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  • Writer's pictureCorey Menscher

The Best Locations for Leak Sensors in Multi-family Buildings

Updated: Aug 17, 2022




Automated leak detection is a proven way to prevent water damage and losses in homes and buildings of any size. Multi-family buildings have compounded risks due to their multi-story nature and the diversity of their occupants' home designs. Whenever there are upstairs neighbors involved, the likelihood of catastrophic damage from water leaks is almost a certainty.


But where, exactly, do these leaks originate? Where are the highest risks? That depends on the age, design, and materials of the structure in question. In this post, we will break down the most common high-risk locations throughout multi-family buildings, based on our experience in protecting homes and businesses from water damage.


Building staff only learn of these incidents when neighbors observe evidence of water damage from their ceiling or walls. By the time they are notified, significant damage has already been done.

HVAC Systems


HVAC systems in multi-family buildings can come in a variety of forms, and nearly all of them handle water in some way. Whether it's steam radiators, PTACs with condensation pans, or closed-loop hydronic systems...damage can occur when these systems discharge water that unexpectedly overflows pans and drain lines, cascading down walls and through ceilings.


The primary culprits of damage are condensation lines that clog, backing up the only place for the water to go, but pinhole leaks and malfunctioning traps can also be to blame. The result is a slow and steady flow of water in a location that is not easily observable. Building staff only learn of these incidents when neighbors observe evidence of water damage from

their ceiling or walls. By the time they are notified, significant damage has already been done.


Leak sensors whose probes can be placed by condensation lines, near the lips of condensation pans, and under valves can detect and notify building management of water discharge within seconds. By specifically communicating which apartment, HVAC appliance, and the location of collected water, staff can be dispatched to the source of the problem. This avoids the long and drawn out search-and-repair process that accompanies a frantic call from a neighbor below.


Bathroom Fixtures and Appliances


Toilet speedy valves fail often, especially if they aren't exercised regularly. Some toilets use plastic pipes feeding water from the main line into the bowl. While less expensive, these lines are prone to degradation and cracking if not replaced regularly...a task that is often overlooked. Even well-maintained toilets can exhibit problems from both source and waste lines. Placing a leak sensor near the base of a toilet can save the day, but be sure your sensor is small enough to be situated behind the bowl, where mops and stray sink, shower, or tub water won't cause a false positive. Our modular Droplet Duo™ two-probe sensors are small enough to fit behind the tightest space, and are easily hidden from view.


Bathroom sinks can suffer leaks as well, often inside vanity cabinets, where they go unnoticed for hours or even days. A leak sensor placed inside can eliminate these situations from occurring, giving tenants peace of mind.


Kitchen Fixtures and Appliances


Kitchen sinks, like bathroom vanities, also suffer from obscured leak conditions. Clogged P-traps can result in water flowing into the sink cabinet, and the homeowner may have no idea it is happening. Other fixtures such as automatic hot-water dispensers and premium faucets with attached hoses have many potential failure points. Placing a leak sensor inside a kitchen sink cabinet can warn tenants and staff of an impending situation within seconds.


Dishwashers are another source of potential damage. Most modern dishwashers have built-in leak detection for their internal pans, and will shut off if they suspect an issue. But these sensors can not detect whether there is an issue along the supply or drain lines, so they are not sufficient to protect from the most damaging incidents. Fortunately, dishwashers tend to be installed right next to kitchen sinks. If you use a two-probe moisture sensor, such as the Droplet Duo™ by Perceptive Things®, you can install the second probe underneath the washer to detect pooling water. You won't need to purchase and maintain an additional sensor. You get two sensors in one!


Ice makers are the final troublemaker of the kitchen. These appliances use thin copper or plastic water lines, which can fail after a few years. The water lines connect at the back of the refrigerator, too. If a leak occurs within the ice making system, it won't be easily observable. You'll likely hear about it from the neighbor downstairs before the tenant notices anything wrong! A leak sensor under the refrigerator can easily solve this problem.


Leaks are especially insidious for sinks that rest in cabinets, as they often go unnoticed for hours or days.

Clothes Washers


Clothes washers have hot and cold intakes and a single drain. Many buildings today require the entire unit to be placed in a pan, with a sensor tied to automated valves on the supply lines. If the sensor detects water in the pan, the supply is cut and disaster is averted. Or is it? Leaks from the fixtures can happen such that the water drains down the wall, outside of the pan. Plus, even when the supply is shut, building staff may not ever become aware of the issue since there is no communication aspect of these shutoff systems. Tenants who rarely interact with the shutoff system become confused when the valve is closed. They arrive to find an inoperative appliance and no understanding as to why it will no longer function. The result is a support call to building staff, who will reset the system for the tenant. This is an inefficient process, and can frustrate both the tenant and the staff.


