What is the closest to the edge that a hole may be drilled in a floor joist?

In Virginia, as well as in many construction guidelines, the general rule for drilling holes in floor joists is to maintain a minimum distance from the edge of the joist to prevent significant weakening of the structural integrity. Drilling too close to the edge can compromise the joist's load-bearing capacity and could lead to structural failure.

The minimum distance of 2 inches from the edge is commonly stipulated because this allows for sufficient material to remain around the hole, thus maintaining strength and preventing potential splitting or damage over time. This 2-inch guideline is a widely accepted standard in the construction industry, ensuring safety and compliance with building codes.

On the other hand, the other distances provided, such as 1 inch, 1.5 inches, and 3 inches, do not align with these safety standards. Holes drilled closer than 2 inches create a higher risk of compromising the integrity of the joist, while drilling farther out, as in the case of 3 inches, may not always be necessary or practical, yet it does offer an added margin of safety.