By Andrea Jeffery, P.Eng.

Product failure is not uncommon and is usually more of an annoyance than a serious issue. However, sometimes products fail and result in serious damage or injury. These are often the product failures that warrant investigation and analysis to identify any potential subrogation opportunities. Causes of these failures are typically due to one of three issues: installation, manufacture or misuse.

Failures due to installation

One of the reasons products fail is improper installation. This is particularly common for products that have manufacturer specific installation requirements. A failure to follow these installation instructions can result in the products failing under normal working conditions or not functioning as required.

Overtightening or under tightening. This can lead to a threaded component fracturing or parts pulling apart. This is often seen in plastic coupling nuts (common on toilet supply lines), which are often only hand tightened. When wrench-tightened, excessive forces can be placed on the nut causing it to fracture and break. Under tightening is a common issue in compression fittings. If not tightened sufficiently to maintain a grip on the pipe under pressure, they may work themselves loose over time.

Using the wrong component for the job. Components are rated for specific working conditions including temperature, pressure and chemical compatibility. Installing components that don’t meet the required working conditions can result in premature failure. Tubing rated for a maximum operating pressure of 55 psi should not be used for potable water purposes, because supplied water pressures are often 60-80 psi. To make it more confusing, tubing rated for different pressures can look the same, for example, refrigerator and ice maker supply lines look very similar to lower rated vinyl tubing which is not suitable for this purpose.

Missing a step. Often multiple systems in a building work together to meet the required function. If one of these steps is missed or not properly done, it can negatively impact other systems in the building. An example of this is inadequate building insulation; if parts of a building are not properly insulated, particularly exterior walls, water pipes running in or adjacent to the walls can freeze.

Failures due to manufacture/design

The manufacturer is another party that may be held responsible for product failure. The manufacturer is ultimately responsible for ensuring their product is suitable for its intended use, made properly without significant defects, and is safe. The manufacturer is also responsible for providing adequate information regarding proper use, installation and maintenance to the installer and user.

Material Selection. In the same way that installers can select the wrong component for a job, sometimes products are made with a material that makes them inherently unsuitable. It is the responsibility of the manufacturer to ensure the material the product is made from allows it to function as intended. As an example, fittings manufactured for use on potable water systems must be made with dezincification resistant brass, or a different material, to prevent the fitting from becoming brittle and prone to failure. This is because the composition of certain types of brass allows the zinc to be selectively leached from the fitting when in contact with potable water, a process called dezincification.

Manufacturing process. The process used to manufacture a component can sometimes lead to defects and cause (or contribute) to product failures. Temperatures during casting and moulding are one example of this; if the temperature is not maintained throughout the manufacturing process, material may prematurely cool forming seams in the product. These seams are often weaker, and areas of stress concentration, which can lead to failure. Porosity and inclusions are other common process issues that can lead to product failure.

Product design. Sometimes a product is manufactured correctly as per the manufacturer’s specifications, but due to issues with the product design, it is prone to failure or hazardous. Some examples of this would be thin wall sections, sharp edges that create stress concentrations and insufficient safety measures (lack of or improperly placed safety switches).

Failures due to misuse

Maintenance. Numerous products require a little TLC from time to time. Improper maintenance, or lack of maintenance, can cause products to stop working or fail. Some components such as filters require regular cleaning or replacement to function properly. Without this, build-ups of dust and debris can lead to overheating, sometimes resulting in operational issues or fire. Other systems, such as dry sprinkler systems, require annual draining to prepare for freezing temperatures. A failure to drain a dry sprinkler system will often eventually lead to water collection, freezing and, ultimately, failed pipes and fittings.

Inflicted damage. When used outside their design limits, products fail. Often these failures are accidental or due to negligence. Hanging clothes off sprinkler heads is one example of this type of failure. Sprinkler heads are not designed to hold weight and can fail catastrophically if used as a coat hanger. Other examples of inflicted damage failures are a relatively brittle material (such as a toilet bowl) being struck with a tool or nails perforating flexible water supply line.

Regardless of the product failure, CEP Forensic can assist in determining the cause and contributing factors to help our clients determine who is responsible. Our engineers are well equipped to document the site and failed components, review applicable codes and standards, as well as perform any testing that may be required to get to the root of the issue.

If you have any questions or would like to learn more about this topic, please contact our Materials Engineering team at 877 686-0240 or

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