u/JAlley2

I’m rebuilding my concrete block firebox for my evaporator. Last year the blocks made it through the season but several cracked in the heat (as I expected). This year I am going to line the concrete block with refractory brick.

My question is, should I use refractory mortar to attach the refractory bricks to the concrete block, or do the refractory bricks give enough insulation that I can use regular mortar? The regular mortar is cheaper and easier to work with so I’m leaning that way. I’m planning to have mortar behind the bricks only and to have the joints between bricks tight but mortar free.

Anyone with experience in this?