Extending chimney

[Rob711]

I’m going to have house renovated basically adding 2nd floor. Keeping existing 90yr old fireplace that I have installed my intrepid along with 6” stainless liner.
This external masonry chimney will be extended. Could I just get a stainless collar and add stainless flex? Or do I have to purchase one continuous length?

 

[bholler]

I’m going to have house renovated basically adding 2nd floor. Keeping existing 90yr old fireplace that I have installed my intrepid along with 6” stainless liner.
This external masonry chimney will be extended. Could I just get a stainless collar and add stainless flex? Or do I have to purchase one continuous length?

You can add a section with a coupler.