Great forum! Here's my dilema. I have a 35-ish year old Heatilator fireplace with a masonry chimney. Squirrel got passed the damper when it was closed so I was taking the damper out to inspect and found out the the smoke shelf has rusted through. Unknowingly many fires have been burned with this condition (nobody got hurt and nothing burned). I did notice that we seemed to have higher draft then normal for sometime. Undoubtedly due to the fact that the air normally routed through the heatilator chamber was going right up the chimney. I have seen some of the nightmare pictures of these Heatilators being torn out of masonry chimney's. Expensive to say the least. I was told it could be torn out in pieces with a grinder and sawzall and a mason could build it back without tearing out the side of the chimney..... YIKES!! My questions are, to which I have had many different answers and none being the same. Can I install an insert stove with full liner installation and fabricating a block off plate in place of damper and running lining through it? It would also be capped at the top of the chimney. I was also thinking of fabricating a sheetmetal patch to cover smoke shelf and sealing it up. Recomendations for an insert in a 1000 sq.ft. house with cathedral 12-12 pitch ceiling, Tin roof with 1" foam insulation between rafters. Ceiling fan for circulating heat back to floor from sleeping loft. Concrete block walls. Located in Northern Va. Yes, it would be the essential part of the heating system. I would lean towards a bigger stove given lack of insulation. Thanks in advance for any and all advice.