and would appreciate any feedback or opinions regarding whether or not it would be a good idea to line the chimney. the chimney has a 8x8 clay flue tile in it, in good shape, so I am less concerned about safety, more about stove performance. The stove is a 6" pipe, the inside of the tile is 7.25" square. The chimney is 24' tall with no offsets and located on the exterior of the building.
My main questions are: is the size and height of the chimney going to make it difficult to get a good draft going for such a small stove? And, would an insulated liner decrease the amount of potential creosote accumulation?
Thanks in advance for any ideas or input!

 

[bholler]

My main questions are: is the size and height of the chimney going to make it difficult to get a good draft going for such a small stove? And, would an insulated liner decrease the amount of potential creosote accumulation?

Well yes it will preform better with a liner and even better with an insulated one. It will probably work ok running into just the clay liners but no where near as good as it could work. Now as far as the safety issue. First how did you determine that the clay is in good shape? Unless you had it scanned there really is no way to know that you just cant see it well enough without a camera in there. Next do you have the required clearance to combustibles from the outside of the masonry to anything that can burn? For an external chimney you need 1" the whole way and for an internal one you need 2". If you dont have this and you had a chimney fire it is possible for enough heat to transfer through the masonry to ignite the adjacent combustible material

 

[rob z.]

Well yes it will preform better with a liner and even better with an insulated one. It will probably work ok running into just the clay liners but no where near as good as it could work. Now as far as the safety issue. First how did you determine that the clay is in good shape? Unless you had it scanned there really is no way to know that you just cant see it well enough without a camera in there. Next do you have the required clearance to combustibles from the outside of the masonry to anything that can burn? For an external chimney you need 1" the whole way and for an internal one you need 2". If you dont have this and you had a chimney fire it is possible for enough heat to transfer through the masonry to ignite the adjacent combustible material

Good call on the spacing. Although the chimney was built a couple inches away from the siding, the gap has been filled in with mortar. It would be a PITA to chop all that out.

 

[Hogwildz]

Line it, insulated, done

 

[alamance]

I would install an insulated liner if I were you. You will appreciate the benefits of doing so.