Installing a Drolet 1800 insert this weekend after I sweep my existing chimney (waiting on delivery of my kit from Amazon since the professionals are out a month with appointments). Flue is 13'6" from where top of the stove will be to top of the chimney, guessing another 6" with top plate and rain cap installed. Almost a straight shot down. Cut out the damper and clearanced the throat for the liner last night with a wafer wheel on angle grinder. Chimney is outside the chase and top 6' to 7' is 12"x 9" tile lined.... planning on insulating the liner with 1" kaowool. Anyone think I'll have draft issues? Planning on cutting the damper to block off up to the clearanced section, silicone seams and 2" kaowool on top of it as well as packing the remaining hole around liner with kaowool.