Worked examples, fundamentals and code notes for engineers and students running early load takedowns. Practical, transparent, and tied to how the tool actually works.
Tributary area is the single idea that turns a floor plan into column reactions. Here is the clean mental model, the midline method, and the cases where sketching it by hand quietly fails.
A gym floor carries heavy racks, dropped weights and people jumping in time. The static load is only the start; impact and rhythm matter as much.
Turning an office into flats, a shop into a gym or a house into a clinic changes the imposed load. Here is how to rerun the takedown and what to check.
Water on a flat roof is a load that grows as the roof deflects. Each 25 mm of depth adds about 0.25 kPa, and the feedback loop is the real danger.
Wind piles snow against anything that sticks up from a roof. The drift can carry three or four times the uniform snow load, over a few metres.
A barrier load is a line load applied sideways at the top of the guard, and the real design problem is getting it down into the slab edge.
A hospital floor is a set of very different zones, not one rate. Scanner masses, shielding, vibration criteria, and the loads hanging from the soffit.
A lift touches the structure in three places: the head, the rail brackets, and the pit. Dynamic factors, shaft walls, and why pits float.
Shelved paper is heavier per square metre than almost anything else a building holds. Static stacks, mobile shelving on rails, and why deflection governs.
Assembly floors are where people really do reach the code value. Unreduced rates, synchronised movement, barrier horizontal loads, stages and stairs.
