What is the maximum diameter hole that may be drilled in a 2 inch by 12 inch joist?

In determining the maximum diameter hole that may be drilled in a 2 inch by 12 inch joist, one must refer to the guidelines specified in the building codes pertaining to framing members. Generally, for solid sawn lumber joists, the diameter of holes that may be bored is often specified as a percentage of the member's depth.

For a 2 inch by 12 inch joist, the critical measurement is the depth, which is 12 inches. Building codes often allow holes that do not exceed one-third of the joist’s depth. Therefore, in this case, one-third of 12 inches is 4 inches. However, the maximum size must also consider the width of the joist, since the hole should not exceed the actual dimensions of the joist itself.

In this scenario, if a hole up to 4 inches in diameter is too large for the width of the joist (which is 2 inches), one must refer to common practice and code allowances for drilling holes. The commonly accepted guideline is that a hole can be drilled up to 3/4 of the width or 1 inch in diameter, as long as it meets the depth requirement.

However, in recognizing that the options provided offer sizes larger than