Timber notches that quietly fail domestic floors

Notches at the bearing of a domestic joist are a frequent source of call-backs. Cutting too deep at mid-span for services is worse. During our timber workshop we walk a Harlow terrace, photograph existing notches, and redraw the allowed zones on A3.

Rules of thumb from textbooks are a starting point; the measured walk shows how plumbers and electricians actually route pipes. Students leave with a one-page detail sheet they can keep in a site folder — hanger types, notch limits, and a note on when to ask for a structural review instead of guessing.