Which condition must be controlled when preparing SFRM samples for density testing?

When preparing Spray-Applied Fire-Resistive Materials (SFRM) samples for density testing, controlling both temperature and humidity is paramount. These environmental conditions can significantly affect the properties and performance of the fireproofing material.

Temperature plays a crucial role in the curing process of SFRM. If the temperature is too low, the material may not cure properly, affecting its density and performance when subjected to fire. Conversely, excessively high temperatures can speed up the curing too much, leading to inconsistent results.

Humidity, on the other hand, impacts how well the material adheres and cures. High humidity can alter the moisture content of the mix, which in turn influences the density and other mechanical properties of the cured product. Low humidity conditions might also affect how the SFRM material settles and cures after application.

By ensuring both temperature and humidity are controlled, the testing results for the density of SFRM will accurately reflect its real-world performance characteristics, leading to reliable and safe fireproofing applications.