Duravent Install & Frame Cut-Out
Duravent is one of two venting manufacturers certified to work with Flare Fireplaces. The flue pipe should be 3x5, 4x6, or 5x8 diameter concentric pipe, B-Vent will not work. Below you will find the specific cut-out size for each component. Finally, use the chart to verify the cut-out dimensions for your job.
*Most importantly, if you have any questions contact Duravent for further assistance.
Because the table is taken from the Duravent Install Manual you'll find more details at http://www.duravent.com.