the present invention provides a reinforced plastic laminate structure comprising an elongated reinforcing material that is encapsulated by an extruded plastic material that forms a continuous structure around the reinforcing material . the present invention contemplates methods of extruding a tube of plastic material while simultaneously introducing a reinforcing material within the interior of the tube . thereafter , the tube is flattened so that the interior wall of the tube comes in contact with the reinforcing material to encapsulate the reinforcing material in a continuous structure . the reinforced plastic laminate sheet is made from an apparatus an extruding machine for extruding plastic with an annular die and opening for the extruding tubing . attached to the extruding machine is a mandrel which feeds a reinforcing material into the center of the annular opening . pressure rollers flatten the tubing after it exits from the annular die . the reinforcing plastic material may be formed into a variety of useful products where increased strength is required . the ease of manufacture provides a cost advantage over conventional construction materials .