What is the minimum header size for a non-bearing wall with a 7 ft 6 in opening?

The minimum header size for a non-bearing wall with a 7 ft 6 in opening requires careful consideration of load distribution and structural integrity. For a non-bearing wall, the primary function of the header is to support the weight of the wall above the opening, not to carry any additional loads from the structure.

A single 2x4 is typically sufficient for a non-bearing wall when spanning an opening of this size because non-bearing walls generally don't carry significant structural loads compared to bearing walls. The 2x4 header can effectively support the lightweight loads attributed to a wall, as the non-bearing wall does not support the structural framework above.

Choosing larger headers, like a 2x6 or multiple 2x4s, is typically unnecessary for openings of this size in non-bearing applications, as they might exceed the structural requirements and add unwanted weight or material costs. Therefore, the standard practice in residential construction for this type of opening aligns with using a single 2x4 header.