Sub-rafter with vertical slots and roof system for a curved roof

Abstract

A sub-rafter configured to substantially conform to a roof that is curved between an eave and a ridge. The sub-rafter comprises a bottom flange, a top wall, a web extending between the bottom flange and the top wall, and a slot extending through the top wall and at least partially into the web. The slot comprises a lower end positioned in the web and spaced a predetermined distance from the bottom flange. A top band may be joined to the top wall after the sub-rafter is joined to existing structural members. A roofing system of the present disclosure comprises: a sub-rafter attached to a structural member of an existing curved roof, a top band joined to a top wall of the sub-rafter, a cross-member joined to the sub-rafter, and a new roof structure attached to the cross-member. In embodiments, the new roof structure comprises metal panels.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority under 35 U.S.C. § 119 (e) to U.S. Provisional Patent Application Ser. No. 63 / 683,649 filed Aug. 15, 2024, which is incorporated herein in its entirety by reference.FIELD

[0002] The present disclosure relates to devices, systems and methods for retrofitting roofs, including a sub-rafter configured to bend to substantially match the curvature of an existing structure, including the radius of curvature of an existing roof structure, such that the sub-rafter may be secured to the existing purlins, joists, girders, beams or other structural members of a building, the sub-rafter typically running upslope and approximately perpendicular to these members. Structural cross-members, such as sub-purlins or hat channels, or other cross-members, are then attached to the sub-rafters, typically running parallel to the roof eave line and approximately perpendicular to the sub-rafters and serve as the primary attachment points for a new metal roof or other roofing material.BACKGROUND

[0003] Sometimes it is necessary to replace a metal roof (or a roof formed of other materials) of a building when the metal roof has reached the end of its useful life, is damaged, inadequate, or does not comply with new or revised building codes. For example, existing metal roofs that do not comply with wind uplift codes, snow load requirements, and / or other requirements might need to be replaced or upgraded. One option is to remove the existing metal roof and replace it with a new stronger roof formed of metal or other materials. However, removing and replacing the existing metal roof is detrimental and costly because the building must be vacated, businesses occupying the building may need to be relocated or the building may need to be closed while the roof is removed and replaced. Additionally, the existing metal roof must be transported away and disposed of properly after it is removed from an existing structure. In addition, removing the existing metal roof is labor intensive, frequently requiring the installation of additional structural members and / or necessitating repairs to other components due to incidental damages associated with its removal.

[0004] Alternatively, an existing metal roof can be retrofitted by installing a new metal roof system over the existing metal roof. Retrofitting the existing metal roof can typically be done without vacating the building, which beneficially reduces the impact or disruption to occupants. Further, retrofitting a roof by installing a new roof system over the existing metal roof typically provides significant saving of time, labor, materials and the overall associated costs when compared to removing and replacing an existing metal roof.

[0005] Known systems, however, are not compatible for use with an existing metal roof that is curved between the eave and the ridge.SUMMARY

[0006] Accordingly, there is a need for devices, systems and methods of installing a new roof over an existing curved roof.

[0007] In one aspect of the present disclosure is a curvable sub-rafter configured for installation on a roof of a building, the roof being curved between an eave and a ridge, and the curvable sub-rafter comprising: (1) a bottom flange; (2) a top wall spaced from the bottom flange; (3) a web between the bottom flange and the top wall; and (4) a slot extending through the top wall and at least partially through the web toward the bottom flange.

[0008] In one or more aspects of the sub-rafter, the closed end of the slot is spaced from the bottom flange.

[0009] In one or more aspects of the sub-rafter according to present disclosure, the bottom flange is conformable to a curvature of the roof between an eave and a ridge.

[0010] In one or more embodiments, at least the bottom flange is at least partially conformable to the curvature of the roof.

[0011] In embodiments, at least one of the bottom flange, the web and the top wall are at least partially conformable to a curvature of the roof.

[0012] In some embodiments, the top wall is planar when the curvable sub-rafter is in an initial state and is generally linear, such as before the curvable sub-rafter is affixed to the curved roof.

[0013] The top wall is not planar when the curvable sub-rafter is in a second state that is not linear, such as when the curvable sub-rafter is in a position of use affixed to the curved roof.

[0014] In some embodiments the bottom flange is planar when the curvable sub-rafter is in an initial state and is generally linear, wherein the bottom flange is not planar when the curvable sub-rafter is in a second state that is not linear, such as when the curvable sub-rafter is in a position of use affixed to the curved roof.

[0015] In some embodiments, the curvable sub-rafter includes one or more of the previous embodiments and the top wall is approximately parallel to the bottom flange when the curvable sub-rafter is in the initial state, and wherein the top wall is not parallel to the bottom flange when the curvable sub-rafter is in the second state, such as when the curvable sub-rafter is in a position of use affixed to the curved roof.

[0016] In some embodiments, the curvable sub-rafter includes one or more of the previous embodiments and the web is oriented approximately perpendicular to one or more of the top wall and the bottom flange.

[0017] In some embodiments, the curvable sub-rafter includes one or more of the previous embodiments and: (1) the web is a first web that extends from a first long edge of the top wall; and (2) the bottom flange is a first bottom flange that extends from the first web; and the curvable sub-rafter further comprises: (3) a second web extending from a second long edge of the top wall, wherein the slot extends into the first and second webs; and (4) a second bottom flange that extends from the second web.

[0018] In some embodiments, the sub-rafter according to the present disclosure comprises a sub-rafter wherein at least one of the first and second bottom flanges and the first and second webs are conformable to the curvature of the roof between the eave and the ridge.

[0019] In some embodiments, the curvable sub-rafter includes one or more of the previous embodiments and the closed end of the slot is rounded.

[0020] In some embodiments, the curvable sub-rafter includes one or more of the previous embodiments and the closed end of the slot has a diameter that is greater than a width of the slot when the curvable sub-rafter is in the initial state.

[0021] In some embodiments, the curvable sub-rafter includes one or more of the previous embodiments and the curvable sub-rafter comprises a metallic material with a substantially uniform thickness.

[0022] In some embodiments, the curvable sub-rafter includes one or more of the previous embodiments and the curvable sub-rafter is a composite material comprising carbon fiber, wherein the composite material has a substantially uniform thickness.

[0023] In some embodiments, the curvable sub-rafter includes one or more of the previous embodiments and the slot is oriented approximately perpendicular to a reference plane defined by the top wall when the curvable sub-rafter is in the initial state.

[0024] In some embodiments, the curvable sub-rafter includes one or more of the previous embodiments and the curvable sub-rafter further comprises a top band affixed to the top wall after the curvable sub-rafter is bent and the curvable sub-rafter is in the second state.

[0025] In some embodiments, the curvable sub-rafter includes one or more of the previous embodiments and the top band extends from a first portion of the top wall on a first side of the slot, across the slot, and to a second portion of the top wall on a second side of the slot.

[0026] In some embodiments, the curvable sub-rafter includes one or more of the previous embodiments and the top band is affixed to the top wall with: (a) a first fastener that extends through the top band and the first portion of the top wall; and (b) a second fastener that extends through the top band and the second portion of the top wall.

[0027] In some embodiments, the curvable sub-rafter includes one or more of the previous embodiments and the top band is formed of a metallic material or a composite material.

[0028] Optionally, the top band has a first thickness that is substantially uniform, and the curvable sub-rafter has a second thickness that is less than or equal to the first thickness.

[0029] In at least one embodiment, the first thickness is substantially equal to the second thickness.

[0030] In some embodiments, the top wall of the sub-rafter has a first length when measured in the second state, and the top band has a second length, the second length being approximately equal to the first length.

[0031] Another aspect of the present disclosure is a roofing system affixed to a roof that is curved between an cave and a ridge or peak of a building, comprising: (1) a curvable sub-rafter positioned on an exterior surface of the roof, wherein the curvable sub-rafter is attached to a structural member of the roof, the structural member being under the exterior surface, the curvable sub-rafter extending between the cave and the ridge and oriented approximately perpendicular to the structural member of the roof, wherein the curvable sub-rafter comprises: (a) a bottom flange that is curved between the cave and the ridge; (b) a top wall spaced from the bottom flange, the top wall curved between the cave and the ridge; (c) a web extending between the bottom flange and the top wall; and (d) a slot extending through the top wall and into the web; (2) a top band fastened to the top wall, the top band curved between the cave and the ridge, wherein: (a) a first mechanical fastener extends through the top band and through a first portion of the top wall on a first side of the slot; and (b) a second mechanical fastener extends through the top band and through a second portion of the top wall on second first side of the slot such that the top band bridges the slot; (3) a cross-member positioned on the top band and attached to the curvable sub-rafter, the cross-member oriented approximately perpendicular to the curvable sub-rafter; and (4) a new roof structure attached to the cross-member.

