Expert: James Ball - 9/27/2009

Question
We have an 18th century home in Southern New Jersey with a very large 6 foot by 5 foot cooking hearth located centrally in our home.  For the most part the chimney is structurally sound; however, the mortar has loosened from the inner and outer brick walls very high up in the flue causing the chimney to smoke into our attic space. The chimney above our roof line has been rebuilt.  We are currently researching ways to reline our chimney with safe materials.  To complicate matters, there are two flue openings going up to the top of the chimney making the flue we want to repair not perfectly straight up.  For this reason, we are looking into a flexible liner.  My questions is, if we still want to use the fireplace for cooking, how large must the liner be in order to have sufficient draft.  If there are any little tricks we can use for getting maximum draft, I'd also like to know that as well.

Answer
Hello Joyce, as far as draft goes if you want it to go up the chimney you need enough make up air.
As far as re lining, you may do better with a coating http://www.thermocreteusa.com/ or pour in place liner http://goldenflue.com/

I would have a local Certified Chimney Sweep (www.csia.org, there you can look up by zip code to find one near you) take a first hand look at what you have they should be able to help.
Hope this helps
James