Roofing member

Claim 2

An improved roofing member for use with other similar roofing members in an overlapping relationship which comprises a main body portion, an upstanding web along one edge, a downformed web along the opposite edge, the said webs of two roofing members when engaged one on the other defining between them a transverse cavity which forms a combined air expansion chamber and water trap having a water discharge point at a lip outwardly of said upstanding web and lower than a water overflow point, said chamber being defined by forming a downwardly opening transverse channel terminating in a lip along an intermediate portion of the down turned web and shaping the top portion of the upstanding web so that it engages the said lip linearly but continues upward to form a wall spaced from that part of the channel above the lip to terminate in the upper part of the channel, said upstanding web engaging the said downformed portion linearly behind the said cavity to press the said upstanding web against the said lip, whereby to form a water meniscus at said lip to restrict air flow into said cavity and water flow over the top portion of the upstanding web under adverse wet and windy conditions.

Claim 3

An improved roofing member according to claim 1 wherein the top of the upstanding web engages linearly a wedge portion on the downformed portion which is angled to engage the top of the upstanding wedge and urge it toward the said lip of the roofing member as it is moved into engagement with the associated member.

Claim 4

An improved roofing member according to claim 1 wherein the said chamber is defined by forming a downwardly opening transverse channel along an intermediate portion of the down turned web and turning over the top portion of the upstanding web and then turning it down so that it engages the said channel and has a double thickness to form with the channel a transverse stiffener along the said roofing member.

Claim 5

An improved roofing member according to claim 1 wherein the upstanding web of the one roofing member is engaged at least two linear transverse locations by the roofing member to which it is being attached, the first location being the aforesaid lip, and the other location being at a ridge which engages the rear of the said upturned portion to form a fulcrum during positioning of the upformed ridge in the downwardly opening channel said interengaging members being bent to form loading means for maintaining contact at the said lip.

Claim 6

An improved roofing member according to claim 4 characterised in that the upstanding portion is double walled and is formed to have a rising portion the upper part of which is adapted to engage the said lip, the top of the rising portion extending rearwardly and then upwardly and then down to form a wall portion spaced rearwardly of the said rising portion, lying substantially parallel to the upstanding portion, the said latter downwardly extending portion defining a springy structure which, when engaged by said ridge on the down turned portion, urges the upstanding portion of the said web into contact with the said lip.

Claim 7

An improved roofing member according to claim 1 characterised by a slit intermediate the ends of the down turned web, and flattened portions on the upstanding web at each end thereof of a length substantially that of the said slit whereby when the upstanding web of one such roofing member is engaged in the downwardly opening channel of an associated roofing member, the said flattened portion is engaged in said slit and locates said roofing member.

Claim 8

An improved roofing member according to claim 1 characterised by slits at each end of the down turned web, and corresponding flattened portions on the upstanding web at each end thereof whereby when the upstanding web of one such roofing member is engaged in the downwardly opening channel of an associated roofing member, the said flattened portions overlap to form with the down turned portion, the said cavity.

Claim 9

An improved roofing member according to claim 7 wherein the down turned web of said roofing member has a central slit to engage the said flattened portions of two overlapping members whereby to serve as aligning means for the ends of said roofing members when the said overlapping ends engage the said central slit and also to seal said slits against water flow therethrough.

Claim 10

An improved roofing member according to claim 1 wherein the main body portion has a series of stiffening deformations extending substantially between the upstanding web of said member and the down turned web of said member and wherein the stiffening deformations are so formed that end stiffening deformations on each member are complementary when two said members are overlapped in lateral alignment.

Claim 11

An improved roofing member according to claim 9 in which the end deformations at the extreme edges of the said members are shaped to engage the associated member to prevent the members from contacting at the overlap excepting at the said edge whereby to separate the members to form a cavity and whereby a meniscus is formed at the outer end of said cavity to restrict air flow into said cavity and to restrict water flow over a raised part of the stiffening deformation within the overlap under adverse wet and windy conditions.