[0032] In some embodiments the cross-member is aligned vertically with the structural member of the roof.

[0033] In some embodiments, the roofing system includes one or more of the previous embodiments and further comprises a second cross-member positioned on the top band and attached to the curvable sub-rafter, the second cross-member approximately parallel to the first cross-member, wherein the second cross-member is positioned between two structural members of the roof.

[0034] In some embodiments, the roofing system includes one or more of the previous embodiments and a closed lower-end of the slot is generally circular.

[0035] In some embodiments, the roofing system includes one or more of the previous embodiments and: (a) a lower portion of the slot proximate to the closed lower-end has a first width measured between two linear edges of the slot, and (b) an upper portion of the slot proximate to the top wall has a second width measured between the two linear edges of the slot, the second width being greater than the first width.

[0036] Another aspect of the present disclosure is a method of forming a curvable sub-rafter, comprising: (1) providing a structural sheet material that extends along a longitudinal axis; (2) forming at least two slots in the structural sheet material, the slots spaced along the longitudinal axis and oriented approximately perpendicular to the longitudinal axis; (3) cutting the structural sheet material to a predetermined length; and (4) folding the structural sheet material at least three times along three lines approximately parallel to the longitudinal axis to form the curvable sub-rafter comprising: (a) a bottom flange; (b) a top wall; (c) a web extending from the bottom flange to the top wall; and (d) the slots extending through the top wall and at least partially through the web toward the bottom flange, wherein a closed end of each slot is spaced from the bottom flange.

[0037] In one or more embodiment, the structural sheet material has a first edge and a second edge that extend parallel to the longitudinal axis, and the at least two slots extend to the first edge.

[0038] Alternatively, in other embodiments, the at least two slots include ends that are spaced from the first edge and the second edge.

[0039] In some embodiments, the structural sheet material comprises one of a metal, a composite material, and a plastic.

[0040] In one or more embodiments, the method of forming a curvable sub-rafter according to the present disclosure comprises providing a sheet comprising a structural material that extends along a longitudinal axis.

[0041] In embodiments, the method further comprises forming a plurality of spaced apart slots along the structural sheet material.

[0042] In one or more embodiments, the method comprises forming spaced apart slots along the structural sheet material, the slots being oriented approximately perpendicular to the longitudinal axis.

[0043] In embodiments, the method comprises cutting the structural sheet material to a predetermined length.

[0044] In one or more embodiments according to the present disclosure, the method comprises folding the structural sheet material to define the bottom flange, the web and the top wall.

[0045] In at least one embodiment, the method comprises folding the structural sheet material in at least three locations or fold lines that are approximately parallel to the longitudinal axis of the sub-rafter.

[0046] In embodiments, the method optionally comprises folding the structural sheet material in four locations or fold lines to define two bottom flanges, two webs and the top wall.

[0047] In one or more embodiments of the method according to the present disclosure, the resulting sub-rafter comprises one or two bottom flanges, one or two webs and the top wall.

[0048] In embodiments of the method, the web(s) extends from the bottom flange(s) to the top wall.

[0049] In one or more embodiments of the method, the resulting sub-rafter comprises slots that extend through the top wall and at least partially through the web toward the bottom flange.

[0050] In embodiments of the method, a closed end of each slot is spaced apart from the bottom flange.

[0051] In one or more embodiments of the method, the resulting sub-rafter comprises the web with an area between the slot and the bottom flange that can bend, i.e., expand or contract, or otherwise act as a hinge such that the sub-rafter can conform to the geometry of an existing roof that is curved between an cave and a ridge or peak.

[0052] The Summary is neither intended nor should it be construed as being representative of the full extent and scope of the present disclosure. The present disclosure is set forth in various levels of detail in the Summary as well as in the attached drawings and the Detailed Description and no limitation as to the scope of the present disclosure is intended by either the inclusion or non-inclusion of elements, components, etc. in this Summary. Additional aspects of the present disclosure will become clearer from the Detailed Description, particularly when taken together with the drawings.

[0053] As used herein, the phrase “curved roof” means a roof with an exterior surface that is curved between a low point (such as an cave or valley) and a high point (such as a ridge or peak). The exterior surface of the curved roof has a shape similar to a section of a cylinder. For example, a cross-section of a curved roof taken along its pitch will have an exterior surface that is curved, or which defines an arc.

[0054] As used herein, the phrase “flat roof” means a roof with an exterior surface that is generally planar between a low point and a high point. For example, the pitch of a flat roof is substantially constant between the low point and the high point. In another example, a cross section of a flat roof taken along its pitch will have an exterior surface that is substantially linear.

[0055] As used herein, the term “sub-rafter” means a structural member that attaches to and spans between existing purlins, joists, girders, beams or other structural members of a roof or a building structure. A sub-rafter typically runs upslope (i.e., parallel to the slope or pitch between an eave line and a ridge line of the roof) and perpendicular to the existing purlins, joists and other structural members (which typically run parallel to the cave line). After a sub-rafter is positioned on an existing roof and secured to structural members of the existing roof, new structural cross-members (such as sub-purlins or hat channels) are attached to the sub-rafters and serve as the primary attachment points for the new roof material, such as new metal panels. Sub-rafters are necessary because they allow the new structural members to be attached at a different spacing than the spacing of existing structural members of the existing roof.

[0056] Although the curvable sub-rafter is generally described herein for use on a curved roof, those of skill in the art will appreciate that the curvable sub-rafter of all embodiments and aspects of the present disclosure may be affixed to (and used with) and curved surface of a building. For example, the curvable sub-rafter may be affixed to a curved wall, a curved ceiling, a curved fascia, and other curved structures whether inside or outside of a building.

[0057] The phrases “at least one,”“one or more,” and “and / or,” as used herein, are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions “at least one of A, B and C,”“at least one of A, B, or C,”“one or more of A, B, and C,”“one or more of A, B, or C,” and “A, B, and / or C” means A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B and C together.

[0058] The term “a” or “an” entity, as used herein, refers to one or more of that entity. As such, the terms “a” (or “an”), “one or more” and “at least one” can be used interchangeably herein.

[0059] Unless otherwise indicated, all numbers expressing quantities, dimensions, conditions, ratios, ranges, and so forth used in the specification and claims are to be understood as being modified in all instances by the term “about” or “approximately”. When used with a number or a range, the terms “about” and “approximately” indicate the number or range may be “a little above” or “a little below” the endpoint with a degree of flexibility as would be generally recognized by those skilled in the art. Further, the terms “about” and “approximately” may include the exact endpoint, unless specifically stated otherwise. Accordingly, unless otherwise indicated, all numbers expressing quantities, dimensions, conditions, ratios, angles, ranges, and so forth used in the specification and claims may be increased or decreased by approximately 5% to achieve satisfactory results. Additionally, where the meaning of the terms “about” or “approximately” as used herein would not otherwise be apparent to one of ordinary skill in the art, the terms “about” and “approximately” should be interpreted as meaning within plus or minus 10% of the stated value.

[0060] The term “parallel” means two objects are oriented at an angle within plus or minus 0° to 5° unless otherwise indicated. Similarly, the term “perpendicular” means two objects are oriented at angle of from 85° to 95° unless otherwise indicated.

[0061] Unless otherwise indicated, the term “substantially” indicates a difference of from 0% to 5% of the stated value is acceptable.

[0062] All ranges described herein may be reduced to any sub-range or portion of the range, or to any value within the range without deviating from the invention. For example, the range “5 to 55” includes, but is not limited to, the sub-ranges “5 to 20” as well as “17 to 54.”

[0063] The use of “including,”“comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Accordingly, the terms “including,”“comprising,” or “having” and variations thereof can be used interchangeably herein.

