40 Hour Property and Building Inspection Practice Test

What is the typical size of purlins?

1. 2 x 2

2. 2 x 6

3. 2 x 4 or 2 x 6

4. 4 x 4

The correct answer is: 2 x 4 or 2 x 6

Purlins, which are horizontal members in a roof structure that provide support to the roof deck or sheathing, typically come in sizes that accommodate the loads they support. The most common dimensions for purlins in residential and light commercial applications are usually 2 x 4 or 2 x 6. The selection of these sizes is based on factors such as the span of the roof, the load requirements, and the materials used for roofing. A 2 x 4 purlin is often sufficient for lighter loads or shorter spans, while a 2 x 6 may be used for heavier loads or longer spans. This versatility allows builders and inspectors to understand that both sizes are applicable depending on specific structural needs. By choosing an option that includes both 2 x 4 and 2 x 6 sizes, it accurately reflects the commonly accepted dimensions used in the industry for purlins, making it the most appropriate and comprehensive choice among the options provided.