Understanding Notional, Nominal, and Upgraded Fire Doors: When to Upgrade
We are often asked to explain the differences between notional fire doors, nominal fire doors, and upgraded fire doors and how these differ from certified fire doors. There can be a lot of confusion surrounding fire doors, so we’ve compiled this short explanation.
What are Nominal Fire Doors?
A nominal fire door is typically made from timber and is designed to provide fire resistance for a specified duration. However, unlike certified fire doors, which have undergone rigorous performance testing to determine their fire rating, nominal fire doors rely solely on the opinion of a fire door inspector regarding their performance.
An Explanation of Notional Fire Doors
A notional fire door meets the fire resistance standards that were applicable at the time of its construction. However, these doors may not align with the latest codes, regulations, and tests. They may lack essential features such as intumescent strips and smoke seals, and their construction may not adhere to current standards.
Stipulations for Upgraded Fire Doors
An upgraded fire door is defined as a notional fire door that has been enhanced with additional features, such as intumescent strips, smoke seals, and sometimes a protected letterbox, if necessary. However, simply adding these features to any door does not make it an upgraded fire door. The door’s overall condition and core construction are crucial for its fire resistance. To truly enhance a door’s performance, it must match the specifications of a certified fire door. For instance, adding features to a lightweight door with thin panels will not convert it into an effective fire door.
Fire Door Ratings and the Upgrade Process
Today, fire doors undergo performance tests to determine their fire resistance rating, which typically ranges from FD20 (offering 20 minutes of fire resistance) to FD120 (providing 120 minutes of fire resistance). Nominal and notional fire doors do not carry test evidence or certification, making them riskier in terms of fire resistance. This aspect should be carefully noted in any fire risk assessment conducted on buildings containing these types of doors.
In situations where installing new fire doors is not feasible, upgrading suitable existing doors can be an effective strategy for enhancing safety, such as found in heritage buildings. The process begins with assessing the door’s condition and suitability. Following this evaluation, necessary repairs and improvements should be undertaken to bring the door as close as possible to the performance level of a certified fire door, but often taking a risk approach.