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Testing Home Builders’ Knowledge of Residential Plumbing Systems

March 23, 2022
While few home buyers ask about the pipes and fittings hidden behind walls, they can have a huge impact on the health and reliability of a new home.

By Jonathan Simon

Choosing the right materials—and ensuring they are installed correctly—is essential to building healthy and reliable homes. Yet, with the range of materials in today’s homes, it can be difficult for builders to be experts on all the materials available to them.

Some materials do, however, have a greater impact on quality and represent a greater risk than others. One of those is the material selected for the plumbing system. While few home buyers ask about the pipes and fittings hidden behind walls, they can have a huge impact on the health and reliability of a new home. Whether materials are selected by an engineer, the plumbing contractor or the builder, the liability for premature failures is most likely to rest with the builder. While it may be tempting for builders to delegate plumbing material selection, they should take steps to minimize the risks of poor material choices.

To get a better sense of builders’ understanding of those risks and identify potential blind spots when dealing with residential plumbing, Lubrizol Advanced Materials, manufacturer of FlowGuard Gold® CPVC, developed an online quiz that was completed by more than 300 builders. Their responses demonstrated a good knowledge of many potential risks, but also exposed some gaps in understanding that could prove costly.

The Warranty Says What?

The biggest blind spot uncovered by the quiz involved the amount of protection builders can expect from the warranties on some plumbing materials. A majority thought the statement, “Some plumbing piping warranties can be voided by drinking water” was false. It is actually true.

Plumbing materials that are vulnerable to corrosion and degradation from the disinfectants used to ensure drinking water is safe for human consumption may include clauses in their warranty that void the warranty when chlorinated water enters the pipe. A periodic review of the warranties for the products used in major systems such as plumbing can help ensure builders understand what’s covered and where they may be exposed to having to absorb costs because of broad exceptions to the warranty such as this one.

The Cost of Failure

Another question that had a high percentage of incorrect answers asked participants what product category had the largest product defect settlement (class action suit) in U.S. history. Forty-six percent selected drywall, 16% concrete and 6% flooring, meaning more than two-thirds answered incorrectly. The correct answer was plumbing and pipe fittings, specifically the billion-dollar settlement reached over the widespread failure of polybutylene piping due to chlorine degradation.

There are two reasons this shouldn’t come as a surprise. First, plumbing failures aren’t just inconvenient; they can also be expensive to deal with. It isn’t only the plumbing that needs to be replaced, often through a complete repipe, but also water-damaged drywall, flooring and cabinets. The costs of a plumbing failure can add up quickly.

In addition, plumbing failures don’t always occur right after the homeowner takes possession. Because of the gradual nature of the effect of chlorine on polybutylene, it took years for the incompatibility of that material with chlorinated water to become obvious. By the time the defect was exposed, the material had been installed in hundreds of thousands of homes.

Protecting Water Quality

Delivering a healthy home is increasingly important and, while 100% of builders recognized indoor air quality as an important component of a healthy home, 30% missed the importance of water quality, which can be impacted by the plumbing materials selected. This may be because no plumbing material can improve water quality, but different systems do introduce different risks to the water supply. Builders that want to deliver the highest possible water quality should focus on the performance of plumbing materials in three areas:

·      Biofilm growth potential: Biofilm can grow in residential piping systems and, in addition to being unpleasant, can foster dangerous bacteria that carry disease. Different plumbing materials have different biofilm growth potentials, which is the rate at which biofilm will form in the pipes. Choosing a material with a low biofilm growth potential can minimize risk.

·       Leaching: Materials also vary in their susceptibility to leaching, in which chemicals from the pipe can enter the water supply. NSF 61 is a performance-based standard that evaluates the amount of contaminants that leach from plumbing materials into the drinking water. For healthy homes, choose materials that are NSF 61 certified under all water conditions.

·       Permeation: Permeable piping materials can allow hazardous chemicals such as pesticides that come into contact with the outside of the pipe to seep into the water supply. Vinyl materials, such as CPVC, are considered virtually impermeable and represent a better choice for homes to minimize the risk of chemical permeation.

Accepting Responsibility

Over 90% of the builders taking the quiz understood they were responsible for product performance.

Builders also understood the limitations of building codes in dealing with problem materials. Ninety-two percent correctly answered “false” to the question: “Federal, state and local building codes have taken all problem materials out of the market; thus, any product that is available is deemed to be safe regardless of where it is being used.” As we saw with polybutylene, it can take years for defects in a product to become widespread enough to be restricted by code, particularly in the case of plumbing materials that can’t hold up to local water conditions.

A lower percentage (62%) recognized that just because a home passes inspection doesn’t necessarily mean it was built properly. The drop-off in awareness of potential liability issues got even steeper regarding the extent of the protection provided by licensing regulations. Only 56% understood that state and local licensing requirements, while important, do not ensure homes are built correctly by qualified workers.

Complying with codes and using properly licensed subcontractors is essential, but mere compliance doesn’t ensure quality and long-term performance. If the wrong materials are selected for critical systems such as plumbing, the quality of the home will be compromised.

Builders may not be able to be involved in every decision made during the home building process, but one that does require their attention is plumbing material selection and installation. Working closely with plumbing contractors and piping material manufacturers, builders and contractors need to understand the risks associated with the materials selected and take steps to reduce their risk exposure and deliver on home buyer’s expectations.

Jonathan Simon is the North American residential plumbing manager for Lubrizol Advanced Materials Inc., the parent company for  For 60 years, FlowGuard Gold Pipe and Fittings has provided reliable hot and cold water plumbing systems to residential and commercial buildings.FlowGuard Gold Pipe and Fittings.

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