[0064] It shall be understood that the term “means” as used herein shall be given its broadest possible interpretation in accordance with 35 U.S.C., Section 112 (f). Accordingly, a claim incorporating the term “means” shall cover all structures, materials, or acts set forth herein, and all of the equivalents thereof. Further, the structures, materials, or acts and the equivalents thereof shall include all those described in the Summary, Brief Description of the Drawings, Detailed Description, Abstract, and Claims themselves.BRIEF DESCRIPTION OF THE DRAWINGS

[0065] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the disclosed system and together with the general description of the disclosure given above and the detailed description of the drawings given below, explain the principles of the disclosed system(s) and device(s).

[0066] FIG. 1A is a schematic illustration of a prior art roofing system for installing a new metal roof over an existing roof that is flat or in a constant plane or angle;

[0067] FIG. 2A is a front elevation view of a curvable sub-rafter according to embodiments of the present disclosure having a “Z” or “Zee” shape;

[0068] FIG. 2B is a side elevation view of the curvable sub-rafter of FIG. 2A;

[0069] FIG. 2C is a top plan view of a flat sheet of a structural material used to form the curvable sub-rafter of FIG. 2A;

[0070] FIG. 3A is a front elevation view of a curvable sub-rafter according to other embodiments of the present disclosure;

[0071] FIG. 3B is a perspective view of the curvable sub-rafter of FIG. 3A;

[0072] FIG. 3C is an image of the curvable sub-rafter of FIG. 3A shown after bending of the curvable sub-rafter;

[0073] FIG. 3D is a top plan view of a flat sheet of a structural material used to form the curvable sub-rafter of FIG. 3A;

[0074] FIG. 4A is a side elevation view of the curvable sub-rafter of FIG. 3A with a top band attached to a top wall of the curvable sub-rafter;

[0075] FIG. 4B is a cross-sectional elevation view of the curvable sub-rafter and top band of FIG. 4A taken along line 4B-4B of FIG. 4A;

[0076] FIG. 4C is a perspective view of the curvable sub-rafter and top band of FIG. 4A;

[0077] FIG. 4D is a side elevation view of the curvable sub-rafter and top band of FIG. 4A shown in a bent state;

[0078] FIG. 4E is an image of a curvable sub-rafter and top band shown after bending of the curvable sub-rafter;

[0079] FIG. 5A is a schematic illustration of a roofing system according to embodiments of the present disclosure for installing a new roof over a curved existing metal roof of a building;

[0080] FIG. 5B is a detailed view of a portion of FIG. 5A;

[0081] FIG. 5C is a perspective view of a notched sub-purlin according to embodiments of the present disclosure; and

[0082] FIG. 5D is cross section elevation view of a hat channel according to embodiments of the present disclosure;

[0083] FIG. 6 is an image of components of a roofing system according to embodiments of the present disclosure positioned on an existing metal roof that is curved; and

[0084] FIG. 7 is a diagrammatic representation of one or more embodiments of the method of forming a sub-rafter according to the present disclosure.

[0085] The drawings are not necessarily (but may be) to scale. In certain instances, details that are not necessary for an understanding of the disclosure or that render other details difficult to perceive may have been omitted. It should be understood, of course, that the disclosure is not necessarily limited to the embodiments illustrated herein. As will be appreciated, other embodiments are possible using, alone or in combination, one or more of the features set forth above or described below. For example, it is contemplated that various features and devices shown and / or described with respect to one embodiment may be combined with or substituted for features or devices of other embodiments regardless of whether or not such a combination or substitution is specifically shown or described herein.

[0086] The following is a listing of components according to various embodiments of the present disclosure, and as shown in the drawings:NumberComponent 2AExisting roof (flat) 2BExisting roof (curved) 3Known retrofitting system 4Existing metal panel 5Ridge of metal panel 6Existing structural member (purlin, strut, etc.) 8Sub-purlin10New metal panel12Eave of roof (or direction of eave)13Eave line14Ridge (or direction of ridge)20Curvable sub-rafter22Bottom flange23Longitudinal Axis24Web25Vertical Axis26Slot27Direction27′Direction28Lower end of slot29Direction29′Direction30Hinge area32Exterior surface34Interior surface40Top wall (or top flange)42Portion of top wall44Sheet of a structural material45Long edges of sheet46Bend line50Top Band54Mechanical fastener60Roofing system for a curved roof62Cross-member64Notched sub-purlin66Hat channel68Top wall (or flange)70Leg (or web)71Notch72Base flangeDETAILED DESCRIPTION

[0087] Referring now to FIG. 1A, a known system 3 for retrofitting an existing flat metal roof 2A is generally illustrated. The existing metal roof 2A is slope in-plane and has existing metal panels 4 fixed to existing structural members 6 (i.e., purlins). The metal panels 4 extend between a lower end or eave of the roof (in the direction of reference numeral 12) and the upper end or ridge of the roof (in the direction of reference numeral 14). The known system 3 comprises new sub-purlins 8 that are positioned above the existing purlins 6 and then joined to the existing purlins. Thereafter, new metal panels 10 are affixed to the new sub-purlins 8.

[0088] As previously mentioned, this known system 3 only works if the existing metal panels 4 are linear in the same plane from the eave 12 to the ridge 14. This known system 3 will not work on an existing roof that is curved between the eave and the ridge.

[0089] Referring now to FIGS. 2A and 2B, a sub-rafter 20A according to embodiments of the present disclosure is generally illustrated. In FIGS. 2A and 2B, a sub-rafter 20A is shown having a shape that resembles a “Z” or a “Zee” shape as will be understood by those skilled in the art. As used herein, the term “curvable” or “conformable” refers to the ability of the sub-rafter 20A to conform to the shape of an underlying existing roof 2A and / or 2B, which may be a curved shape and / or a partially curved shape. As used herein, an “existing roof” or an “existing curved roof” generally refers to an existing roof that is curved and that needs or can be retrofitted by using a sub-rafter 20A to install a new roof. However, this is not necessarily limiting, as the sub-rafter 20A according to the present disclosure may also be used in connection with an existing curved structure of a building, including without limitation, an existing curved wall, fascia or another related curved structure.

[0090] The sub-rafter 20A generally comprises a bottom flange 22A, a top wall 40A (which may be referred to as a “flange”), a web 24A extending between the bottom flange and the top wall, and at least one slot 26. In one or more embodiments, the sub-rafter 20A may be described as having the shape of a structural zee as will be understood by those of skill in the art.

[0091] The bottom flange 22A is configured to be positioned on an exterior surface of an existing roof 2B that is curved or at least partially curved between an cave and a ridge. The slots 26 permit the bottom flange 22A to bend and / or partially bend to generally match, or at least substantially match, the curvature of the existing roof 2B. Connectors such as fasteners, bolts, screws, etc., may be driven through the bottom flange 22A to fasten or affix the sub-rafter 20A to the existing structural purlins, joists, girders, beams, roof deck, or other existing structural members 6 of the existing curved roof 2B as generally illustrated in FIG. 5A.

[0092] The web 24A generally extends away from the bottom flange 22A to the top wall 40A. The bottom flange 22A extends from a first side of the web 24A, and the top wall 40A extends from a second side of the web 14A that is opposite to the first side.

[0093] In some embodiments, the web 24A is oriented approximately perpendicular to the bottom flange 22A and / or the top wall 40A. However, this is not necessarily limiting as in other embodiments the web 24 is oriented at an angle of inclination relative to the flange 22A and / or the vertical plane. The web 24A is substantially planar in some embodiments. Alternatively, in other embodiments, the web 24A may have projections or protrusions to stiffen and / or strengthen the web 24A.

[0094] The top wall 40A is configured to support the weight of the material(s) of a new roof, including without limitation, new metal panels. Moreover, fasteners may be driven through the top wall 40A to secure the new roof material to the top wall and to the sub-rafter 20A.

[0095] Before the sub-rafter 20A is positioned on an exterior surface of the existing curved roof 2B, the sub-rafter may be described as being in a first or initial state. In the initial state, the top wall 40A generally assumes a planar shape. In some embodiments, the top wall 40A is substantially parallel to the bottom flange 22A when in the initial state, i.e., before the sub-rafter 20A is affixed to existing structural members beneath the exterior surface of the existing curved roof 2B.

