A lintel system for supporting masonry blocks above an opening in a structure includes a lintel configured to span a width of the opening. The lintel includes a single spanning member having a top edge, a bottom edge, and a side face extending between the top and bottom edge. Supports are disposed at longitudinal ends of the single plate member. A stiffener is attached to the lintel for reinforcing the lintel. The stiffener extends in opposed relation to the side face along at least a portion of the side face.

A formwork for constructing an arched structure comprises a first end panel and a second end panel. A plurality of longitudinal members extends between the first end panel and the second end panel. The longitudinal members are arranged in an arched formation and the longitudinal members slope between the first end panel and the second end panel. The formwork may have rollers disposed along lengths of the longitudinal members.

An apparatus includes an arch-support system configured to support an archway above a work surface during construction of the archway. A rail assembly is configured to selectively receive and support the arch-support system in such a way that the rail assembly, in use, supports the arch-support system once the rail assembly selectively receives the arch-support system.

A formwork for constructing an arched structure comprises a first end panel and a second end panel. A plurality of longitudinal members extends between the first end panel and the second end panel. The longitudinal members are arranged in an arched formation and the longitudinal members slope between the first end panel and the second end panel. The formwork may have rollers disposed along lengths of the longitudinal members.

Structural plates and methods of constructing arch-shaped structures using structural plates. Structural plates may include a combination of features including: an outer structural plate having adjacent circumferential apertures respectively spaced nominally greater than adjacent circumferential apertures of an inner structural plate; and the outer structural plate having nominally 5 enlarged or differently shaped circumferential apertures (as compared to circumferential apertures of the inner structural plate) such that the embodiment structural plates may be radiused to a variety of different radii while achieving desirable overlapping alignment of apertures along overlapping circumferential edges for receiving fasteners therein. Joiner plates may be provided for interconnecting structural plates along transverse edges in a non-overlapping arrangement, 10 thereby reducing the quantity of structural plate material that otherwise would be needed for a given circumferential length of the arch-shaped structure.

A formwork for constructing an arched structure comprises a first end panel and a second end panel. A plurality of longitudinal members extends between the first end panel and the second end panel. The longitudinal members are arranged in an arched formation and the longitudinal members slope between the first end panel and the second end panel. The formwork may have rollers disposed along lengths of the longitudinal members.