fire resistive covering material; fireproof coating material
Technical term used in construction and fire safety for materials applied to structural elements to provide fire resistance.
The steel frame is covered with fire resistive covering material.
Please check the thickness of the fireproof coating material.
耐火材 is a broader term for fire-resistant materials in general, while 耐火被覆材 specifically refers to materials used for covering or coating structural elements.
耐火構造 refers to the fire-resistant construction or structure itself, whereas 耐火被覆材 is the material used to achieve that fire resistance.
Compound of 耐火 (fire resistance) + 被覆 (covering) + 材 (material). A straightforward technical term with no unusual etymology.