Hello. After reading here a bit, I came to the conclusion that it is always a good idea to install a block off plate, and to insulate the liner. I have been around town today looking for Roxul that I have read about to insulate block off plate. I can't find any Roxul but for special order. I stopped into a hearth shop, they told me that they just stuff regular fiberglass insulation around the liner at top, and bottom, and no insulation needed in the middle. Winter is fairly mild here, it will freeze over night but daytime lowest temps are mid 40's-50's. I was planning to do a block off plate, and full liner insulation, but after talking with the local installers at the shop, I'm wondering if that is necessary. I will be running SS liner through terra cotta clay liner. Existing chimney backs to uninsulated garage area, and up through attic. Liner is on the road and will arrive this week. Thanks.