It’s not uncommon to see specifications calling for two-hour fire doors. At first glance, it seems logical: more hours must mean better protection? Yet the reality is different. In most cases, such a requirement isn’t necessary and can lead to misunderstandings as well as unnecessary project delays.
Where Does the Confusion Come From?
Fire-resistance requirements vary significantly from one jurisdiction to another, since each country, province, or city may have its own regulations, sometimes stricter than others.
The Role of Fire Doors and Frames
Fire-rated openings are not only about meeting code requirements. Their primary purpose is to protect lives and reduce property damage in the event of a fire. Hollow metal remains the reference material for higher fire ratings, with certified assemblies available for up to three hours. Specifying the correct rating ensures compliance while keeping a project realistic and cost-effective.
About Frame Filling
Frame filling is another frequent source of confusion. A persistent myth suggests that all fire-rated frames must be filled with grout. In reality, very few frames require grout to maintain their fire rating. When it is necessary, grout must be prepared and applied manually, with the right consistency and while keeping the frame properly braced. Pumped grout, plaster, or antifreeze additives should absolutely be avoided.
In Summary
The next time a specification calls for a two-hour fire door, it’s worth checking whether this requirement is truly needed. In many cases, a 90-minute door is more than sufficient and much easier to source. Combined with proper frame installation, it ensures a compliant, reliable opening that’s well integrated into an overall fire safety strategy.
