Expert: James Ball - 12/22/2009

Question
Hi James, I know you've probably answered a lot of questions about double sided fireplaces. I thought I had it all figured out when I decided to buy two fireplace inserts and sit them back to back in my opening that is about 38 inches deep.  However, I have since read that you must have a dedicated vent and flu for each fireplace. My question is, if the fireplace inserts are placed back to back is it really illegal/against code to just have the pipe tee off to each one since they are back to back? Not that this matters really, but I have no intention of buring a fire on both sides, and it just seems like it would work so perfectly.  When I try to use the fireplace as is it smokes the house up on one side. I even installed high end glass doors on both sides and stuffed extra insulation around the metal frame but it didn't help much at all.

Answer
Hello Robyn, you can install and use both inserts if the both are vented into their own insulated liners to the top, but they can not go in to the same flue. Check with your local building department and 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.
As far as "smokes the house" this is negative pressure and may still happen even using one insert or the other, try lighting a piece of incense and holding it in front of the open insert door with the damper open, see if the smoke goes up? IF not open a door or window full and re try the smoke it should work, if so then you have to find where the negative pressure is in your home.
Hope this helps
James