[0096] The sub-rafter 20A may have any desired dimensions as needed to meet design requirements of a new roof, including design load requirements.

[0097] As generally illustrated in FIG. 2B, one or more slots 26 are formed in the sub-rafter 20A. The sub-rafter 20A may have any number of slots 26. In some embodiments the slots 26 are substantially uniformly spaced along a length of the sub-rafter. Alternatively, the slots 26 may have a variable spacing.

[0098] In one or more embodiments, a slot 26 is disposed approximately 12 inches from the ends of the sub-rafter 20A. In other embodiments, a slot 26 is disposed approximately 6″ from the ends of the sub-rafter 20A. However, this is not necessarily limiting as a slot 26 may be disposed closer or further away from the ends of the sub-rafter 20A.

[0099] In some embodiments, the slots 26 are formed approximately 4 inches apart. In other embodiments, the slots 26 are formed approximately 6 inches on center. In some embodiments, the slots 26 are formed approximately 8 inches on center. In other embodiments, the slots 26 are formed approximately 10 inches on center. In still other embodiments, the slots 26 are formed approximately 12 inches on center. In yet other embodiments, the slots 26 are formed approximately 14 inches on center. Optionally, the 26 slots may be formed between approximately 2 inches and 18 inches on center.

[0100] The slots 26 generally extend through the top wall 40A and at least partially into the web 24A toward the bottom flange 22A. The slots 26 generally divide the top wall 40A into a plurality of portions 42A, 42B . . . 42Z.

[0101] When the sub-rafter 20A is in the initial state, the slots 26 may have a width measured at a position other than the closed lower end, the width measured approximately parallel to a longitudinal axis of the sub-rafter. In some embodiments, the width is less than approximately 0.25 inch. In other embodiments, the width is less than approximately 0.1 inch. Alternatively, in other embodiments, the width is less than approximately 0.005 inch. In some embodiments, the width is approximately 0.03 inch. Optionally, the width is between approximately 0.02 inch and 0.3 inch.

[0102] Before the sub-rafter 20A is positioned on the exterior surface of an existing curved roof 2B (when the sub-rafter is in the initial state), the distance between adjacent portions (i.e., 42A and 42B) of the top wall 40A are substantially equal (and defined by the width of the slots 26). When the sub-rafter 20 is affixed to the structural members of an existing roof 2B that is curved (i.e., when in the second state), the distance between adjacent portions (i.e., 42A and 42B) of the top wall 40A will generally increase.

[0103] As shown in FIG. 2B, in embodiments a central sub-portion, e.g., 42C, will define a vertical axis 25 that is substantially transverse to the longitudinal axis 23. In one or more embodiments, the vertical axis 25 is at the approximate middle of a sub-portion, e.g., 42C, after the sub-rafter 20 is affixed to the existing roof 2B. As shown in FIG. 2B, in embodiments the axis 25 defines a delineation for adjacent sub-portions to at least partially shift in substantially opposite directions. As used herein, the term “shift” refers to a relative positional displacement, i.e., bending, moving or otherwise deflecting, of a sub-portion of the sheet 44 relative to an initial position before installation when the sub-rafter 20 is in a generally linear initial state. For example, as shown in FIG. 2B, sub-portions 42B and / or 42A will generally shift respectively in directions 27 and 29, when the sub-rafter 20 is affixed to the existing roof 2B with the middle portion 42C is at the approximate center of the curvature of the existing roof 2B. As a further example, as is also shown in FIG. 2B, sub-portions 42D and 42E will generally shift respectively in directions 27′ and 29′ (which are substantially opposite to directions 27 and 29), when the sub-rafter 20 is affixed to the roof 2B with the middle sub-portion 42C being at the approximate center of the curvature of the existing roof 2B.

[0104] The slots 26 generally do not extend into the bottom flange 22A. Accordingly, a lower end 28 of each slot 26 is a predetermined distance from the bottom flange 22A.

[0105] In some embodiments, the slots 26 extend about 25 percent of the extent of the web between the top wall 40A and the bottom flange 22A. In other embodiments, the slots 26 extend about 33 percent of the extent of the web between the top wall 40A and the bottom flange 22A. In still other embodiments, the slots 26 extend about 50 percent of the extent of the web 24A between the top wall 40A and the bottom flange 22A. In some embodiments, the slots 26 extend about 66 percent of the extent of the web 24A between the top wall 40A and the bottom flange 22A. In yet other embodiments, the slots 26 extend about 75 percent of the extent of the web 24A between the top wall 40A and the bottom flange 22A. In at least one embodiment, the slots 26 extend about 80 percent of the extent of the web 24A between the top wall 40A and the bottom flange 22A. Additionally, or alternatively, in some embodiments the slots 26 extend between about 15 percent and about 99 percent of the extent of the web 24A between the top wall 40A and the bottom flange 22A.

[0106] In at least some embodiments, the slots 26 optionally include a lower end 28 that is rounded. A rounded shape of the lower end 28 may beneficially prevent factures or cracks forming in the web 24A. For example, in some embodiments a rounded shape of the lower end 28 with an approximate diameter that is greater than the width of the slot 26 at least partially reduces the likelihood of fractures or cracks in the web 24 as it re-distributes strains around the circumference of the lower end.

[0107] In some embodiments, the lower end 28 is optionally generally circular or semi-circular. In at least one embodiment, the lower end 28 has a diameter that is greater than a width of the slot 26. Although the lower end 28 is illustrated and described as being generally round, circular or semi-circular, other shapes of the lower end 28 are contemplated.

[0108] An area between a lower end 28 of a slot 26 and the bottom flange 22A defines a hinge area 30. The hinge area 30 may bend, twist, expand, contract or otherwise deform as the bottom flange 22A bends to generally conform to the curvature profile of an existing curved roof 2B. Said differently, as the bottom flange 22A conforms to the profile of an existing curved roof, the relative spacing between adjacent sub-portions 42A, 42B, etc., generally increases to according to the curvature of the existing roof 2B. Accordingly, a substantially circular or semi-circular profile of the lower end 28 at least partially facilitates such adjustments, or positional shifts of the sub-portions, to the separation between adjacent sub-portions, 42A, 42B, etc., or otherwise to the width of individual slots 26. In embodiments, the width of the slots 26 before deformation is substantially uniform.

[0109] Referring now to FIG. 2C, in some embodiments, the slots 26 are formed while the sub-rafter 20A is being formed from a structural sheet that is substantially flat. In at least one embodiment, the slots 26 are formed in a structural sheet 44A which is subsequently formed into the sub-rafter 20A. The structural sheet includes a first long edge 45A and a second long edge 45B that is substantially parallel to the first long edge 45A. In embodiments, the long edges 45A and 45B are approximately parallel to a longitudinal axis 23 of the structural sheet 44.

[0110] In some embodiments, the slots 26 may optionally extend to the first long edge 45A of a structural sheet 44A, but they generally do not extend to the second long edge 45B. Accordingly, in at least some embodiments, closed ends 28 of the slots 26 are spaced from one or more of the first and second long edges 45A, 45B.

[0111] In embodiments, the slots 26 extend approximately perpendicular to the first long edge 45A and / or the second long edge 45B.

[0112] After the slots 26 are formed, the structural sheet 44 is generally cut to a suitable length. Thereafter, the structural sheet 44 is bent at one or more positions indicated by bend lines 46 to form the sub-rafter 20A.

[0113] The slots 26 and / or lower ends 28 may be formed in any suitable manner. In some embodiments, a laser, plasma torch, water jet or other means is used to form or cut the slots 26 without directly contacting the structural sheet. In some embodiments, a cutting tool (such as a saw, including a power saw, or a blade) contacts the sheet to form the slots 26. In further embodiments, a die cutting machine or a press is used to form the slots 26.

[0114] The structural sheet 44 may be formed of any suitable material of any thickness according to the specific design or need. For example, in some embodiments the structural sheet 44 is formed of a metal. Optionally, the metal comprises one or more of steel, stainless steel, aluminum, and / or related materials and / or alloys.

[0115] In other embodiments, the structural sheet 44 is a composite comprising a fiber. In some embodiments, the fiber comprises carbon.

