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Specifying Plumbing Leak Detection

Take these steps to protect your clients from the destructive effects of leaking water.

This article appeared in the September 2018 issue of Plumbing Engineer magazine.

By Kathleen Anthony
Product Manager, Reliance Detection Technologies

Download a PDF of this article from Plumbing Engineer.

Plumbing leaks contribute heavily to nearly $10B in homeowner water damage insurance claims each year. [1] Water damage is also the leading cause of property damage in offices, apartments and other real estate facilities. [2] But why would your building be at risk? Your design is sound, your contractors are experts, and your equipment is top notch.

The short answer is that leaks are inevitable. They are not a reflection of design, quality or workmanship. Plumbing fixtures, joints and water-fed appliances are simply prone to failure over time. And when minor leaks go undetected for hours, days, or even weeks, the resulting property damage can turn catastrophic – especially in common-risk commercial, residential or office buildings.

As water damage has emerged as a leading source of claims, insurance companies are increasingly offering discounts for properties that employ plumbing leak detection, or even mandating that systems be installed if a claim has been paid out in the past or a property employs high-end finishes. Plumbing engineers and architects have also been driving adoption of leak detection as value-added engineering on their projects, and forward-thinking mechanical contractors and property owners are also helping make plumbing leak detection a more mainstream technology.

A burst washing machine hose can release 650 gallons of water in a single hour. A plenum water heater can leak for days, and no one will know until the ceiling collapses. Dishwasher leaks in residences and breakrooms can go undetected for weeks, causing mold issues in addition to water damage. In a commercial building that is unattended over the weekend, a burst pipe can lead to ankle-deep water come Monday morning. Undetected slow leaks can lead to skyrocketing utility bills. Water can quickly spread and displace multiple tenants, damaging a building owner’s reputation and requiring them to deal with expensive insurance claims or even loss of coverage.

These are real problems that your clients face every day, and you are in a unique position to recommend proactive measures that can protect them.

The good news is that specifying leak detection technology does not have to be a frustrating or complex process. Solutions are available for even the most challenging spaces, from covering large facilities to monitoring within plenums.

Dental offices are at particular risk due to leaks at water-fed dental chairs/cuspidors. When offices are located on upper floors of buildings, the water can quickly flow down or sideways to engulf adjacent offices. Leak detection sensors and alarms can alert technicians or building security of a leak before it has a chance to disrupt office schedules and patient access.

Identify the Risks

Leak detection is a simple concept, but it is by no means a one-size-fits-all deployment. The first step in choosing a solution for any given project is determining the potential leak risks that are in play.

What water-fed appliances and general plumbing layout do you need to monitor? Is there mission-critical equipment, data, or priceless possessions that need to be protected? Are there tenant-related concerns that could lead to water-related problems, such as in a memory care or assisted-living facility? Are you dealing with a medical facility with many sinks or equipment using water filtration, such as dialysis machines? Is reducing water waste or consumption a critical concern to the building owner?

What’s the Desired Outcome?

Once you’ve identified what you need to monitor, determining the desired outcome when a leak is detected is critical in specifying the best technology for the job. You should consider things like: who is using the water sources in question; what are the ramifications of shutting off the water supply; and what is the potential impact of water damage mitigation activity on tenants, residents and building owners?

This information will help you determine what type of response you require from a leak detection system. Is a simple audible alarm sufficient to alert people of a leak, or do you also need to automatically shut off the water supply to an individual appliance, entire office/apartment, floor, building section, or even to the entire building? Is automatic notification of a leak required via text message, email or smart phone/tablet app? Do you need to tie in notifications to a building management or security system?

There are many potential leak points to monitor in break rooms, from sinks and refrigeration lines to feed lines for beverage dispensers and coffee makers. In commercial spaces, there may only be access to the water feed line above the drop ceiling. A shut-off valve can be installed in the plenum, with the alarm box and water sensor(s) below.

System Design, Operation & Maintenance

After determining the desired outcome during a leak event, system design, operation and maintenance considerations will help you choose which product to specify. You’ve already identified the potential water shutoff points. Here are some of the other system-related considerations you should take into account:

  • For retrofit/refurbishment projects, is there access to the piping in the desired shutoff locations? Is there enough physical space to install the shutoff device in the desired location?
  • Is electrical power required and available in the location?
  • Do you need to account for plumbing or appliances located in plenum spaces?
  • What pipe and valve sizes are you working with? You will find that some mitigation systems offer limited valve size options.
  • Valves must be rated for potable water (drinking water), adhering to both NSF/ANSI 61 and NSF/ANSI 372 to meet the current Federal Safe Drinking Water Standard.
  • Are battery-operated components acceptable to the client/tenant? Will there be easy access to such components to change the batteries?
  • What happens to the system when power is lost? Will the valve automatically close, and is that a positive or negative for the client/tenant?
  • How will the system be reset if the valve is located behind the wall?

Typical point-of-contact leak detection application on a water heater/tank. The shut-off valve installs on the water feed line, and a water sensor rests on the substrate under the tank.

Point of Contact vs. Flow

Your final major consideration is the technology driving the system you specify, and you will usually encounter two options: point-of-contact or flow.

A point-of-contact system typically uses conductivity sensor(s) to detect a leak. Sensors are deployed in areas where water is likely to first accumulate in the event of a leak – inside a pan or on the floor/surface. Water must come in contact with the sensor to activate the system, which may or may not include a valve to automatically turn off the water feed. Point-of-contact technology can support a wide range of valve sizes and incorporate many different sensor types and accessories to accommodate a wide range of applications. Since sensors are deployed in specific locations, and wireless sensors are often addressable, it is typically easy to identify leak origination points. These systems do require that you do a good job predicting where water may accumulate, and there are more steps involved in system installation than with flow monitoring solutions. Depending on the facility, loss of unsecured sensors can also be a concern.

A flow monitoring system is installed directly on the water line. It constantly monitors usage, using preset triggers for volume (low, medium, high usage) or time (for example, 30 minutes of continuous flow before shutoff), and it may or may not include a valve to automatically turn off the water feed. With no external sensors, flow technology is very discrete, and it can offer additional valuable data on overall water usage. Flow systems are typically only available for ¾” and 1” pipes. Installation can require significant feedline access, complete system drain-down and purge, and the like. The biggest challenge of using flow monitoring for leak detection is that it offers little indication of where a leak may be originating from. False alarms can also occur from simple changes in behavior or usage patterns.


Plumbing leaks are a simple fact of life, but the damage caused by them is almost completely preventable.

Building owners, tenants and industry forces are realizing the benefits of proactive leak detection and water damage mitigation systems – preventing business and homeowner disruption, property damage, additional claims from other needed remediation such as mold, loss of data and human life, and water conservation.

Leak detection specification is straightforward as long as you understand the desired outcomes, system design considerations and decision points. RDT offers solutions for every space and budget. Feel free to contact us to discuss your application!




Author Bio

Kathleen Anthony is the Product Manager for Reliance Detection Technologies (RDT), an industry leader in point-of-contact commercial and residential plumbing leak detection and automatic water shutoff solutions. She has more than 9 years of experience helping engineers and mechanical contractors specify the best solution for their application, no matter how unique.