Bendable 'Z' head flashing

Abstract

Bendable ‘Z’ Head flashing is used in conjunction with other building materials above arched openings or components in the exterior walls of buildings to protect the building structure from water intrusion. Pre-formed notches in the vertically mounting flange allow the horizontal portion of the flashing to conform to arched or curved openings, the head of arch top window or door frames, and arched trim.

Description

CROSS REFERENCE TO RELATED APPLICATIONS AND DISCOSURES[0001]This non-provisional utility patent application claims the benefit of provisional patent application No. 60 / 756,646 filed Jan, 6, 2006, and disclosure document number 545447.BACKGROUND OF THE INVENTION[0002]The present invention relates to architectural stock flashing material used for weatherproofing the head of arch top windows and doors, and arched trim on the exterior buildings in building construction.[0003]In construction it is customary to install head flashing at the tops of openings in exterior walls, during the installation of windows, doors, and adjacent siding and trim. Uniform building codes require exterior openings exposed to the weather shall be flashed in such a manner to make them weatherproof. The intent is to keep moisture on the surface of building paper from wetting structural elements or entering the exterior wall cavity. Various flexible flashings, water resistant papers and sealants are utilized to ...

AI Technical Summary

Benefits of technology

[0010]For the length of the bendable ‘Z’ head flashing, the back vertical mounting flange has equal spaced holes near the top free edge for fastener locations, and equal spaced notches extending from the free edge towards the horizontal section. Each notch terminates in a circular void in proximity to the horizontal section, but at a distance to provide a small section of uninterrupted vertical flange adjacent to the horizontal flange. The diameter of the circular void is larger than the width of the notch, to distribute tension stresses at the base of the flat vertical mounting flange over a larger circle circumference and reduce the possibility of cracking and buckling.

[0011]When the flashing is curved during installation, the notches will widen adjacent to the upper free edge of the vertical mounting flange, and the circular voids will deform to an oval shape. Because of the flexible composition, the horizontal portion or leg of the present invention can readily conform to a radius, and small effective dimensional areas of both vertical flanges can absorb tension and compression stress without undo deformation.

[0012]The present invention is installed in sequence with the building wall moisture barrier, arched doors, windows or adjacent arched trim, before installing exterior siding. Building structural framing, siding and trim around windows and doors is protected from rainwater or other moisture by bendable ‘Z’ head flashing in conjunction with other building materials. Bendable ‘Z’ head flashing protects the joint between dissimilar construction components and directs moisture outward away from building moisture barriers.

Problems solved by technology

With arched or curved top doors and windows, or curved siding trim, ‘Z’ flashing does not easily conform to a radius, with the legs or flanges perpendicular to the curved surface resistant to bending because of the inherent geometry.

Because of the resistance to bending, the installation of head flashing along curved surfaces is difficult, if attempted at all.

Some sheet metal fabricators have the capacity to custom rolled “Z’ flashing to the exact radius required, which is costly and requires planning ahead.

For most installations of arched top windows, doors and curved trim there is not a satisfactory solution.

It is also inefficient and difficult for field tradespersons to make closed end cuts of uniform length or spacing.

Poorly made cuts tend to further lengthen along the cut or induce cracking in the flashing flange, while inaccurately spaced cuts do not permit a uniform radius.

With field modified metal flashing, bending can also result in kinking or distortion in legs of the flashing.

When a repair is made it can be labor intensive and ineffective.

Slits made into the total height of the flashing back leg are difficult to properly repair with flexible sheet flashing, as the sheet material must be carefully placed into the curving corner formed between the back vertical leg and horizontal leg of the flashing, and there is insufficient lap distance between the self-adhering flexible sheet flashing and the notch made in the underlying ‘Z’ flashing.

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