A more proactive approach is to install a supplemental moisture sensor that can notify tenants and staff that a leak was detected. This will ensure all parties will have situational awareness...the tenant can check on the situation if they are home, and if not, the building staff can make courtesy visit to ensure no water discharge is threatening damage to the affected apartment, or any neighbors below.



Building Mechanicals


Depending on size, amenities, and water-using systems, there are many points within a building's infrastructure than can lead to significant losses if discharge of water occurs with no warning. Failed sump pumps, compromised boilers and tanks, and leaking air handler water lines can all be responsible for large amounts of water escaping. Detecting water in these locations, that do not usually see high foot traffic, is critical.


Simple single-point leak sensors can do the job for many of these locations, but sometimes you need a more industrial approach. Our Droplet Pro™ leak sensors are IP-68 rated devices that employ a 10 foot liquid-sensing rope sensor which can be stretched over long linear areas (such as along a wall), surrounding a piece of equipment, or snaked to cover a large footprint. If water comes in contact with any point along the entire rope's length, staff will known within seconds.


Don't rely on a daily walkthrough to report anomalies when you can have connected sensors watching for a potential situation 24 hours a day, 7 days a week!

Building Amenities


Building amenity spaces are also high-risk areas, where leaks can cause enough damage to close them down due to the need for repair, such as gyms, locker rooms, and party rooms with kitchens. Sensors strategically placed near fixtures and appliances in these areas can eliminate the risk of damage and closures, elevating your service level.


Tenant storage lockers are also high risk areas. Irreplaceable valuables sit unprotected in the basement, where all water eventually travels. These storage rooms can go days without anyone accessing them, so it is a good idea to install leak sensors at multiple points throughout the area.


Finally, and somewhat obviously, pools are a major potential risk. If designed properly, damage from failing pumps, water lines, and other pool systems will be defended against through architectural engineering. But no amount of waterproofing will alert building staff of a potential situation. Moisture sensors installed at strategic locations under pools systems can provide critical notifications that an incident has occurred. The earlier such information can be delivered to staff, the less damage will occur. Don't rely on a daily walkthrough to report anomalies when you can have connected sensors watching for a potential situation 24 hours a day, 7 days a week!


The bottom line is that an effective sensor network is a building-wide system that is installed and maintained by building operations personnel.

Managed Services Are Best


If you follow the recommendations above, you will go a long way to mitigate the risk of water damage from leaks. But you may be wondering how you can be expected to install internet-connected sensors in all of these locations throughout your entire building. Should you buy a bunch of WiFi or Zigbee products you can find on Amazon? The answer is a resounding NO.


We have dedicated an entire blog post to this issue, but the short version is that scaling consumer products to an entire multi-family building is fraught with peril. These products are not designed for large-scale centralized management, and installing even just a handful of them will result in substantial work to maintain the fleet. Considerations such as internet connectivity (Whose WiFi will they connect to? Who manages passwords?), installation and configuration (How much extra time goes into getting each and every system online?), general maintenance and security updates (Who is notified of downtime? Low batteries? Who performs security updates?)...these are just a few of the issues your staff will be confronted with on a continuous basis.


You may now be thinking, "Why don't we just ask or require owners to install their own?" Handing the installation and management of these sensor systems over to tenants and owners is risky. There is no way to ensure that sensors will be installed and maintained properly, or if they are even installed at all! We have come across buildings that have tried this, and there are plenty of stories where tenants' own actions resulted in alerts never reaching staff. The bottom line is that an effective sensor network is a building-wide system that is installed and maintained by building personnel. You would never hand off the maintenance of elevators or cooling towers to a tenant, so why a sensor network?


Managed services like Perceptive Things® take the work out of maintaining a fleet of dozens, hundreds, or even thousands of sensors. The health of the network is constantly monitored, and issues can often be addressed without the need for staff intervention. Once the Perceptive Things® network is installed, each sensor is pre-configured for your building. All you have to do is make note of where the sensor is situated, and the rest is managed from our cloud platform.


Our goal is to make deploying and running a building-wide sensor network simple and cost-effective. Contact us today to discuss how we can protect your building!

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