Lumber Falling Case - J.D. Armstrong and Associates, Inc.

A customer at a home improvement store was shopping for rough-cut cedar boards. The 3/4" x 6" x 8' boards were stacked vertically in the lumber bin, and were reportedly packed in tightly. The plaintiff reported that he removed the first board from the bin and placed it on a lumber cart. He removed a second board from the bin and turned to place it on the lumber cart. As he was placing the second board on the cart, the remaining boards in the bin fell over on him causing injuries. There was a horizontal restraint bar approximately 8-1/2 feet above the board platform, above the top of the boards that fell on the plaintiff.

Jeff Armstrong was retained by the plaintiff's counsel to determine whether the boards could have fallen as described, and to determine what factors contributed to the lumber falling. Our investigation showed that the boards that fell were rather light and flexible. Each board possessed some warping so that when stacked vertically against each other, each board acted as a "spring" or a "bow" against the adjacent boards. With the boards stacked tightly in the bin, each board acting as a "spring" was slightly compressed, with the front boards holding the remaining boards in place.

We reconstructed the incident by stacking boards vertically, and determined that even when the boards were stacked at an incline there was a tendency for them to "spring apart" once the first boards were removed. It was determined that if the back board was placed less than approximately four inches away from the back of the bin that the boards could fall approximately two to four seconds after the front boards were removed, due to the decompression of the warped boards. Our recreation of the incident was video-taped and shown at mediation.

The plaintiff's description of the falling incident was reasonable and possible
Stacking the boards too tightly compresses them so that when the front boards are removed, the remaining boards can then decompress and fall forward.
If the boards are stacked with an insufficient incline they can fall forward