Why does an inspector note a header that has been cut for a duct or a pipe?

A header spans an opening and carries the load that the interrupted studs would otherwise have taken directly to the plate — floor loads, roof loads, and everything above. It is sized for that span and that load, so it has no surplus material to give away. Cutting it for a duct or a pipe removes section exactly where bending stress is highest, and unlike a joist there is no permitted-hole zone because the member is short, heavily loaded and often built up from multiple plies. The finding matters in interior walls as well as exterior ones, since interior bearing walls carry floor and roof loads too. As with any structural alteration, the inspector reports the penetration and refers evaluation, because whether the remaining section is adequate is a calculation.

A header carries the load over an opening and is sized specifically for it, so cutting it removes material the member needs. Whether the remaining section is adequate requires structural evaluation.

Headers span wall openings and transfer loads to trimmer studs and down to the foundation. They are sized for span and load and have no permitted penetration zone, so notching or drilling requires engineered evaluation.

Headers Have No Spare Wood. Sized for the span, loaded to the span — there is no middle third to drill through.

Look above the opening for sagging, cracked finishes at the corners or a door that has begun to bind. Those are the corroborating symptoms.

• •Applying joist hole rules to headers
• •Limiting the concern to exterior walls
• •Judging adequacy rather than referring the penetration