Which method of spacing for studs is typically not acceptable in let-in-bracing?

In let-in-bracing applications, the spacing of studs is crucial for maintaining the structural integrity and effective load distribution of the wall system. The standard spacing for studs is often 16 inches on center (O.C.) or less, which ensures adequate support and bracing effectiveness.

Spacing studs at 18 inches O.C. can still be acceptable in certain conditions, as it may provide sufficient support depending on the material and load requirements. However, moving to 24 inches O.C. often raises concerns regarding the stability and strength provided by the let-in bracing, especially when considering lateral forces and the need for rigidity in the wall assembly.

30 inches O.C. is generally deemed too far apart for stud spacing in typical let-in-bracing configurations, as it can severely compromise the wall's ability to resist racking forces, which are critical for maintaining the structural soundness of the building. This spacing would not provide the right amount of resistance needed to counteract lateral loads, making it the least acceptable option for this type of bracing. Hence, spacing studs at 30 inches O.C. is typically not acceptable in let-in-bracing scenarios.