Load-bearing structures

A load-bearing structure comprising

• a molded structure comprising a first skin structure covering a face of a first plurality of generally vertical walls forming a first plurality of shaped hollows which have an opposing face, and
• a molded structure comprising a second skin structure covering a face of a second plurality of generally vertical walls forming a second plurality of shaped hollows which likewise have an opposing face,
• joined together with the opposing faces in contact at a joining line formed by said first plurality of generally vertical walls and by said second plurality of generally vertical walls, said opposing faces being otherwise uncovered, to form a cellular core derived from said first plurality of shaped hollows and from said second plurality of shaped hollows, and sandwiched between and covered by said first and second skin structures,
• wherein the walls forming said cellular core include a plurality of cell-connecting apertures adjoining said joining line.