Sawtooth (shed) roof

The toothed roof of factories: a series of asymmetric pitches, one opaque and one glazed, repeated. The glazing, all facing north, brings in a constant, diffuse daylight with no direct sun, glare or overheating; the opaque pitch screens the south. It is the roof born with the factory, to light large spaces evenly from above — demanding only careful valleys and maintenance.

A sawtooth roof is the toothed roof of factories: a series of asymmetric pitches, one opaque and one glazed, repeated. The glazing, all facing north, brings in a constant, diffuse daylight, with no direct sun. It is the roof born with the factory, to light large spaces from above.

The principle is simple and brilliant: by facing the glazing north, the space receives the light of the sky — soft, even, present all day — but never the direct sun, which brings glare and overheating. The opaque pitch, facing south, acts as a screen. The result is quality daylight over large areas, with less artificial light.

Each tooth is a small structure: a truss or beam (steel, sometimes glulam) carrying the insulated opaque pitch and the glazing. Between one tooth and the next runs a valley — an internal gutter — collecting the water from all the pitches. It is the critical point: sized and inspectable, because a valley that clogs floods the roof.

The many joints between glass, frames and covering must be sealed with care; condensation on the glazing is handled with double glazing and ventilation. Shading or selective glass can be added if the gains must be controlled. Glazing and valleys need access and planned maintenance, because a sawtooth roof is beautiful when lit but demanding to keep.