What is the maximum diameter of a hole that can be bored in a joist?

The maximum diameter of a hole that can be bored in a joist is typically 1/3rd of the depth of the joist. This guideline is based on the need to maintain the structural integrity of the joist while allowing for necessary plumbing, wiring, or ductwork to pass through. Boring a hole greater than this limit can significantly weaken the joist, compromising its load-bearing capabilities.

In design and construction practices, this 1/3 rule has been established to prevent excessive stress concentration around the hole. When holes are kept to this maximum size, the remaining material in the joist can adequately support the structural loads. It is crucial for maintaining safety and ensuring compliance with building codes that address structural support.

Other options suggest either smaller or larger hole diameters, which would not align with standard practices. Holes smaller than 1/3rd would not be utilized efficiently for necessary functions, while allowing holes larger than this limit could lead to structural failures. Thus, understanding and adhering to the specified guidelines is vital in HVAC and construction work to preserve safety and functionality.