Chimney insulating roxul application getting squared away

[tjcole50]

As many of you have been helping I am planning my first install, I am not sure how much roxul needs applied to my setup. It is an external masonry chimney. From what i gather so far, I should be stuffing as much roxul as possible up through my damper frame the rectangular metal opening that oval liner is going through? Hope I have terminology correct and make sense of what I'm describing( after i cut an opening to fit flex liner )then add a block off plate right below the existing damper support frame? Is it necessary to drop in roxul from the top of my chimney when my liner will also be insulated and plate applied to the top? thanks again everyone!

 

[begreen]

It won't hurt to stuff the top with roxul but you can skip that if the liner is fully insulated. You have the block off plate idea correct. Definitely stuff the damper area with roxul before putting up the block off plate. Refer to these installs if you need some guidelines.
https://www.hearth.com/econtent/index.php/articles/making_a_block_off_plate/

examples with pictures:
https://www.hearth.com/talk/threads/11697/
https://www.hearth.com/talk/threads/9630/
https://www.hearth.com/talk/threads/47057/
https://www.hearth.com/talk/threads/67219/
https://www.hearth.com/talk/threads/78544/
https://www.hearth.com/talk/threads/80548/