A parallel-ridged roof is any roof whose shape is folded into multiple ridgelines, which do not meet each other and do not line up in a continuous line. The ridges do not have to be truly parallel; they may fan out as radii from a common or imaginary starting point, or in rare cases may be juxtaposed at odd angles to each other (as long as they do not meet and cannot easily be construed as a continuous straight or bent line).

The ridges need not be geometrically parallel. They can fan outward or lie at different angles while remaining separate.

A cross-ridged roof has an intersection or fork. A single ridge that merely bends is also excluded from this multiple, separate-ridge form.