Patent ID: 7592059

Claim:
A composite structural element comprising: a hollow flame made from a rigid material, said hollow flame having an interior, and an exterior, wherein the hollow flame is an elongated rectangular box, and wherein the hollow flame further comprises: a single U-shaped section comprising: an open side; a closed bottom surface; a first arm; and a second arm substantially parallel to the first arm, the first arm and second arm connected with and perpendicular to the closed bottom surface; a top section positioned over the open side substantially parallel to the closed bottom surface and joined with the first arm and the second arm; a first flap which is an extended portion of a first end of one of the first arm, the second arm, and the closed bottom surface, and bendably correspondingly connected with the first end of one of the first arm, the second arm, and the closed bottom surface, the first flap bending into position to cover and seal the first end of the hollow frame; a second flap which is an extended portion of a second end of one of the first arm, the second arm, and the closed bottom surface, and bendably correspondingly connected with the second end of one of the first arm, the second arm, and the closed bottom surface, the second flap bending into position to cover and seal the second end of the hollow frame; a polyurethane foam that reacts and becomes rigid in the interior such that the polyurethane foam completely fills open portions of the interior; and a substantially uniform high-solid protective coating provided over the exterior of the hollow frame.