Construction Defect Analysis, Window Damage

California Failure Analysis Expert Witness performs a glass failure analysis on defective tempered glass windows installed in a public building. One of the construction defects was window scratching. Representative windows were removed and sent to the Read Consulting California failure analysis lab. This allowed a detailed investigation of the window defects. The failure analysis determined that the scratches were caused by post construction cleaning. Upper left is a macrophotograph of a typical set of scratches. Their parallel nature shows them to have been caused by a metal scraper. Upper right is a 40X photomicrograph of a scratched region. These scratches were in the glass. There was no coating on the scratched surface.  

Manufacturing Defect on Tempered Glass Window

Glass failure analysis expert witness performed a root cause failure analysis on window defects found on a recently built custom home. The upper left photograph shows the defect from the building exterior. The window defect resembles a dust or dirt streak and was not detected until the post construction window cleannig. In all cases, the manufacturing defect is in the center of the window, is parallel to the long side and it looks like a streak or scuff. The upper right photograph is a 200X photomicrograph of a portion of the window defect. It is composed of an array of small glass particles strongly adhered to the glass surface. It is believed that these particles were generated during the window sizing process and were a contaminant on the horizontal rollers used in the glass temper process. During glass tempering they came into contact with the hot glass surface and welded to it. This is a manufacturing defect. It is not a construction defect. This defect is often blamed for window scratching from window cleaning operations. However, these particles were visibly obvious and could not be dislodged. Therefore, these particles don't fit the popular window damage model proposed by many window cleaning experts.

Glass Expert Discusses Construction Defect

Glass expert analyzed a failed shower enclosement wall made from tempered glass. The failure occured before the homeowner warranty had failed. The contractor refused to replace the glass panel. It was his opinion was that the homeowner had damaged the panel and was responsible. Glass failure analysis determined that the failure initiated under the frame. In addition, there was no damage to the metal frame (i.e. there were no "dings" or "dents"). Therefore, the panel had failed spontaneously as was claimed by the homeowner. The upper left photograph is an overview of the failed panel. Here one can see that the failure emanates from the lower right corner. The upper right photograph is a close up of the corner. As a result of the analysis, the contractor agreed to honor the warranty and replace the tempered glass panel.