Important Water Damage Information for Property Owners & Managers
Water damage to a commercial building or high-rise could mean significant expenses, downtime and a protracted recovery process. Knowing the ins and outs of water damage can help property managers identify problems before they become disasters.
Special Considerations for Commercial Buildings
Commercial buildings have some key differences from single-family homes. One of the most basic differences is the sheer size of the building. Commercial spaces can range from individual storefronts to high-rise apartment buildings to warehouses spanning hundreds of thousands of square feet. The larger size of these buildings can mean an increased volume of water demand and can make it more difficult to spot small problems before they become big ones.
When water leaks, gravity will pull it toward the ground through any free path the water can find. Depending on the construction of the building and the location of the leak, this could be straight down through a wall cavity or elevator shaft, or it could be across a ceiling space and into other, more distant parts of the building. The larger a building is, such as a high-rise, the more complicated it could be to locate, stop and repair a major leak.
Most leaks and damage are preventable, but a property manager needs to be aware of the most common causes and how to address them. Here are some of the most common sources of water damage in commercial and high-rise buildings:
- Plumbing clogs
- Pipe leaks
- Inefficient appliances (washing machines, dishwashers) stressing the system with high water demand
- Poor implementation of safety valves
- Bad plumbing habits, including flushing inappropriate materials and using caustic chemicals to clear clogs
- Natural disasters such as storms and floods
Categories of Water Damage
When it comes to water damage, there are three categories to know. These categories are based on the source of the water and the potential for harm that it carries.
- Category 1: This is water that has come from a source such as the clean water supply in a building. If addressed within 24-48 hours, most Category 1 water poses a low health risk. However, even clean water can begin to cause mold in as little as 48 hours.
- Category 2: This category is known as “gray water.” This water comes from sources that could have mild to severe contamination, including fire suppression systems, treated cooling water lines and discharge from equipment. Caution should be exercised around Category 2 water. Materials exposed to Category 2 water may not be salvageable.
- Category 3: “Black water” is highly contaminated, dangerous water that carries a significant risk of disease, infection and irreparable damage. Sources of black water include sewers, drain backups and water that has overflowed from rivers, lakes or the sea. Extreme caution should be exercised around Category 3 water. Most materials exposed to Category 3 damage will likely need to be replaced.
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Prevention Is the Best Strategy
As the saying goes, “the best offense is a good defense.” Addressing small issues before they cause major damage, creating a response plan and training maintenance teams on water damage response can all help property owners minimize damage, disruption and expense from a water event.
Training for Maintenance Teams
A building’s maintenance teams should receive training and instruction on how to address water issues to minimize damage. Training should include the location and proper use of all water shutoff valves, as well as information about water leak detection and suppression technology in the building. One very important instruction for maintenance teams is to avoid the bad plumbing habit of using caustic chemicals to clear drains. These chemicals quickly eat through clogs, but they can also eat through plumbing, causing bigger issues in the future. They can also push clogs further into the plumbing system, making them harder to properly clear.
Regular Building Inspections
Maintenance staff should establish a weekly inspection routine throughout the building to identify potential problems early. Any plumbing issues identified should be remedied, rather than being placed on deferred maintenance lists. Deferred maintenance represents one of the biggest causes of loss events for commercial buildings. While these tasks may require some time and investment on the front end, they can potentially save millions when considering the cost of water damage and mold remediation.
Regular building inspection routines should identify:
- Any roof drains or gutters that are obstructed or not draining correctly
- Ice damming that may occur on roofs in wintertime
- Downspouts that are not properly directing water away from the building
- Low spots, puddles, cracks or missing shingles on the roof
- Improperly sealed exterior penetrations of the building envelope (e.g.: seals around windows, doors, AC unit vents, etc.)
- Exterior grading that does not direct water away from the building’s foundation
- Low spots or puddles on sidewalks or parking lots
- Storm drains and catch basins that are blocked or not draining correctly
Reduce Water Demand in the Building
One way to help limit the stress on the water system in a building is to install high-efficiency appliances and fixtures. In a high-rise building, replacing appliances in each unit with high-efficiency models can make a significant difference in the volume of water demand. Less water flowing through the building means less stress on the plumbing and less water that may find its way into places it shouldn’t be.
Inform Tenants of Their Responsibilities
Tenants — whether they are businesses in a commercial space or residents in a high-rise apartment building — must be made aware of their responsibilities for water management. In most cases, this amounts to their notifying maintenance in a timely manner when issues arise. These issues can range from slow-draining showers to gurgling toilets. Building management should also provide information about what can and cannot be put down the drains in the building.

Implementing Floodproofing Strategies
In contrast to water leaks and pipe bursts that may occur in a building, flooding occurs when water outside of the building rises, covering dry land and flowing into the building. Floodwater can cause significant issues for a commercial building, including health risks, property damage, and structural issues. There are a variety of strategies to help stop or limit water damage that may occur from flooding. Depending on the size and type of building, some or all of the following strategies should be implemented.
Dry Floodproofing
The goal of dry floodproofing is to prevent water from entering the building in the first place. This is mainly accomplished by applying waterproof coatings to walls and floors. When the soil around a building becomes saturated, hydrostatic pressure will work to force water into interior spaces. Waterproof coatings on walls and floors can help keep this water out. Additionally, flooding that overwhelms storm sewers can cause sewage to back up through floor drains and into buildings. This can be avoided by installing backflow prevention valves on building drains. Other dry floodproofing strategies include installing flood shields on windows and doors.
Wet Floodproofing
Wet floodproofing strategies involve allowing water to enter and exit interior spaces. These strategies are not suitable for living spaces but are ideal for underground parking areas and storage areas. Examples of wet floodproofing strategies include installing floor drains to allow water to exit the space quickly and efficiently before causing damage.
Integrated Floodproofing
Integrated floodproofing combines wet and dry floodproofing strategies. Examples of integrated floodproofing include the building of waterproof enclosures for essential equipment, installing floor drains in main underground corridors and installing sump pump systems to clear areas of floodwater that may enter.

Call the Professionals
No matter how well-trained a building’s maintenance team is, it may not be equipped to respond to the kind of water damage that can occur from a leak or flood in a commercial or high-rise building. Floodwaters can bring in dangerous contaminants, and water leaks can lead to mold issues that jeopardize the health of maintenance crews, tenants and residents. The good news is that the trusted recovery partners at First Onsite are trained to respond to these events, and can help guide the recovery process from start to finish, even assisting with the insurance claims process. When disaster strikes, don’t go it alone — contact First Onsite.