Expert: Paul Karthaeuser - 1/18/2012

Question
I have an old metal heatilator It has never worked properly since we bought our house it is set in masonry and the back wall of the metal is warped and we get a lot of smoke backdraft.
I would like to cut it out using a sawsall and have a brick firebox built in its place.
is this somethiang that can be done without destorying or rebuilding the existing masonry around the old heatilator

Answer
David,

Yes, but it is very involved.  In fact, only a handful of us do this type of work in the chimney profession.  We call it a root canal!  I use an oxygen/acetylene torch kit to remove the firebox and smoke chamber when I do any root canals such as for fireplace restorations, for installations of wood burning inserts or pellet inserts following the removal process.  

There is one person in the chimney profession that I know of who has written a paper with explicit instructions on the subject of performing a fireplace root canal.  You may be able to find information on the web by googling Steve Kuber and fireplace root canal.  It was published many years ago in a professional chimney sweeping magazine for industry professionals.  I believe that was sometime in the mid-eighties.  The name of the publication was Sweeping Magazine.  

Some other individuals use electric plasma cutters and diamond bladed grinder tools for partial removals.  I highly recommend the use of hearing protection and full face mask shields for the removal.  The steel form fireplace you are describing is actually two 1/4" plates of steel separated by an air space between them with baffles in various locations between the plates of steel.  This air space provided the circulation chamber for air to flow around the firebox and provide a cooling effect that allowed for these fireplaces to be installed with reduced clearances at the time when there were no other fireplaces such as factory built fireplaces or "zero clearance" fireplaces.  
Once the firebox and smoke chamber are removed.  They are one solid, continuous entity.  Once they are removed the smoke chamber will need to be parge coated and the firebox constructed according to current code.  I would highly recommend at that time that the flue lining be inspected by means of an internal video camera scan system to verify the integrity of the flue lining.  
In this whole process there should be no need for any damage or alteration of the original fireplace face material or for it to be removed.  The original face brick or stone should not be affected as it is not part of the actual chimney or fireplace system and is only facing material for aesthetics in the room.  All of the work should be able to be performed within the firebox and smoke chamber without even the slightest movement of the face materials if done properly.  This is a tremendous undertaking even for a very "handy" person but experience and knowledge of the construction and installation of these types of fireplaces is especially helpful.  Someone who has many of these removals under their belt will still be involved in the process for many hours or the better part of a full day to do this.  Another very important thing is to be sure and have an exhaust fan mounted to the top of the flue and running continuously during this whole process to vent any dust, torch gases and heat while the firebox is being removed.
I don't think you will have very much luck using a sawzall and a case of bi-metal blades honestly. Personally, I think it is worth hiring a professional with experience to do this part of the project, especially after having done many of these myself.

I hope my response has been informative and helpful.  Please feel free to ask any follow up questions you may have.  Also if you could, please take a moment and rate my response to your question on this website.  Thank you.

Paul