Roof element

A first roof element comprising:

• (1) a plate material having first and second side edges, an upper edge and a lower edge;
• the plate material forming the roof element with at least an upper surface, a lower surface, a first step disposed between the upper surface and the lower surface and extending transversely therefrom, and a second step disposed at an end of the lower surface and extending transversely therefrom;
• (2) wherein each of the upper and lower surfaces extends in a lengthwise direction that is substantially parallel to that of the upper and lower edges and in a widthwise direction that is substantially parallel to that of the first and second side edges;
• (3) wherein the second step comprises a first step portion that extends downwardly from the lower surface, a second step portion that extends upwardly toward the lower surface and a round bend disposed between the first step portion and the second step portion, the second step portion being disposed underneath the lower surface and comprising the lower edge;
• and
• (4) wherein the plate material has a profile in the shape of a wave in a height direction when viewed from a front thereof and is constructed and arranged such that the first roof element is disposable in an overlapping arrangement with a second roof element of the same shape wherein (a) (i) the lower surface of the first roof element lies atop and contacts the upper surface of the second roof element, (ii) the first step portion of the second step of the first roof element overlaps a surface of the first step of the second roof element and is uniformly proximal to the surface of the first step of the second roof element along an entire width of the overlap, (iii) the second step portion of the second step of the first roof element is sandwiched between the first step portion of the second step of the first roof element and the surface of the first step of the second roof element and (iv) the lower edge of the first roof element is disposed beneath the lower surface of the first roof element, whereby in the overlapping arrangement the lower edge of the first roof element is protected from the environment and movement between the first and second roof elements is inhibited in a first direction, and (b) the waves of the respective profiles of the first and second roof elements are aligned such that, in the overlapping arrangement, movement between the first and second roof elements is inhibited in a second direction that is different from the first direction.