Load Paths | Kaelan

Every force applied to a structure must find its way to the ground. Push on a wall, and that push travels through studs, through the sole plate, through the foundation, into the earth. The path it takes is the load path. Break that path anywhere, and the structure fails at the break.

Structural intuition is the ability to see these invisible rivers of force. Where does the weight of a roof go? Down through rafters to bearing walls, through those walls to the foundation. What happens when you cut a hole for a window? The load that wall carried must now go around the opening — hence the header beam above, transferring weight to the trimmer studs on each side.

Most structural failures occur at discontinuities: where load paths change direction, where materials meet, where someone cut through something load-bearing without providing an alternate route. The deck that collapsed had its ledger board pulling away from the house. The balcony that fell had corroded connectors hidden behind stucco. The loads were always there; the path just finally gave out.

Good builders think in terms of continuous load paths from roof to foundation. Every connection must be designed to transfer not just gravity loads (pushing down) but also lateral loads (wind, earthquakes pushing sideways) and uplift (wind trying to lift the roof off). Hurricane straps, hold-downs, shear walls — hardware that makes invisible force paths explicit.

Intuition develops from seeing structures exposed. Framing before drywall. Demolition revealing what held what. Old buildings whose skin has worn away. You start to feel where the forces want to go, and where they’re being asked to do something difficult.

This is why experienced builders can look at a plan and spot problems — that beam is undersized, that cantilever is too long, that opening needs a bigger header. They’re tracing load paths in their minds, checking that every force has a credible route to ground.