How does the insulating value of firebrick compare to that of insulating block?

The insulating value of firebrick is indeed significantly less than that of insulating block materials, often measured as less than 1/10th the insulating value. Firebrick is specifically designed to withstand high temperatures and is typically made from materials that have a high thermal conductivity. While it can withstand direct flame and extreme heat, it does not provide the same level of thermal insulation as insulating blocks, which are engineered to minimize heat transfer.

In applications where insulation from heat is crucial, such as in walls or ceilings, insulating blocks offer superior resistance to heat transfer due to their composition, which includes materials specifically chosen for lower thermal conductivity. This makes insulating blocks more effective for thermal insulation. Therefore, option B accurately highlights the significant disparity in the insulating value between the two types of materials.