I am planning to have a wood stove installed into an old chimney. It will have a new insulated flue liner, backer board behind the stove, etc. but I removed the panelling that covers the chimney now because I was going to remove the panels to leave the chimney exposed and discovered that it is covered with ugly old horsehair plaster. I don't know if the chimney was operated like this or how long it has been there. What I want to know, before I build a hearth for the stove, is if this will be safe in terms of fire resistance and possible fumes? Thank you.