When should I select Insul Cast instead?

When should I select Insul Cast instead?

Insul Cast is a backup insulating product that can be applied under the hearth, behind the firebox, or over the dome in a fire pit or bake oven. It is ideal as an insulator for bread and pizza ovens, and should be applied with a minimum thickness of 2”. You will need 6 lbs. per square foot when applied 2” thick.