What is the impact of using an inappropriate material for patching SFRM?

Using an inappropriate material for patching Spray-Applied Fire-Resistive Material (SFRM) may compromise the fire-resistance of the assembly. The primary function of SFRM is to provide a specific level of fire protection to steel structures, ensuring they maintain structural integrity during exposure to high temperatures.

When materials that do not match the properties of the original SFRM are used for patching, it can lead to various issues. For instance, the thermal conductivity, density, or adhesive properties might differ, which can interfere with how well the fire-resistive coating works in a fire situation. This can result in areas of the structure being less protected than intended, ultimately reducing the assembly's overall fire-resistance rating and potentially endangering structural stability.

The integrity of the fireproofing system relies on uniformity in materials, so using a patch that does not conform to the specifications of the original material may lead to failure in protecting the underlying structural elements during fire exposure. Therefore, choosing the right patching material is critical to maintain the intended level of fire protection and structural safety.