1. Understanding the APA Grade Stamp
The stamp in the exhibit reads:
APA RATED SHEATHING 32/16
15/32 INCH (thickness)
SIZED FOR SPACING
EXPOSURE 1 (can handle temporary moisture exposure)
2. Meaning of "32/16"
The numbers 32/16 are the span ratings for the panel:
32 inches = maximum recommended span for roof sheathing (when applied perpendicular to supports).
16 inches = maximum recommended span for floor sheathing (when applied perpendicular to supports).
These ratings are established by APA (The Engineered Wood Association) based on panel thickness, grade, and allowable loads/deflection limits.
3. Applying to the Question
The question asks specifically for maximum recommended span for use in a floor system.
From the stamp:
Floor span rating = 16 inches
Therefore, the correct answer is 16 in.
4. Why Other Options Are Incorrect:
A. 15 in — Not the value given; 16 in is the rating.
C. 32 in — This is for roof applications, not floor systems.
D. 108 in — Not related to APA span ratings; possibly confused with the certification number "NBR-108."
5. NCARB ARE 5.0 PDD Study Guide References:
Content Area: Building Materials & Assemblies — Wood Products
Reference Sources:
APA – The Engineered Wood Association: Panel Span Ratings Guide
Building Construction Illustrated (Ching) — Plywood and OSB Panel Markings
IBC Chapter 23 — Wood span and application requirements
Submit