wood insert liner question

[alx123]

hi all. first time posting here.
i will be installing a wood burning insert in a basement through an existing 8x12 flue (inner size 6.5 x 10.5). i need to run about 25 feet liner.
Question: do i go with 6" 316 liner or do i go with 5" (or even 4 ") liner (with a reducer) to make it easier to snake the liner down? i am looking for comments/opinions related to performance, not code. thank you so much guys and gals in advance.

 

[bholler]

i will be installing a wood burning insert in a basement through an existing 8x12 flue (inner size 6.5 x 10.5). i need to run about 25 feet liner.
Question: do i go with 6" 316 liner or do i go with 5" (or even 4 ") liner (with a reducer) to make it easier to snake the liner down? i am looking for comments/opinions related to performance, not code. thank you so much guys and gals in advance.

Well you need to ask the stove manufacturer what is acceptable to run the stove on. But some will allow you to run a 5.5" liner but with that you will still not have enough room for proper insulation. So what I would suggest if your existing clay is in good shape is an ovalised liner that you can insulate. If those liners are already cracked or damaged I would break them out and put in an insulated 6" round

 

[alx123]

thx bholler! existing clay is in good shape, i looked down the other day. from performance perspective, do i really need to insulate?

 

[begreen]

When you looked down in the chimney did you note whether it is a straight shot down? Was there a lot of mortar ooze between the tiles or did it look clean all the way down? If it is a straight and clean shot you might want to look at oval DuraLiner. It's a pre-insulated rigid liner sized for this situation.

 

[bholler]

thx bholler! existing clay is in good shape, i looked down the other day. from performance perspective, do i really need to insulate?

Well there really i no way to tell by looking down it if it is in good condition or not unless it is in really bad shape. You would have to have it scanned by a pro to know that. As far as insulation goes do you have the required clearance to combustibles? If this is an internal chimney you need 2" from the outside of the chimney structure to any combustible material. for an external chimney it is only 1". If you dont have this (which most do not) you need insulation to bring it up to code and protect from a potential fire hazard. also you really want insulation for performance reasons anyway.