What are these? They are light, closely spaced members that span between beams or bearing walls. Typical sizes are 2x6, 2x8, and 2x12. Typical spacings are 12, 16, and 24 inches on center. The typical maximum normal span is 20 feet, but spans up to 25 feet are often used.

A) 2x6
B) 2x8
C) 2x12
D) All of the above

The term refers to joists, which are horizontal structural elements in construction with typical spacings of 12, 16, or 24 inches, and the conversion of 16 inches to centimeters is 40.64 cm.

Explanation:

The question refers to joists, which are horizontal structural elements used to support loads over open spaces, often between beams and bearing walls in construction. The typical sizes mentioned like 2x6, 2x8, 2x12 represent the nominal cross-sectional dimensions in inches, where the '2x' indicates the thickness in inches and the subsequent number represents the depth.

The typical spacing of these joists can be 12, 16, or 24 inches on center (abbreviated as 'oc'), and the typical maximum span (without additional support) is 20 feet, but spans up to 25 feet are sometimes implemented in construction. These measurements are critical in ensuring that the floor or ceiling structure is safe, stable, and complies with building codes. When converting to metric units, the spacing between vertical studs, which are commonly placed 16 inches apart, can be calculated as follows:

1 inch = 2.54 centimeters

Therefore, 16.0 inches x 2.54 cm/inch = 40.64 centimeters