Insulating Fire bricks vs Ceramic fibre board

[Laura McNally]

Hi, wondering if anyone has used insulating fire bricks instead of fibre board for the hearth below the cooking floor and if so what side they laid them on. I have a bunch so wanted to know if this is just as good of a solution (as in as strong and heat reflexion) or if I should just get fibre board. Thanks

[david s]

They are a great solution especially if you don’t have to pay for them. One big advantage is that they’re dry unlike a vermicrete slab that requires drying before it’ll insulate properly. IFB’s are made in many different sizes, but you need a min of 3” preferably 4” of underfloor insulation.

[Laura McNally]

Thanks so much for your response. I will definitely be going this route then. I presume I can just lay the IFB dry versus having to mortar them. Also does the pattern I lay these in matter if I am laying my cast cooking floor ontop.