Today I pulled my liner out of my masonry chimney and wrapped it with insulation. While I have everything opened up I will be adding insulation above my block off plate. Pics to follow and will report back through this burn season to see how noticeable my improvements are. First, a question. Inside my fireplace there is a gap on both sides, between the front brick and rear metal shield, currently stuffed with insulation. See pic. I would like to seal this area off and not have exposed insulation, even though its not visible when my insert is installed. Any ideas on best way to seal it off?
![Liner insulation install Liner insulation install](https://www.hearth.com/talk/data/attachments/329/329039-5adc5e94e7573b5a9ce1454c4d044a03.jpg)
![Liner insulation install Liner insulation install](https://www.hearth.com/talk/data/attachments/329/329039-5adc5e94e7573b5a9ce1454c4d044a03.jpg)