[0116] In still other embodiments, the structural sheet comprises a plastic and / or a polymer.

[0117] In some embodiments, the structural sheet 44 has a thickness of between approximately 0.03 inches and approximately 0.12 inches. Optionally, the structural sheet 44 has a thickness of approximately 0.0635 inches (known as 16 gauge). Other thicknesses of the structural sheet 44 are contemplated. For example, in one or more embodiments, the structural sheet 44 and / or top band 50, which will be described below, comprises a 14-gauge thickness. In other embodiments, the structural sheet 44 and / or top band 50 comprises an 18-gauge thickness.

[0118] For example, in embodiments the structural sheet 44 and / or top band 50 comprises structural steel with a minimum tensile strength of approximately 50 kips per square inch (ksi). In at least one embodiment, the structural sheet 44 and / or top band 50 comprises structural steel with a higher tensile strength of approximately 80 ksi. In one or more embodiments, the structural sheet 44 and / or top band 50 comprises G90 galvanized steel.

[0119] Referring now to FIGS. 3A-3C, a sub-rafter 20B according to other embodiments of the present disclosure is generally illustrated. The sub-rafter 20B is similar to the sub-rafter 20A and includes many of the same or similar features.

[0120] Notably, the sub-rafter 20B comprises two bottom flanges 22B, two webs 24B, and a top wall 40B. The sub-rafter 20B may be described as having the shape of a structural hat as will be understood by those of skill in the art.

[0121] The bottom flanges 22B are configured to be positioned on an exterior surface of an existing roof 2B that is curved between an eave and a ridge. The slots 26 permit the bottom flanges 22B to bend in a longitudinal direction to generally match (or at least substantially or partially match) the curvature of the existing roof 2B. Mechanical fasteners 54 may be driven through the bottom flanges 22B, through the exterior surface of the existing roof 2B and into structural purlins 6, joists, or other existing structural members of the existing roof 2B to fasten or affix the sub-rafter 20B to the existing curved roof.

[0122] The webs 24B extend away from the bottom flanges 22B and extend to the top wall 40B. In some embodiments, the webs 24B are oriented at an oblique angle to each other, to the bottom flanges 22B and the top wall 40B. For example, an exterior angle between a bottom flange 22B and an exterior surface 32 of a web 24B may be described as an obtuse angle. Similarly, an interior angle between an interior surface 34 of a web 24B and the top wall 40B may be described as an obtuse angle.

[0123] In some embodiments, the interior angle between the interior surface 34 of a web 24B and the top wall 40B is between about 95° and about 125°. In other embodiments, the interior angle is about 106°.

[0124] Accordingly, the curvable sub-rafter 20B has a first width measured through the webs 24 proximate to the bottom flanges 22B. The top wall 40B has a second width that is less than the first width.

[0125] The webs 24B are substantially planar in some embodiments. Alternatively, in other embodiments, one or more of the webs may have projections or protrusions (not illustrated) to stiffen the webs and / or strengthen the webs 24B. In some embodiments, a stiffening protrusion may extend outwardly from an exterior surface 32 of a web 24B. In other embodiments, a stiffening protrusion may extend inwardly from an interior surface 34 of a web. A curvable sub-rafter may have one or more stiffening protrusions that extend outwardly from the exterior surface 32 and / or inwardly from the interior surface 34.

[0126] A stiffening protrusion may have any desired shape. In some embodiments a stiffening protrusion is generally linear. Additionally, or alternatively, a stiffening protrusion may have a shape that is not linear. For example, a stiffening protrusion may include a curved portion or a bend. In some embodiments, a stiffening protrusion includes one or more linear portions and one or more bends or curved portions. Suitable stiffening protrusions are known to those of skill in the art and are described in U.S. Pat. No. 11,466,457 which is incorporated by reference herein.

[0127] In at least one alternative embodiment, two sub-rafters 20A comprising a “Z” shape may be placed together side by side to collectively define an alternative “hat” shape. In such embodiments, the sub-rafters 20A are oriented toward one another with corresponding top walls 40B being disposed in an overlapping or otherwise nested arrangement, i.e., with a top wall 40B being disposed above or below the other top wall 40B. In embodiments, a top band 50, as will be described below, is disposed above the overlapping top walls 40B.

[0128] In one or more embodiments, the top wall 40B is configured to support a top band 50 (shown in FIG. 4A) and the new structure of the new roof. Moreover, mechanical fasteners 54 may be driven through the top band 50 and the top wall 40B (as shown in FIG. 4B) to secure new roofing materials (such as metal panels) to the top wall of the top band 50 and to the curvable sub-rafter 20B.

[0129] In an initial state before the curvable sub-rafter 20B is positioned on an exterior surface of a curved roof 2B, the top wall 40B and the bottom flanges 22B are generally planar. In some embodiments, the top wall 40B is substantially parallel to the bottom flanges 22B in the initial state before the curvable sub-rafter 20B is affixed to existing structural purlins, joists, girders, beams or other existing structural members 6 of the existing curved roof 2B.

[0130] The curvable sub-rafter 20B may have any desired dimensions and / or thicknesses needed to meet design load requirements of a new roof. In some embodiments, the curvable sub-rafter 20B has a height of between about 1 inch and about 8 inches. However, other heights are contemplated.

[0131] In some embodiments, a maximum width of the curvable sub-rafter 20B measured between free ends of the bottom flanges 22B is between about 4 inches and about 8 inches. In other embodiments, the maximum width is about 5.6 inches. Other widths are contemplated.

[0132] In some embodiments, the width of the top wall is between about 1.5 inches and about 4 inches. In other embodiments, the width of the top wall is about 2 inches. Other widths are contemplated.

[0133] As generally illustrated in FIG. 3B, one or more slots 26 are formed in the curvable sub-rafter 20B. The curvable sub-rafter 20B may have any number of slots 26. In some embodiments the slots are substantially uniformly spaced along a length of the curvable sub-rafter. Alternatively, the slots 26 may have a variable spacing.

[0134] In some embodiments, the slots 26 are formed approximately 4 inches apart. In other embodiments the slots 26 are formed approximately 6 inches on center. In some embodiments, the slots 26 are formed approximately 8 inches on center. In other embodiments, the slots are formed approximately 10 inches on center. In still other embodiments, the slots 26 are formed approximately 12 inches on center. In yet other embodiments, the slots 26 are formed approximately 14 inches on center. Optionally, the slots 26 may be formed between approximately 2 inches and 18 inches on center.

[0135] The slots 26 generally extend through the top wall 40B and into the webs 24B toward the bottom flanges 22B. The slots divide the top wall 40B into a plurality of portions 42A, 42B 42Z.

[0136] Before the curvable sub-rafter 20B is affixed to existing structural members 6 of a curved roof 2B, the distance between adjacent portions (i.e., 42A and 42B) of the top wall 40B are substantially equal (and defined by the width of the slots 26). When the curvable sub-rafter 20 is in the second state and bent to be affixed to an existing roof 2B that is curved or at least partially curved, the distance between adjacent portions (i.e., 42A and 42B) of the top wall 40B will generally increase, for example as shown in the illustrative embodiment of FIG. 3C.

[0137] When the sub-rafter 20A is in the initial state, the slots 26 may have a width measured at a position other than the closed lower end, the width measured approximately parallel to a longitudinal axis of the sub-rafter. In some embodiments, the width is less than approximately 0.25 inch. In other embodiments, the width is less than approximately 0.1 inch. Alternatively, in other embodiments, the width is less than approximately 0.005 inch. In some embodiments, the width is approximately 0.03 inch. Optionally, the width is between approximately 0.02 inch and 0.3 inch.

[0138] Generally, the slots 26 do not extend into the bottom flanges 22B. Accordingly, a lower end 28 of each slot is a predetermined distance from the bottom flanges 22B.

