No. 2 Grade (Lumber)
The standard structural lumber grade for residential framing. Permits moderate knots and characteristics while maintaining adequate strength for most floor, wall, and roof framing applications.
In Detail
No. 2 is the default grade specified in IRC prescriptive span tables and is the most commonly stocked grade at lumber yards. It provides roughly 80–85% of Select Structural design values at 40–50% lower cost. Almost all residential framing — studs, joists, rafters, headers — uses No.2 or better. The "or better" designation means any grade equal to or above No.2 (No.1, Select Structural) is acceptable.