A TFIFRM thickness testing project is 13,500 sf and has columns, primary beams, secondary beams, and trusses. How many thickness tests do you perform?

• A. 6
• B. 8
• C. 10
• D. 12

Answer: (B)

Thickness testing should give you a representative picture of how the fireproofing is performing across all the different structural elements in the project. When you have multiple types of members—columns, primary beams, secondary beams, and trusses—the best approach is to apply the same number of thickness tests to each category. This keeps sampling balanced so you catch variations that can occur due to access, angles, spray technique, or geometry, rather than concentrating tests on one type and missing issues in another.

In this project, applying an equal test count to each category aligns with that balanced sampling idea, which is why the given answer matches. If you tested too few items, you might miss thickness variation in some members; testing more would add effort without necessarily improving reliability for this project size.