Isolating roofing element

Abstract

The invention relates to a roofing element ( 1 ), comprising an upper ( 2 ) and a lower ( 3 ) layer of sheet material, which are spaced apart from each other, and in between and bonded thereto, an intermediate layer ( 4 ) of an insulating material, and is characterized in that the intermediate layer ( 4 ) partly fills the space between the upper and lower layers, so as to form along a first side of the element, a first projection portion ( 5 ) on the lower layer for attaching the roofing element to the roof substructure, and a second projection portion ( 6 ) on the upper layer, which first and second projections ( 5 ) and ( 6 ) enclose an open space ( 7 ), said roofing element further comprising a protruding portion ( 8 ) at a second side of the element, which protruding portion ( 8 ) is engageable with open space ( 7 ) of a second shape-similar element to join the two roofing elements.

1 . Roofing element ( 1 ), comprising an upper ( 2 ) and a lower ( 3 ) layer of sheet material, which are spaced apart from each other, and in between and bonded thereto, an intermediate layer ( 4 ) of an insulating material, characterized in that the intermediate layer ( 4 ) partly fills the space between the upper and lower layers, so as to form along a first side of the element, a first projection portion ( 5 ) on the lower layer for attaching the roofing element to the roof substructure, and a second projection portion ( 6 ) on the upper layer, which first and second projections ( 5 ) and ( 6 ) enclose an open space ( 7 ), said roofing element further comprising a protruding portion ( 8 ) at a second side of the element, which protruding portion ( 8 ) is engageable with open space ( 7 ) of a second shape-similar element to join the two roofing elements.  
   
   
       2 . Roofing element according to  claim 1 , characterized in that the second projection portion ( 6 ) on the upper layer has an overhang ( 6   a ), pointing towards the first projection portion ( 5 ).  
   
   
       3 . Roofing element according to  claim 1 , characterized in that the rear surface ( 8   a ) of protruding portion ( 8 ) is rounded off to form a multifaceted surface.  
   
   
       4 . Roofing element according to  claim 1 , characterized in that the material of the intermediate layer is a polyurethane and/or a polyisocyanurate foam.  
   
   
       5 . Roofing element according  claim 2 , characterized in that the surface ( 4   a ) of the intermediate layer adjacent to open space ( 7 ) has the same geometrical shape as surface ( 8   a ) of the protruding portion ( 8 ), such that surface ( 4   a ) can form a mating surface with surface ( 8   a ) of a second adjacent shape-similar element.  
   
   
       6 . Roofing element according to  claim 5 , characterized in that the surface ( 4   a ) of the intermediate layer adjacent to open space ( 7 ) and the surface ( 8   a ) of the protruding portion ( 8 ) are at least partly covered with the sheet material of the skins.  
   
   
       7 . Roofing element according to  claim 1 , characterized in that it contains at least one open channel ( 4   b ), running through the intermediate layer and connecting surfaces ( 4   a ) and ( 8   a ).  
   
   
       8 . Roofing element according to  claim 1 , characterized in that the sheet material comprises a metal sheet having a thickness in the range of 300-600 μm.  
   
   
       9 . Method of exterior sheathing a roof with a plurality of roofing elements as claimed in  claim 1  onto a previously provided roofing element support structure, comprising substantially of repeating the steps of positioning a first roofing element on the support structure, securing said element onto the support structure by attaching its first projection ( 5 ) onto the support structure, positioning a second roofing element by hooking protrusion ( 8 ) of the second element under a suitable angle under second projection ( 6 ) and into open space ( 7 ) of the first element, and rotating the second element into its final position, substantially coplanar with the first element, whereby the final position is intermediate a first final position, corresponding to an engagement of overhang ( 6   a ) of the first element with surface ( 8   c ) of protrusion ( 8 ) of the second element, and a second final position, corresponding to an engagement of rear surface ( 8   a ) of the second element with the front surface ( 4   a ) of the first element, where after the second element is optionally secured to the support structure by attaching its first projection portion ( 5 ) to the support structure.  
   
   
       10 . Method of exterior sheathing a roof according to  claim 9 , characterized in that the second element is positioned into the second final position by pushing it upward to engage its rear surface ( 8   a ) with the element.  
   
   
       11 . Process for the manufacture of a roofing element according to  claim 1 , whereby a mould is provided with two separable and heatable mould halves with at least one inlet port for accepting foamable material and at least one venting port to allow air to escape from the mould, whereby at least two layers of preformed sheet material are laid into the mould with their protruding portions outside of the mould and such that an intermediate open space to accept the foamable material is created between them, where after the mould is closed, the foamable material is injected into the mould, the foamable material is allowed to expand and harden, where after the mould is opened and the finished roofing element is removed.  
   
   
       12 . Process according to  claim 11 , whereby the volume of the injected foamable material is chosen such that its volume under free expansion is at least 5%, preferably 10% larger than the volume of the space to be filled by the foam material.  
   
   
       13 . Roofing element according to  claim 2 , characterized in that the rear surface ( 8   a ) of protruding portion ( 8 ) is rounded off to form a multifaceted surface.