White Papers ─── November 22, 2022
The Complexity of Fire Ratings and the Impact of Life Safety
Author: Cody Lyzenga
Many people have heard terms like “fire rating” or “fire wall.” Fire safety is a staple concept in the world of architecture. One of the main roles of Architects is their responsibility for the life safety of any building that they design. Life safety for the occupants of a building in case of a fire becomes a priority very early in the design process. What most people do not know is that there are many different types of fire rating products and testing that need to be accounted for in a building design. We will dive into some of the fire-related safety items in this paper.
A fire separation is one of the most common tools to protect occupants of a building. It is most commonly a framed wall with Type ‘X’ gypsum board on each side. It will create a solid barrier between rooms in order to stop the spread of fire from one location to another. It is required in locations based on building size and use. Most commercial buildings will have a fire separation protecting the service rooms.
Spatial separations are reserved for exterior walls of buildings when the building is too close to the property line or neighbouring buildings. This protects the adjacent structures if one building catches fire. The closer a building is to the property line, the more robust the spatial separation is required to be. An interesting fact about spatial separations is that they are allowed to have windows but only up to a maximum area, depending on the distance to the property line.
A fire wall is one of the most misunderstood terms in the construction industry. A fire wall is a very specific barrier. It typically must be made of concrete, and it is required to have a parapet that extends above the roof of the building. This type of barrier can be used to reclassify and separate buildings in order to achieve a size that would not otherwise be achievable. Can you spot the firewall in this picture?
Fire Resistance Ratings
This term does not refer to a type of fire protection but instead refers to the measurement used to determine the strength of a fire protection element. The measurement is the length of time it takes for the element to fail due to a fire. This is measured in minutes and hours, and the requirement can be anywhere from 15 minutes to four hours.
Flame Spread Ratings
A flame spread rating is almost exactly as it sounds. It refers to the strength of a material to resist a fire burning across its surface. A fun fact is that every material used in our houses is required to have a flame-spread rating, and most of these are typically tested behind the scenes by product manufacturers.
If a building is over a certain size or height or has a dangerous use, it may be required to be of non-combustible construction. Most single-family homes are built out of wood, and this makes the entire building combustible. Larger commercial buildings are required to be built of steel or concrete in order to prevent large fires that would be out of control far too quickly.
Fire blocks are small components that prevent the spread of fire in hidden areas of a building, such as a crawl space or an attic. They can be made of wood, drywall, or thin pieces of metal.
These are just some of the many types of fire safety that go into the design of a building. These safety elements create time for occupants to exit the building safely. They also prevent fires from becoming too large too fast. As you can see, there are many facets to the fire protection of a building that architectural firms and city officials must review to make sure that a building is safe for its occupants.
Source: BC Building Code, 2018 Edition