Planning
First establish services, ground, water, working space, support and weather window. Design structure and connections for the location, span and earth load. Prepare components outside the excavation wherever possible.
Emergency preparedness · 18 min
The critical period is construction: unsupported soil can collapse suddenly, timber can fail under earth load and water can fill the excavation. The lesson therefore defines a safe sequence but deliberately gives no universal spans or beam sizes.
Decision compass
Four questions lead from observation to a clear, safer action.
What needs to be clarified now?
Remember: Observe → assess → choose a safer option → act.

Excavation, support, timber frame and roof are treated as designed temporary stages.
First establish services, ground, water, working space, support and weather window. Design structure and connections for the location, span and earth load. Prepare components outside the excavation wherever possible.
Nobody works beneath loose soil faces or an incompletely supported roof. Before each additional layer, a competent responsible person checks frames, bracing, connections and deformation. Rain or movement stops the work.
During use, visibly inspect timber moisture, decay, fasteners, settlement and roof deformation. Cracking sounds, new movement, water or loose soil require immediate evacuation and closure.
Decision training
Correct: B. Photographs, plans, specialist checks and a functional test show whether the proposed solution works safely at the actual site.