Cast Iron Insert

[kriss_boy]

Hi,

I understand I need to backfill my cast iron insert fire with vamiculite. That I cannot simply slide the insert into the builders opening and leave a large void behind it.

Can I reuse the old red bricks to form this smaller opening? They will be behind the insert and not on show. Or do I need specific fire bricks for this?

Thanks,

 

[saladdays]

If you leave a void behind the fire the some of the heat will simply gravitate backwards then up the chimney. Vermiculite is effectively insulation.

Ordinary red bricks are fine.