Causes of Tire Failure: Belt Separation

According to a National Highway Traffic Safety Administration survey, nine percent (9%) of vehicle collisions involved vehicles that had issues with the tire prior to the collision. Issues included tire tread separations, blowouts, bald tires and underinflation. See NHTSA Crash Causation Survey at This post will look at common causes leading to tire belt separations.

Generally speaking, a separation in a tire consists of an area of no adhesion between two adjacent tire components. These components are designed so that they completely adhere to each other. Separations often result when pressurized air within the inner liner of the tire is allowed to pass through the liner and enter into the structure of the tire (commonly referred to as intercarcass pressurization). Once inflation pressurized air enters the structure of a tire, it can migrate along and through the body cords and belt cords of the tire.

Intercarcass pressurization is a dangerous condition because it can cause tire separations and blowouts. Once the air is allowed to pass through the liner and into the structure of the tire, the pressurized air can mechanically force components apart. These components of the tire are not intended or designed to be subjected to highly pressurized air.

As pressurized air migrates through the inner liner of the tire, the air can slowly move through and around the tire. This allows separations to occur in almost any location throughout the tire, or in multiple locations. Multiple separations can also grow large enough so that they connect with other separations, increasing the size of the overall area of separation.

Separations within a tire can lead to catastrophic collisions. Often, the separations result from defect design or manufacture of the tire (or both). Florida, like other states throughout the United States, allows victims of defective tires to sue for damages under multiple theories of liability, including negligence, strict liability and breach of warranty.