Construction material containing expanded flexible material

Abstract

A construction material such as an insulating roofing material is prepared by slitting a sheet of flexible material, such as cardboard, plastic, or metal foil, to provide discontinuous slits in spaced apart parallel lines, and then stretching the slitted sheet to produce a three-dimensional cellular configuration. The cells thereof are then filled with melted tar and aggregate, such as sand, and then cooled to provide a layer of construction material.

What is claimed is:  
     
         1 . A construction sheet material comprising (a) a cellular expanded sheet of material formed by longitudinally stretching a sheet of flexible material having discontinuous slits in spaced apart parallel lines, and (b) a filler material comprising aggregate and tar filled in the cells of said cellular expanded sheet.  
     
     
         2 . The construction sheet material of  claim 1  wherein said flexible material is cardboard.  
     
     
         3 . The construction sheet material of  claim 1  wherein said flexible material is plastic.  
     
     
         4 . The construction sheet material of  claim 1  wherein said flexible material is metal foil.  
     
     
         5 . The construction sheet material of  claim 1  wherein said aggregate is sand.  
     
     
         6 . A method of producing a construction material comprising the steps of slitting a sheet of flexible material to provide discontinuous slits in spaced apart lines parallel to each other, stretching said slitted sheet to produce a three-dimensional cellular configuration, filling the cells thereof with a mixture of melted tar and aggregate, and subsequently cooling said material to produce a hardened layer of construction material.  
     
     
         7 . The method of  claim 6  wherein said flexible material is cardboard.  
     
     
         8 . The method of  claim 6  wherein said flexible material is plastic.  
     
     
         9 . The method of  claim 6  wherein said flexible material is metal foil.  
     
     
         10 . The method of  claim 6  wherein said aggregate is sand.  
     
     
         11 . A method of providing a construction material comprising the steps of producing a compact roll of a continuous sheet of unexpanded flexible material having discontinuous slits in spaced apart lines parallel to each other; transporting said roll in compact, unexpanded form to a site of usage; unrolling and stretching said continuous sheet to provide a three-dimensional cellular material; and filling the cells of said cellular material with a mixture of melted tar and aggregate.