[0139] In some embodiments, the slots 26 extend about 25 percent of the extent of the webs 24B between the top wall 40B and the bottom flanges 22B. In other embodiments, the slots 26 extend about 33 percent of the extent of the webs 24B between the top wall 40 and the bottom flanges 22B. In still other embodiments, the slots 26 extend about 50 percent of the extent of the webs 24B between the top wall 40 and the bottom flanges 22B. In some embodiments, the slots 26 extend about 66 percent of the extent of the webs 24B between the top wall 40 and the bottom flanges 22B. In yet other embodiments, the slots 26 extend about 75 percent of the extent of the webs 24B between the top wall 40 and the bottom flanges 22B. In at least one embodiment, the slots 26 extend about 80 percent of the extent of the webs 24B between the top wall 40 and the bottom flanges 22B. Additionally, or alternatively, in some embodiments the slots 26 extend between about 15 percent and about 99 percent of the extent of the webs 24B between the top wall 40 and the bottom flanges 22B.

[0140] In at least some embodiments, the slots 26 optionally include a lower end 28 that is rounded. The rounded shape of the lower end 28 may beneficially prevent factures or cracks forming in the webs 24B.

[0141] In some embodiments, the lower end 28 is optionally generally circular. In at least one embodiment, the lower end 26 has a diameter that is greater than a width of the slot 26 (at least when the sub-rafter 20B is in its initial state). Although the lower end 28 is illustrated and described as being generally round or circular, other shapes of the lower end 28 are contemplated.

[0142] An area between a lower end 28 of a slot 26 and the bottom flanges 22B defines a hinge area 30. The hinge area 30 may bend, twist, expand, contract or otherwise deform as the bottom flanges 22B bends to conform to the curvature of an existing roof 2B.

[0143] Referring now to FIG. 3D, in some embodiments, the slots 26 are formed while the curvable sub-rafter 20B is being formed from a structural sheet 44 that is substantially flat (or “planar”). More specifically, in at least one embodiment, the slots 26 are formed in a structural sheet 44 which is subsequently formed into the curvable sub-rafter 20B. The structural sheet 44 includes a first long edge 45A and a second long edge 45B that is substantially parallel to the first long edge. The long edges 45 are approximately parallel to a longitudinal axis 23 of the structural sheet 44.

[0144] In embodiments, the slots 26 do not extend to either the first long edge 45A or the second long edge 45B.

[0145] In embodiments, the slots 26 extend approximately perpendicular to the first long edge 45A and / or the second long edge 45B.

[0146] In embodiments, the width of the slots 26 is substantially uniform when the sub-rafter 20 is in the initial state (before the sub-rafter 20 is installed on a curved surface). In other embodiments, the width of the slots 26 after deformation is largest proximate to the lower end 28 and is smaller as the width approach the top wall 40B. Thus, in such embodiments a deformation of the bottom flange 22A to conform to the curvature of the existing roof 2B generally results in a reduced separation or with of the slots 26 compared to slots 26 with a substantially uniform width before installation.

[0147] In embodiments, after the slots 26 are formed, the structural sheet 44 is cut to a suitable length. Thereafter, the structural sheet is bent at one or more positions indicated by bend lines 46 to form the curvable sub-rafter 20B.

[0148] The slots 26 (including their closed ends 28) may be formed in any suitable manner. In some embodiments, a laser, plasma torch, water jet or other means is used to form or cut the slots 26 without directly contacting the structural sheet. In some embodiments, a cutting tool (such as a saw, including a power saw, or a blade) contacts the structural sheet to form the slots 26. In further embodiments, a die cutting machine or a press is used to form the slots 26.

[0149] The structural sheet 44B may be formed of any suitable material of any thickness according to the specific design or need. For example, in some embodiments the structural sheet 44 is formed of a metal. Optionally, the metal comprises one or more of steel, stainless steel, and aluminum, and / or related materials and / or alloys.

[0150] In other embodiments, the structural sheet is a composite comprising a fiber. In some embodiments, the fiber comprises carbon.

[0151] In still other embodiments, the structural sheet comprises a plastic and / or a polymer.

[0152] In some embodiments, the structural sheet 44B has a thickness of between approximately 0.03 inches and approximately 0.12 inches. Optionally, the structural sheet 44 has a thickness of approximately 0.0635 inches (known as 16 gauge). Other thicknesses of the structural sheet 44 are contemplated. For example, in one or more embodiments, the structural sheet 44B and / or top band 50, which will be described below, comprises a 14-gauge thickness. In other embodiments, the structural sheet 44B and / or top band 50 comprises an 18-gauge thickness.

[0153] For example, in embodiments the structural sheet 44B and / or top band 50 comprises structural steel with a minimum tensile strength of approximately 50 ksi. In at least one embodiment, the structural sheet 44B and / or top band 50 comprises structural steel with a higher tensile strength approximately 80 ksi. In one or more embodiments, the structural sheet 44 and / or top band 50 comprises G90 galvanized steel.

[0154] The structural sheet 44B used to form the curvable sub-rafter 20B may be the same as (or different from) the structural sheet 44A used to form the curvable sub-rafter 20A.

[0155] Referring now to FIGS. 4A-4C, a curvable sub-rafter 20B is generally illustrated with a top band 50 attached to the top wall 40B. The curvable sub-rafter 20B is illustrated as being linear in FIGS. 4A-4C for illustration purposes only. In embodiments, the top band 50 is attached to the top wall 40B after the curvable sub-rafter 20B is in the second state and curved (or bent) to fit the curvature of an existing roof 2B, as generally illustrated in FIG. 4D. In one or more embodiments, after the curvable sub-rafter 20B is bent or curved to a desired amount (such as to generally or substantially conform the curvature of an existing curved roof 2B), the top band 50 is attached to the top wall 40B in any suitable manner.

[0156] In some embodiments, as generally illustrated in FIGS. 4A-4B, a mechanical fastener 54A is driven through the top band 50 and the top wall 40 to attach the top band to the sub-rafter.

[0157] In at least one embodiment, at least one mechanical fastener 54A is driven through the top band 50 and the top wall 40 between each pair of adjacent slots 26.

[0158] Any suitable mechanical fastener known to those of skill in the art may be used. In some embodiments, the mechanical fastener 54A is a threaded fastener or a rivet. Optionally, the mechanical fastener 54A may be a metal screw of any appropriate size and threading.

[0159] In some embodiments the mechanical fasteners 54A are positioned between about 2 inches and about 8 inches apart. In at least one embodiment, the mechanical fasteners 54A are positioned about 4 inches apart.

[0160] Alternatively, in other embodiments, the top band 50 may be affixed or attached to the top wall 40B by welding, soldering or brazing, crimping, clinching, or any other suitable method known to those of skill in the art.

[0161] In embodiments, the top band 50 spans a vertical slot(s) to form a continuous tension band. In some embodiments, the top band 50 generally has a width approximately equal to the width of the top wall 40. Optionally, the width of the top band 50 is less than the width of the top wall.

[0162] In some embodiments the width of the top band 50 is between about 1.5 inches and about 4 inches. In other embodiments, the width of the top band is about 2 inches. Other widths for the top band 50 are contemplated.

[0163] In some embodiments, the top band 50 is formed from a sheet of a structural material. The top band 50 may be formed of any suitable metal of any thickness. For example, in some embodiments the top band 50 is formed of a metal. Optionally, the metal of the top band comprises one or more of steel, stainless steel, aluminum, alloys and / or combinations thereof.

[0164] In other embodiments, the top band 50 is formed of a composite comprising a fiber. In some embodiments, the fiber comprises carbon.

[0165] In still other embodiments, the top band 50 comprises a plastic and / or a polymer.

[0166] In some embodiments, the top band 50 is formed of a structural material that is the same as the structural material used to form the curvable sub-rafters 20A, 20B (i.e., the structural sheets 44A, 44B). Alternatively, in other embodiments, top band 50 is formed of a structural material that is different than the structural material used to form the curvable sub-rafters 20A, 20B.

[0167] In some embodiments, the top band 50 has a thickness of between approximately 0.03 inches and approximately 0.12 inches. Optionally, the top band 50 has a thickness of approximately 0.0635 inches (known as 16 gauge). Other thicknesses of the top band 50 are contemplated.

[0168] In some embodiments, the top band 50 has a thickness that is approximately equal to a thickness of the curvable sub-rafters 20A, 20B.

[0169] Additionally, or alternatively, in other embodiments, the top band 50 has a thickness that is greater than a thickness of the curvable sub-rafters 20A, 20B.

[0170] In still other embodiments, the top band 50 has a thickness that is not less than a thickness of the curvable sub-rafters 20A, 20B.

