100+ yr chimney in log cabin

I have just purchased an old log cabin which was occupied up until two years ago. The fire place was used regularly. My question is what with and how would I line it to make it safer. It is approximatley 12" X 24" inside and 21' tall. It has the original rough limestone suface inside the flue. It is sound and has been maintained. I have the capaibility to do the work, equipment and labor wise. We would like to retain the originality of the fireplace, but make it safer. I realize an insert and flue pipe would be easier and more efficient. But originality is the goal. It does have a traditional cast iron damper.

My thoughts are lining it, pouring a insulation type filler between liner and chimney, capping it and using a damper at the cap. What I don't know is how big should the liner be to handle the fire box and what material would I use between liner and chimney for insulation or would I need anything at all.

If I were building a new one I wouldn't have any questions, but this is a unique problem for us. Any help is greatly appreciated!

Thanks!
Cabinguy

 

Welcome to the forums! I did one (two) for a customer in Western NC a couple of years ago. Yes, installing a lined flue pipe in the chimney flue, installing a good capper is a good start. We went one step further and installed a free standing stove in each fireplace opening, since they were cavernous to begin with. Makes for a secure, controllable, efficient heat. Man, they sure knew how to build fireplaces back in the 1850's.

 

Here is a link to what I believe is your best solution so there is no alterations to the fireplace. There is not to many companys like this one. You will see that theywill refer you to someone in your area. Goodluck Thermocrete Installers | Ceramic Flue Sealant Installer | Thermocrete Flue Sealant

 

The size of your flue liner is determined by the size of your firebox opening. . Example, you don't want an 8x8 liner for a 48" opening . Your chimney, built with stone, has no liner & is not parged on the inside but is sound . You want to maintain originality . The whole place sounds unique . This Thermocrete Sealant , I've only seen it's operation once and it was performed on a new chimney . I'm not sure on it's properties or whether it would bond to soot , creosote or whatever is on the inside of the limestone chimney. Above the damper should be corbelled over to construct the combustion chamber . Above the back part of the damper is the smoke shelf. The distance between the underside of the damper & the top of the opening is the baffle . This should be at least , I like to see 6" . Without actually seeing it , being 100+ yrs old , it doesn't smoke , works well, is structurally sound & well maintained , is built of solid masonry (stone) . Personally , I wouldn't touch it, other than possibly installing a cap on top to stop any water or down draft.I have seen many chimneys built over 100 yrs. ago , without liners that are still standing today and are functional .