NFPA 220 fire resistive ratings for Type II construction are represented by which of the following descriptions?

• A. A three-number sequence representing ratings for three building elements
• B. They are expressed as a single two-digit code per element
• C. They are not defined in NFPA 220
• D. They are presented as three numbers corresponding to external factors

Answer: (A)

NFPA 220 uses a compact three-number code to express the fire-resistance requirements for Type II construction. Each number in the sequence is the fire-resistance rating, in hours, for one of the three main building elements that NFPA 220 specifies for this construction type. Those three elements are the exterior walls, the interior bearing walls (the structural vertical elements), and the floor-ceiling assembly (the primary horizontal element). This coding lets designers quickly see the required resistance level for each key component without listing them separately. It isn’t a single two-digit code per element, NFPA 220 does define these ratings, and it isn’t based on external factors.