Faulty Plywood: Failure Analysis & Quality Testing

One of the first cases I was ever involved with was regarding high-quality timber doors that had been installed in a premier shopping mall. Shortly after installation, the paint on the doors began to peel, and the joinery who had performed the installation was forced to replace the doors at their own cost.

The joinery had ordered door blanks of marine-grade ply for the installation. When the joinery examined the doors that were removed, they became suspicious of the quality of the product they received. I was given samples of the door, and began testing them in accordance with EN 314. The samples are cut in a specific manner to expose the glue-line joining the layers of the ply, and are then immersed in boiling water for 48 hours. After immersion in the boiling water, the samples are extracted, dried, and subjected to tensile testing. The quality of the ply is then graded according to the tensile force required to break the sample, and the percentage of cohesive failure within the wood.

However, these door samples didn’t even make it tensile testing. When I took them out of the boiling water, the plys of wood simply fell apart. It was evident that this “marine grade” plywood was in fact a run-of-the-mill plywood. I prepared a technical report on my findings. The photographs of the disassembled plies floating in the boiling water put the matter beyond doubt.

A settlement was agreed between the joinery and the ply supplier. The joinery was reimbursed for their expenses, but more importantly, their reputation was restored. 

Do you have an issue with the quality of a product you’ve received, whether it be wood-based, metal-based, plastic-based, electronic or textile? Contact us today!