(2.11-002) Insulation above Technolith to Provide Fire Safety for the Compartments Below

If there is a fire in a biome it could conceivably be quite intense - especially if the biome consists of dry grassland or forest.

The heat from a biome fire will presumably affect the deck around the biome. How thick should the insulation be in order to prevent the fire spreading to the compartments below via conducted heat.