Claim 12

An improved roofing member according to claim 6 wherein the deformations have a flattened M shape.

Claim 13

An improved roofing member according to claim 9 wherein the stiffening deformations are upstanding from the main body portion of each roofing member and extend to the upstanding web whereby to discourage lateral water flow.

Claim 14

An improved roofing member according to claim 9 wherein the stiffening deformations are upstanding from the main body portion of each roofing member, and the surface between said stiffening deformations slopes downward from the said upstanding web at a greater angle than the remaining surface whereby to shed water more effectively near the join formed between said upstanding web and said downformed web.

Claim 15

An improved roofing member for use with other similar roofing members in an overlapping relationship which comprises a. a main body portion, b. an upstanding web along one transverse edge formed by extending an edge portion of the sheet upwards and then rearward and upward to form a rising wall and then downwards to form a rear part which can be sprung towards the first upwardly projecting part, c. a downformed web along the opposite edge of the said main body portion formed by extending down the edge portion of the main body portion and doubling back to form a downwardly projecting channel having a wedge portion at the upper rearward part of the channel and extending down but including in the downward extension a transverse fulcrum ridge, and then extending substantially in the plane of the main body to form fixing means for the roofing member, d. a series of stiffening deformations in the surface substantially between the upstanding web and the down turned web of the said member; the said stiffening deformations being so formed that when the edges of two sheets are overlapped the stiffening formations at the overlap are substantially complementary, the dimensioning of the said webs being such that when the said upstanding web along one edge is engaged in the downformed web along the opposite edge, the webs defined between them a transverse cavity which forms a water trap and air expansion chamber, the said chamber being closed at an outer part by linear engagement between a part of the upstanding web against a forward lip of the transverse channel on the downformed web while the rearward portion of the upstanding web engages at least the fulcrum portion of the downwardly opening channel; whereby to form a water meniscus at the said lip to restrict air flow into said cavity and water flow over the top portion of the upstanding web under adverse wet and windy conditions.

Claim 16

An improved roofing member for use with other similar roofing members in an overlapping relationship which comprises a. a main body portion, b. an upstanding web along one transverse edge formed by extending an edge portion of the sheet upwards and then rearward and upward to form a rising wall and then downwards to form a rear part which can be sprung towards the first upwardly projecting part, c. a downformed web along the opposite edge of the said main body portion formed by extending down the edge portion of the main body portion and doubling back to form a downwardly projecting channel having a wedge portion at the upper rearward part of the channel and extending down but including in the downward extension a transverse fulcrum ridge, and then extending substantially in the plane of the main body to form fixing means for the roofing member, d. a series of stiffening deformations in the surface substantially between the upstanding web and the down turned web of the said member; the said stiffening deformations being so formed that when the edges of two sheets are overlapped the stiffening formations at the overlap are substantially complementary, the dimensioning of the said webs being such that when the said upstanding web along one edge is engaged in the downformed web along the opposite edge, the webs defined between them a transverse cavity which forms a water trap and air expansion chamber, the said chamber being closed at an outer part by linear engagement between a part of the upstanding web against a forward lip of the transverse channel on the downformed web while the rearward portion of the upstanding web engages at least the fulcrum portion of the downwardly opening channel; whereby to form a water meniscus at the said lip to restrict air flow into said cavity and water flow over the top portion of the upstanding web under adverse wet and windy conditions.

Claim 17

An improved roofing member according to claim 14 characterised by a slit at each end of the down turned web and a central slit therein, and corresponding flattened portions on the upstanding web at each end thereof, whereby when the upstanding web of one such roofing member is engaged in the downwardly opening channel of an associated roofing member, the flattened portions engage in said central slit, whereby to form aligning means for the ends of the said roofing members when the said overlapping ends engage the said central slit and to seal said slit against water flow therethrough.