[0171] In some embodiments, the top band 50 has a first length that is about equal to a second length of the curvable sub-rafters 20A, 20B when the sub-rafters are in the second state.

[0172] In other embodiments, the first length of the top band 50 is less than the second length of the curvable sub-rafters 20A, 20B when the sub-rafters are in the second state.

[0173] In some embodiments, the first length of the top band 50 is about 150 percent of a length between two slots of the curvable sub-rafters 20A, 20B when the sub-rafters are in the second state.

[0174] Referring now to FIG. 4E, the top band 50 is shown temporarily attached to a curvable sub-rafter 20B after the curvable sub-rafter has been bent at least partially into the second state.

[0175] Referring now to FIGS. 5A and 5B, portions of a roofing system 60 of embodiments of the present disclosure is generally illustrated. The roofing system 60 is installed over (or attached to) an existing curved roof 2B comprising existing metal panels 4 that are curved between the eave 12 and the ridge 14.

[0176] The curved roof 2B generally comprises existing structural members 6 (such as struts, girders, beams and purlins) that are oriented approximately parallel to an eave line 13 defined by the eave 12. The structural members 6 have a predetermined spacing between the eave 12 and the ridge 14. Metal panels 4 are affixed to the structural members 6.

[0177] As generally illustrated in FIG. 5A, the roofing system 60 of the present disclosure comprises curvable sub-rafters 20B that are attached to the existing roof 2B. The curvable sub-rafters 20B generally extend between the eave 12 and the ridge 14 of the existing roof 2B. More specifically, the curvable sub-rafters 20B are oriented approximately perpendicular to the existing structural members 6 of the existing roof 2B. As shown in FIG. 5B, the curvable sub-rafters 20B are affixed to the existing roof 2B with mechanical fasteners 54B that extend through the metal panels 4 and into the existing structural members 6 of the existing curved roof 2B.

[0178] After the curvable sub-rafters 20B are attached to the existing roof 2B, cross-members 62 are positioned over the curvable sub-rafters 20B and attached to the curvable sub-rafters. In some embodiments, the cross-members 62 are also attached directly to the structural members 6 of the existing curved roof 2B.

[0179] The cross-members 62 are aligned approximately perpendicular to the curvable sub-rafters 20B. Accordingly, in at least some embodiments, the cross-members 62 are oriented approximately parallel to the existing purlins 6.

[0180] In embodiments, cross-members 62 are positioned over (i.e., vertically aligned with) each existing structural member 6. For example, FIG. 5A generally illustrates cross-members 62A of the roofing system 60 aligned vertically with the existing structural members 6 of the existing curved roof 2B.

[0181] Additionally, or alternatively, in one or more embodiments at least some cross-members 62B of the roofing system 60 are optionally positioned between the existing structural members 6 of the existing curved roof 2B. For example, as shown in FIG. 5A, new cross-members 62B are positioned between new cross-members 62B of the roofing system 60 and between the existing structural members 6 of the existing curved roof 2B. Accordingly, in some embodiments the roofing system 60 may include more cross-members 62 than the structural members 6 of the existing curved roof 2B. In this manner, the roofing system 60 of the present disclosure may provide more up-lift resistance for new metal panels secured to the cross-members, and / or greater strength, compared to the existing curved roof 2B with fewer structural members 6.

[0182] In some embodiments, the cross-members 62 are sub-purlins 64. Referring now to FIG. 5C, a sub-purlin 64 according to embodiments of the present disclosure is generally illustrated. The sub-purlin 64 generally comprises a top wall 68A (or top flange), a leg 70A (or web) that extends downwardly from the top wall, and a base flange 72A extending outwardly away from the leg. The leg 70A is oriented approximately orthogonal to the top wall 68A and the base flange 72A. In some embodiments, the top wall and the base flange are approximately parallel. In some embodiments, the sub-purlin 64 is formed of a metallic material, such as steel.

[0183] The sub-purlin 64 includes one or more notches 71 to fit over ridges and / or seams of the existing metal panels 4 of the curved roof 2B and the curvable sub-rafters 20B of the roofing system 60. The notches 71 extend through the base flange 72A and into the leg 70A. However, the notches 71 do not extend into the top wall 68A. The notches 71 may have any desired shape to fit over the seams and ridges of the metal panels 4 and the curvable sub-rafters 20B.

[0184] Alternatively, the cross-members 62 are channels 66. In one or more embodiments, the channels 66 comprise a “hat” shape. In embodiments, the channels 66 are attached to the curvable sub-rafters 20B.

[0185] Referring now to FIG. 5D, a channel 66 according to embodiments of the present disclosure is generally illustrated. The channel 66 generally comprises a top wall 68B (or flange), legs 70B (or webs) that extend downwardly from the top wall, and a base flange 72B extending outwardly from each leg. The legs 70B are generally oriented at an oblique angle to the top wall 68B and the base flanges 72B. In some embodiments, the top wall 68B and the base flanges 72B are approximately parallel. In some embodiments, the channel 66 is formed of a metallic material, such as steel.

[0186] Referring again to FIG. 5A, after the curvable sub-rafters 20 and cross-members 62 are secured to the existing structural members 6 of the existing roof 2B, a new roof structure may be affixed to the cross-members 62 to complete the new roofing system 60. For clarity, the new roof structure is not illustrated in FIGS. 5A and 5B. However, new metal panels 10 may be attached to the cross-members 62 as generally known to those of skill in the art, such as generally illustrated in FIG. 1, for example. Alternatively, a new roof structure of any material (such as a composite shingle, plastic, and others) may be attached to the cross-members 62.

[0187] Optionally, new metal panels that are the same as or similar to the existing metal panels 4 may be attached to the cross-members. Alternatively, the new metal panels may be of a different type than the existing metal panels 4.

[0188] As generally illustrated in FIG. 5B, the curvable sub-rafter 20B is affixed to the existing metal roof structural members 6 by a mechanical fastener 54B. In some embodiments, the mechanical fastener 54B is the same as or similar to the mechanical fastener 54A.

[0189] Optionally, the mechanical fastener 54B is a threaded fastener. In some embodiments, the mechanical fastener 54B is driven through the bottom flange 22B, through the existing metal panel 4 and into the existing structural member 6 (such as a purlin). In embodiments, two mechanical fasteners 54B are driven through each bottom flange 22B and into each existing structural member 6 of the existing metal roof.

[0190] FIG. 5B also illustrates a sub-purlin 64 of roofing system 60. Although not illustrated, the sub-purlin 64 may extend over the curvable sub-rafter 20B.

[0191] Alternatively, FIG. 5B also illustrates a channel 66 of embodiments of the present disclosure that may be used with (or instead of) the sub-purlin 64. The channel 66 is oriented approximately perpendicular to the curvable sub-rafter 20B. Once the channel 66 is positioned appropriately, it is attached to the curvable sub-rafter 20B by any suitable manner.

[0192] In some embodiments, a mechanical fastener 54C is driven through base flanges 72B of the channel 66 and through the top band 50 and the top wall 40B of the curvable sub-rafter 20B. New metal panels may subsequently be attached to channels 66 attached to the curvable sub-rafters in any suitable manner.

[0193] Referring now to FIG. 6, portions of a roofing system 60 of embodiments of the present disclosure are generally illustrated. The roofing system generally comprises a curvable sub-rafter 20B positioned on existing metal panels 4 and attached to the existing structural members 6 (not shown in FIG. 6) of an existing roof 2B of a building. Cross-members 62 are attached to the curvable sub-rafter 20B. In some embodiments, the cross-members 62 are channels 66.

[0194] Although the curvable sub-rafters 20A, 20B are generally described herein for use with an exterior curved roof, the curvable sub-rafters 20A, 20B may also be used as part of a curved wall or a curved ceiling. Accordingly, the curvable sub-rafters 20A, 20B of the present disclosure may be affixed to joists of a ceiling structure or studs of a vertical wall as part of an interior surface (a wall or a ceiling) of a building.

