Chimney insert question

[wtyamamoto]

Hello all,

I am considering an SS insert for my masonary chimney (see my post "6 inch to 8 inch"). So question, especially for BrotherBart and elkimmeg:

To update, it is a masonary chimney that serves an existing old wood stove in the basement, and a fireplace on the 1st floor. Each has it's own flue, so it's a fairly large structure. It runs through the middle of the house.

I will be installing a new to me secondary burn wood stove with a 6" exit because it's more efficient. The existing flue size has an internal dimension of 6.5 x 11 (external dimensions are 7.5x12 - I assume this is considered and 8x12 flue) which gives an area of 71.5 square inches. This would be under the max 3x requirement for interior chimneys - unless my calculation method is erroneous and I should be using the 7.5x11 measurement.

In the event that it doesn't draft properly because of size and I need to throw an SS liner in, I have a question:

The structure of the chimney in the basement is a hollow tile surround (chimney is covered with red brick on the first floor). The existing tile flue liner is about 16 inches deep into the chimney. The cleanout is located about 12 inches right below the existing pipe entry. Liner kits that I have seen have tees with relatively short horizontal legs. What would I mortar into the hollow tile to reach the tee and liner and give me a connection for the stove pipe?

There is no combustible wall surrounding the hollow tile structure - it is bare.

Thank you all for your input.

Wayne

 

[BrotherBart]

I am trying to visualize what that chimney connection looks like in the basement. I am not good at the visualization stuff.

Does the chimney not have a horizontal clay "thimble" running into it to the vertical flue tiles? That is the usual setup. If so then you run single wall pipe through the thimble and connect it to the tee with your interior single wall pipe connected to the stove at the other end.

 

[wtyamamoto]

Hello BrotherBart,

I don't know EXACTLY what's in there behind the hollow tile yet, but I will have to break through there for install since I would need to get in there to connect the tee, etc. then cover everything back up (mortar, etc.) - that's why I want to see if the stove works ok without liner. I do know how far back the flue is as I can measure from the outside to the flue via the cleanout.

I'm not home right now so will have to double check later, but from recollection, this is the construction:

The existing horizontal mortared into the hollow tile, and I assume all the way to the clay liner, is a steel pipe. I don't recall if there is another steel pipe inset into this pipe which then attaches to the stove pipe or if the pipe coming out of the hollow tile IS the pipe connected to the stove pipe from the stove.

There is no thimble as their is no combusible near the stove and pipe - the chimney's structure in the basement is bare with no stud wall built around it.

Wayne