Expert: Steve Tavares - 12/13/2009

Question
Hi Steve,
Thank you for taking the time to read & respond to my question.  We have an existing double-sided fireplace in our home that was built in the 1960s. We recently had both sides cleaned and opened up one side that was previously sealed.  Now we know why it was sealed!  When having a fire in the kitchen side of the fireplace smoke is drawn into the living room via the unused side; even though the flu (sp) is closed.  I think it's due to a high/low pressure draw.  How can this be fixed? Will having simultaneous fires in both sides stop this? Thank you!
T

Answer
This sounds like negative pressure to me. You have negative pressure in one room and so that room sucks in air from outside via the chimney. Now you have smoke coming out of the other chimney and some of that is being drawn into the room that has the negative air issue.

What I would suggest is a lock top damper on both flus. This will allow you to close one chimney when your not using it and allow you to open the other chimney when you want to burn in it.

Here is a link to a website that has these.

http://www.homesaver.com/content/locktop/about_locktop_dampers.aspx

Its something worth looking into.

Hope this helps.