We dont touch the bricks untill they are wirn or cracked bad enough they no longer stay in place. The back bricks in my stove have been cracked for 3 years now. But no need to change them yet.
Ok so because it might be a little harder to do he isnt going to bother with code??
Yes ny uses irc and nfpa211. That says that you need 1" of clearance from the outside of the masonry structure to any combustible material for an external chimney and 2" for an internal chimney. Out of the thousands of chimneys i have looked at almost none have that. So it is very unlikely yours does. And if it doesnt you need insulation.
Honestly nyc is known for having lots of shady sweeps. Just because many of them choose to ignore code doesnt mean doing so is safe or the right way to do it.
I have never heard of the brand but that type in my opinion is absolute junk. We typically use either midweight or heavy wall liners for wood stoves. Standard lightwall works fine but wont hold up as long as the other 2. That 2 ply stuff just is not durable at all.
