Q: Hi Jason, My chimney opening measures 8 1/2? x? 34 inches…there is no damper system now. can I use a standard size or will I need a custom fit? price? – TB
A: TB, The closest standard size Chimney Balloon to your flue opening is a 36″X15″. That is a little more than the 6″ too deep and 2″ too wide. The width won’t be a problem but the depth might be a bit difficult. It will benefit you, in this case, to go ahead and order a custom Chimney Balloon for a 36×9. A 36×15 will certainly work but you will find the custom Chimney Balloon to be easier to install and uninstall. – Jason