Block off plate, roxul, code?

[begreen]

You can use cement board like Durock Nex-Gen

 

[qwertyjjj]

You can use cement board like Durock Nex-Gen

Createa ledge with screws in the brick or other concrete board to support the block off plate? I suppose the benefit of sheet metal is that it can be bent at the edges.

 

[begreen]

I suppose the benefit of sheet metal is that it can be bent at the edges.

Yes. That's right. There are some good instruction in the articles section and there are examples at the end of this wiki post.
https://www.hearth.com/talk/wiki/why-damper-seal-is-needed/

 

[qwertyjjj]

It's t there any clearance requirement behind the stove or distance between top of stove and the block off plate?

I should add that there is no damper in the liner so cold air will still come down there.

 

[begreen]

No, but it's nice to have good working room above the insert to connect the liner if possible.

 

[bholler]

It's t there any clearance requirement behind the stove or distance between top of stove and the block off plate?

I should add that there is no damper in the liner so cold air will still come down there.

There is never a damper in the liner (whell almost never) for an insert. But if you close the air inlets very little air will come in. And you could always start a fire.

 

[qwertyjjj]

You can use cement board like Durock Nex-Gen

Finex fiber cement panel - same thing?
I'm finding it difficult to get big sheet metal. Hardware stores only sell small panels.

Do you have to use heat silicone and to what temperature must it be rated?

 

[begreen]

I haven't heard of Finex fiber cement panel, but I suspect Durock would be less expensive.

Two 2'x3' metal sheets could be pop riveted together to work. I think there is an example of this in the links provided earlier. Regular silicone is fine for the perimeter sealing.