Why Vermont Roofed Its Bridges

The covered bridge is now pure romance, the stuff of paintings and wedding photos. But the roof that gives it its charm was never about beauty. It was a practical solution to a stubborn engineering problem: how to keep a wooden bridge from rotting away.

The answer lay in shelter. An exposed timber bridge, soaked by every rain and snow, might last only a decade or two before its trusses rotted and failed. Cover it with a roof and walls, keeping the structural wood dry, and the same bridge could stand for a century or more. The builders weren't being sentimental; they were being economical.

The distinctive look was a byproduct of that logic, though it quickly became beloved in its own right. Different builders favored different truss designs, hidden inside the walls, each a small feat of the carpenter's craft. Today Vermont works hard to preserve its surviving covered bridges, prizing exactly the picturesque quality their builders never intended. It's a fitting irony: the most photographed structures in the state owe their existence to a very unglamorous desire to keep the rain off the wood.