Which factor does NOT affect the bond strength of SFRM?

The bond strength of Spray-Applied Fire-Resistive Material (SFRM) is influenced by various factors, including surface cleanliness, application temperature, and humidity levels. However, the color of SFRM does not impact its bond strength.

Surface cleanliness is crucial because contaminants like dust, grease, or moisture can interfere with the adhesion of the SFRM to the substrate. If the surface is not properly prepared and clean, the bond could weaken, compromising the fire resistance.

Application temperature plays a significant role as well. The material needs to be applied within specified temperature ranges to ensure proper curing and adherence. Extreme temperatures can lead to issues such as inadequate bonding or improper drying.

Humidity levels are also important; high humidity can affect the curing process and might lead to adhesion problems. Excessive moisture in the air during application could lead to water in the mix or on the surface, impacting how well the SFRM bonds.

In contrast, the color of SFRM does not represent a technical factor that influences bond strength. While color choices may be relevant for aesthetic purposes or regulatory requirements, they have no bearing on the physical properties that determine how well the SFRM adheres to surfaces. This distinction clarifies that bond strength is primarily