[0195] With reference to FIG. 7, embodiments according to the present invention are directed to a method 100 of forming a sub-rafter 20. As indicated at 110, in one or more embodiments, the method 100 comprises providing a sheet 44 as described herein. For example, in embodiments the sheet 44 extends along a longitudinal axis 23 and comprises a structural material. In embodiments and as is indicated at 120, the method 100 further comprises forming a plurality of slots 26 as described herein in the structural sheet 44. In embodiments, the method 100 comprises forming two or more slots 26 being spaced apart along the longitudinal axis 23. In at least one embodiment, the method 100 comprises forming two or more slots 26 on the sheet 44, the slots 26 being oriented approximately perpendicular to the longitudinal axis 23.

[0196] As shown at 130, in one or more embodiments the method 100 further comprises cutting the structural sheet material to a predetermined length according to the intended application, dimensional constraints such as the length and / or curvature of the existing roof 2B, etc. As shown at 140, the method 100 further comprises folding the sheet 44 to define a bottom flange 22, a web 24 and a top wall 40. In at least one embodiment, the method 100 comprises folding the sheet 44 in at least three locations or fold lines that are approximately parallel to the longitudinal axis 23 of the sub-rafter 20. In one or more embodiments, the method 100 optionally comprises folding the sheet 44 in four locations or fold lines to define two bottom flanges 22, two webs 24 and a top wall 40.

[0197] In one or more embodiments according to the present disclosure, the resulting sub-rafter 20 comprises a bottom flange 22, a web 24 and a top wall 40. In embodiments, the web 24 extends from the bottom flange 22 to the top wall 40. In one or more embodiments, the resulting sub-rafter 20 comprises slots 26 that extend through the top wall 40 and at least partially through the web 24 toward the bottom flange 22. In embodiments a closed end 28 of each slot 26 is spaced apart from the bottom flange 22. As such, the resulting sub-rafter 20 comprises a web 24 with an area below the slot 26 that can bend, i.e., expand or contract, or otherwise act as a hinge such that the sub-rafter can conform to the geometry of the existing roof 2B.

[0198] While various embodiments of the system and method have been described in detail, it is apparent that modifications and alterations of those embodiments will occur to those skilled in the art. It is to be expressly understood that such modifications and alterations are within the scope and spirit of the present disclosure. Further, it is to be understood that the phraseology and terminology used herein is for the purposes of description and should not be regarded as limiting. The use of “including,”“comprising,” or “having” and variations thereof herein are meant to encompass the items listed thereafter and equivalents thereof, as well as additional items. Further, it is to be understood that the claims is not necessarily limited to the specific features or steps described herein. Rather, the specific features and steps are disclosed as embodiments of implementing the claimed systems and methods.

[0199] One aspect of the disclosure comprises any one or more of the aspects / embodiments as substantially disclosed herein.

[0200] Another aspect of the disclosure is any one or more of the aspects / embodiments as substantially disclosed herein optionally in combination with any one or more other aspects / embodiments as substantially disclosed herein.

[0201] It is another aspect of the present disclosure to provide one or more means adapted to perform any one or more of the above aspects / embodiments as substantially disclosed herein.

[0202] To provide additional background, context, and to further satisfy the written description requirements of 35 U.S.C. § 112, the following references are incorporated by reference herein in their entireties: U.S. Pat. Nos. 8,024,906; 10,815,657; 11,466,457; and U.S. Patent Application Publication No. 20180073242.

Claims

1. A sub-rafter configured for installation on a roof of a building, the roof being at least partially curved between an eave and a ridge, the sub-rafter comprising:a bottom flange;a top wall spaced from the bottom flange;a web disposed between the bottom flange and the top wall;a slot extending through the top wall and at least partially through the web toward the bottom flange, wherein a closed end of the slot is spaced from the bottom flange; andthe bottom flange being conformable to a shape of the roof between the eave and the ridge.

2. The sub-rafter of claim 1, wherein at least one of the bottom flange and the top wall is planar when the sub-rafter is in an initial state and is generally linear, and wherein at least one of the bottom flange and the top wall is not planar when the sub-rafter is in a second state that is not linear.

3. The sub-rafter of claim 1, wherein the top wall is approximately parallel to the bottom flange when the sub-rafter is in the initial state, and wherein the top wall is not parallel to the bottom flange when the sub-rafter is in the second state.

4. The sub-rafter of claim 1, wherein the web is oriented approximately perpendicular to one or more of the top wall and the bottom flange.

5. The sub-rafter of claim 1, wherein:the web is a first web that extends from a first long edge of the top wall; andthe bottom flange is a first bottom flange that extends from the first web; andwherein the sub-rafter further comprises:a second web extending from a second long edge of the top wall, wherein the slot at least partially extends into each of the first and second webs;a second bottom flange that extends from the second web, andthe second bottom flange being conformable to the curvature of the roof between the eave and the ridge.

6. The sub-rafter of claim 1, wherein the closed end of the slot is rounded and has a diameter that is greater than a width of the slot when the sub-rafter is in an initial state.

7. The sub-rafter of claim 1, wherein the sub-rafter comprises a metallic material with a substantially uniform thickness or a composite material comprising carbon fiber with a substantially uniform thickness.

8. The sub-rafter of claim 1, wherein the slot is oriented approximately perpendicular to a reference plane defined by the top wall when the sub-rafter is in an initial state.

9. The sub-rafter of claim 1, further comprising a top band affixable to the top wall after the sub-rafter is bent and the sub-rafter is in the second state.

10. The sub-rafter of claim 9, wherein the top band extends from a first portion of the top wall on a first side of the slot, across the slot, and to a second portion of the top wall on a second side of the slot.

11. The sub-rafter of claim 10, wherein the top band is affixed to the top wall with:a first fastener that extends through the top band and the first portion of the top wall; anda second fastener that extends through the top band and the second portion of the top wall.

12. The sub-rafter of claim 9, wherein the top band is formed of a metallic material or a composite material, wherein the top band has a first thickness that is substantially uniform and equal to or greater than a second thickness of the top wall.

13. The sub-rafter of claim 1, further comprising a first length measured along the top wall when the sub-rafter is in the initial state, and wherein the top band has a second length that extends across at least a majority of the first length.

14. A roofing system affixed to an existing roof that is curved between an eave and a ridge or peak, comprising:a curvable sub-rafter disposed over an exterior surface of the existing roof and being attached to an existing structural member, the sub-rafter extending between the eave and the ridge and oriented approximately perpendicular to the structural member, wherein the sub-rafter comprises:a bottom flange;a top wall spaced from the bottom flange;a web extending between the bottom flange and the top wall; anda slot extending through the top wall and at least partially into the web;a top band fastened to the top wall, wherein:the bottom flange is conformable to a curvature of the roof between the eave and the ridge,a first mechanical fastener extends through the top band and through a first portion of the top wall on a first side of the slot; anda second mechanical fastener extends through the top band and through a second portion of the top wall on second side of the slot such that the top band bridges the slot;a cross-member positioned on the top band and attached to the curvable sub-rafter; anda new roof structure attached to the cross-member.

15. The roofing system of claim 14, wherein the cross-member is aligned vertically with the structural member of the roof and is oriented approximately perpendicular to the sub-rafter.

16. The roofing system of claim 15, further comprising a second cross-member positioned on the top band and attached to the sub-rafter, the second cross-member oriented approximately parallel to the first cross-member, wherein the second cross-member is positioned between two structural members.

17. The roofing system of claim 14, wherein a closed lower-end of the slot is generally circular.

18. The roofing system of claim 17, wherein:a lower portion of the slot proximate to the closed lower-end has a first width measured between two linear edges of the slot, andan upper portion of the slot proximate to the top wall has a second width measured between the two linear edges of the slot, the second width being greater than the first width.

19. A method of forming a sub-rafter, comprising:providing a structural sheet material that extends along a longitudinal axis;forming at least two slots in the structural sheet material, the slots spaced along the longitudinal axis and oriented approximately perpendicular to the longitudinal axis;cutting the structural sheet material to a predetermined length; andfolding the structural sheet material along three lines approximately parallel to the longitudinal axis to form the sub-rafter, wherein the curvable sub-rafter comprises:a bottom flange;a top wall;a web extending from the bottom flange to the top wall; andthe slots extending through the top wall and at least partially through the web toward the bottom flange, wherein a closed end of each slot is spaced from the bottom flange.

20. The method of claim 19, wherein the structural sheet material comprises at least one of a metal, a composite material, and a plastic.

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