Roofing flashings and roofing systems and photovoltaic roofing systems using the same

A roofing system comprising

• an underlying flashing element having a cross-sectional shape comprising a laterally- extending flange, the flange having an edge, a first end and a second end, the flashing element comprising a first edge structure disposed toward the first end of the edge, the first edge structure being selected from a return hem comprising a folded-over strip of material disposed over the top surface of the flange at the edge, and an edgewall with a return feature, the first edge structure having a first end disposed toward a first end of the edge and a second end disposed toward the second end of the edge, the underlying flashing element further comprising a second edge structure disposed toward the second end of the edge with respect to the first edge structure, the second edge structure being selected from an edgewall with a return feature and a return hem, the second edge structure having a first end disposed toward a first end of the edge and a second end disposed toward the second end of the edge, wherein the total thickness of the second edge structure at its second end is no greater than the interior thickness of the first edge structure at its first end;
• and
• an overlying flashing element having a cross-sectional shape comprising a laterally-extending flange, the flange having an edge, a first end and a second end, the flashing element comprising a first edge structure disposed toward the first end of the edge, the first edge structure being selected from a return hem and an edgewall with a return feature, the first edge structure having a first end disposed toward a first end of the edge and a second end disposed toward the second end of the edge, the overlying flashing element further comprising a second edge structure disposed toward the second end of the edge with respect to the first edge structure, the second edge structure being selected from an edgewall with a return feature and a return hem, the second edge structure having a first end disposed toward a first end of the edge and a second end disposed toward the second end of the edge, wherein the total thickness of the second edge structure at its second end is no greater than the interior thickness of the first edge structure at its first end,
• wherein the second end of the flange of the overlying flashing element overlaps the first end of the flange of the underlying flashing element, the second edge structure of the overlying flashing element nests under the folded-over strip of material of the return hem or the return feature of the first edge structure of the underlying flashing element, and the first edge structure of the flange of the underlying flashing element includes a discontinuity, at which the inside thickness of the first edge structure flange of the underlying flashing element transitions, in a direction going from the first end of the first edge structure flange, from substantially greater than the total thickness of the second edge structure to substantially less than the total thickness of the second edge structure.

A roofing system comprising

• an underlying flashing element having a cross-sectional shape comprising a vertically-extending feature, a flange extending laterally from the vertically-extending feature at the downward end thereof, the flange having an edge, a first end and a second end, the flashing element comprising a first edge structure disposed toward the first end of the edge, the first edge structure being selected from a return hem, and an edgewall without a return feature, and an edgewall with a return feature, the first edge structure having a first end disposed toward a first end of the edge and a second end disposed toward the second end of the edge, the flashing element further comprising a second edge structure disposed toward the second end of the edge with respect to the first edge structure, the second edge structure being selected from an edgewall without a return feature, an edgewall with a return feature and a return hem, the second edge structure having a first end disposed toward a first end of the edge and a second end disposed toward the second end of the edge, wherein the total width of the flange at the second end of the second edge structure is no greater than the interior width of the flange at the first end of the first edge structure;
• and
• an overlying flashing element having a cross-sectional shape comprising a vertically-extending feature, a flange extending laterally from the vertically-extending feature at the downward end thereof, the flange having an edge, a first end and a second end, the flashing element comprising a first edge structure disposed toward the first end of the edge, the first edge structure being selected from a return hem, and an edgewall without a return feature, and an edgewall with a return feature, the first edge structure having a first end disposed toward a first end of the edge and a second end disposed toward the second end of the edge, the flashing element further comprising a second edge structure disposed toward the second end of the edge with respect to the first edge structure, the second edge structure being selected from an edgewall without a return feature, an edgewall with a return feature and a return hem, the second edge structure having a first end disposed toward a first end of the edge and a second end disposed toward the second end of the edge, wherein the total width of the flange at the second end of the second edge structure is no greater than the interior width of the flange at the first end of the first edge structure;
• wherein
• the second end of the flange of the overlying flashing element overlaps the first end of the flange of the underlying flashing element,
• the second edge structure of the overlying flashing element nests within the first edge structure of the underlying flashing element, and
• the first edge structure of the underlying flashing element includes a discontinuity, at which the interior width of the flange at the first end of the underlying flashing element transitions, in a direction going from the first end of the flange, from substantially greater than the total width of the flange at the second end of the overlying flashing element to substantially less than the total width of the flange at the second end of the overlying flashing element.