How many TFIFRM thickness determinations are required for a W-shape column?

The requirement for 24 thickness determinations for a W-shape column is based on industry standards that establish the necessary sample size to ensure an accurate representation of the fireproofing thickness applied. This number is significant as it allows for a comprehensive assessment through various points on the column, which can have irregularities in the application of fireproofing material due to factors like workmanship, surface conditions, and access limitations.

By conducting 24 thickness measurements, inspectors can account for potential variations that might occur during the fireproofing application process. This thorough approach helps to ensure that the specified fireproofing thickness is met uniformly across the entire surface of the column, thereby contributing to the structural safety and fire-resistance of the building. The process also aids in identifying areas that may require rework or attention, minimizing the risk of structural failure during a fire event.

The other options fail to meet the established guidelines that recommend multiple thickness assessments for accuracy and reliability, highlighting the importance of the 24 determinations as the standard for ensuring that fireproofing practices adhere to safety regulations and performance expectations.