Product Failure Analysis: Consumer Product Affected by Inappropriate Raw Material


Soon after roofing shingles were installed, the shingle manufacturer received complaints from numerous homeowners who observed rust-colored staining discharging from the shingles. The manufacturer replaced the shingles and began an investigation into the cause of the discoloration. Their in-house testing using an industry-standard method revealed the presence of corrosion-susceptible particles that were thought to be the cause of the staining. These particles were discovered in the raw material of a product used on the shingles. The test results prompted the manufacturer to file a lawsuit against the raw materials supplier.

The expert retained by the raw materials supplier issued an opinion that contradicted that of the manufacturer. Their expert reported that the corrosion on the shingles was not caused by the supplied material but rather due to the presence of microscopic mineral particles in another component of the shingle – the sand – which they did not supply. The manufacturer of the shingles retained RJ Lee Group experts to conduct materials failure analysis to determine the root cause of the rust-colored staining.

RJ Lee Group experts used multiple failure analysis techniques, including optical and scanning electron microscopy to investigate the shingle material. We performed a detailed examination of the raw materials for both shingle components as well as of uninstalled shingles from inventory and those from complainants’ homes. We discovered that a portion of the supplied raw material contained corrosion-susceptible material that we determined was the source of the problem. The corroding particles at the top of the shingle became dislodged and migrated to the bottom of the shingle where they would occasionally become embedded and continue to corrode. Although exacerbated by the environment, our failure analysis of the product helped determine that the root cause was not the rain and humidity, but rather the raw material that easily corroded. The presence of mineral particles in the sand was shown to be inconsequential despite the opposing expert’s opinion.

As a step towards further resolution, all parties, including attorneys and experts, met at the manufacturer’s facility so everyone would have access to all of the samples. RJ Lee Group’s expert conducted “real-time assessments” of the samples using a field deployable optical microscope brought to the facility. RJ Lee Group prepared and submitted an expert report of its findings after which our client informed us that they had reached a settlement.