Thimble problem (New User)

[duffey]

I have a newly built chimney and Hearth area for a wood cook stove in my kitchen. Its full masonry with an inside wall of brick. The 8" I.D. thimble was placed through an opening in a combustable wall (a header) and is surrounded by brick and mortar. Problem is the area around the Clay tile thimble is out of spec. I only have about 8 inches of brick surrounding it. Code says I need 12". It is however 7 feet up the wall so its not directly behind the stove. I am using 6" double walled stove pipe from the stove to the thimble.
My question is does anyone know of an 6" insulated double walled pipe that will slide into the existing 8" thimble. My thought was that this would create enough insulation to be safe. Thimble is 14" deep into the chimney.
Not that it matters much but the stove is only 27,000 btu. "Vermont Bakers Oven"
I have know one to blame but myself as I told them it was ok, thinking it would be fine that high up the wall.

 

[bholler]

I am afraid you need to either extend the masonry or take it out and put in an insulated thimble. Also what is the required rear clearance?

 

[Michael Golden]

I can tell you that 6" double wall pipe will not fit through an 8" hole......I had an 8" hole drilled in my poured foundation and the pipe would not fit. Good Luck.

 

[duffey]

Rear stove clearance is 10" with double walled pipe and the brick wall reduces that about 30% so I could put it 7" or so away from the wall safely enough. Replacing the thimble on the other hand would almost require building a new chimney. Its 14 inches deep with 7-8 inches brick and mortar all the way around it to the chimney tiles. Maybe I could create an air place around a 6inch pipe inside the thimble and work it out that way.

 

[duffey]

I can tell you that 6" double wall pipe will not fit through an 8" hole......I had an 8" hole drilled in my poured foundation and the pipe would not fit. Good Luck.

How close was it Michael? Were the crimped parts all that would not fit?

 

[ckitch]

I'm not sure it's applicable in this situation but clearance for double wall is six inch and you have eight inch's of brick around the thimble, can't you run the double wall right inside the thimble? Just asking, not saying that's correct or safe way to do it the pro's should give the correct answer, and I'm not one.

 

[duffey]

I'm not sure it's applicable in this situation but clearance for double wall is six inch and you have eight inch's of brick around the thimble, can't you run the double wall right inside the thimble? Just asking, not saying that's correct or safe way to do it the pro's should give the correct answer, and I'm not one.

Thats what I am trying to do but the 6" double wall stove pipe is just over 8" o.d. The tile thimble is 8" I.D.
You are following my line of thinking though!

 

[ckitch]

I used 6" double wall all the way to my liner so it went inside my 8" clay thimble a little ways. Fit in there with a little room to spare (I do have a proper 12" wall path thimble) I just measured Selkirk double wall is only 6 1/2 to 6 3/4

 

[bholler]

No you cant put double wall stove pipe in the wall if class a chimney section would fit that would work but i doubt it would fit. Why would it require a new chimney we do atleast 3 a year and have never had to build a new chimney.

 

[duffey]

No you cant put double wall stove pipe in the wall if class a chimney section would fit that would work but i doubt it would fit. Why would it require a new chimney we do atleast 3 a year and have never had to build a new chimney.

Ok Obviously I am looking for an answer so riddle me this.

• Did you look at the drawings I posted of the way it is built. This is a masonry chimney, built with an inside brick wall, with a thimble connecting the two and brick surrounding the thimble about 7 foot from the floor. My concern is I only have 7 to 8 inches of brick between the thimble and the studs in that wall.
• I am not suggesting putting double walled pipe into a wall. I was suggesting I could create an air space around the inside of that tile thimble to allow for less clearance. YES very much like a class A chimney section (but its 8.5" o.d.) I already have 7-8 of brick surrounding the tile thimble.
• The 14" long TILE Thimble is laid into solid brick and from the front edge of the thimble all the way to the front of the vertical 8 x 8 square TILE liner of the chimney.
• How would you get it out first of all. Maybe chip it apart bit by bit! This would destroy the inside brick wall right? Then how would you join an insulated metal thimble into the tile lined chimney.

Thanks for your help

 

[bholler]

Air space wont do it you need either more masonry or insulated thimble. Yes we would come in cut out the facing brick carefully then remove the brick inside with a demo hammer until we got through the combustible wall then mount the thimble and slide a stainless pipe through to the clay tile. Then relay and brick on the face that need done to get to the thimble face plate. Yes i looked at the drawings and you should not have had it done that way it is not to code

 

[duffey]

I would like it to be safe so I appreciate your honesty. Let me ask another question. You mentioned using chimney pipe. Selkirk superpro chimney 6"chimney pipe says its 8 inch o.d. If this would slide into that TILE thimble all the way to the chimney , would it be safe? specs say it is good for 2" clearance, think that would be enough with 7" of brick and the thimble? If it would fit of course!

 

[bholler]

I feel it would be safe but i dont think it is to code. the only problem i see is what to do where it meets the chimney. If you can seal that area well it would be safe i feel but not sure if it would pass inspection

 

[Michael Golden]

How close was it Michael? Were the crimped parts all that would not fit?

Yes it was the crimped over edge that was holding things up, I'm thinking it needs to be about and 1/8th bigger. He re-drilled at 8 1/2 and it will work fine, but I wanted a tight fit.