Which type of glass can be used in fire doors?

• A. Wired glass
• B. Laminated glass
• C. Tempered glass
• D. Ordinary glass

Answer: (A)

Fire doors must use glazing that is rated for fire resistance and that will stay in the door long enough to slow the fire’s spread. Wired glass is designed for this use because the embedded wire mesh helps hold the glass together when exposed to heat, reducing the likelihood of large shards falling out and helping the door maintain its barrier for the required duration.

Ordinary glass would fail more quickly and is not suitable for fire doors. Tempered and laminated glass can be used in some fire-door assemblies, but only when they are part of a listed, labeled fire door system. In the context of this question, wired glass is the type traditionally associated with fire-door glazing.