Commercial roof leaks are common, but they’re often much more complicated than they first appear, especially in the case of multi-tenant or multi-residential unit buildings. First of all, a leak can appear in one unit, but actually begin in another. However, a very common problem is that leaks are often caused by other issues such as HVAC, plumbing, building envelope, exit doors, and windows. This adds another layer of complexity for roofers who must act like investigators to determine the true source.
This is why it’s so important to hire experienced roofers in the Greater Toronto Area. Not only can they identify and diagnose the true source of the leak, but they can also make the proper repairs and/or recommendations before the problem gets larger and more costly.
Because water naturally travels across corrugated decking, insulation, walls, or structural components before becoming visible, professional commercial roof leak detection is critical. Let’s take a look at why commercial roof leaks are so difficult to diagnose, and why clear communication with your roofer is vital in getting to the heart of the matter.
Why Are Commercial Roof Leaks So Difficult to Diagnose?
There are many reasons why commercial roof leaks pose such challenges when it comes to accurate diagnosis.
1. Water doesn’t always appear directly below the leak.
That’s because:
- Water can travel long distances before dripping inside a unit.
- Corrugated metal decking is an easy conduit for water to move from one tenant space to another.
- A leak that starts in one unit may show up 30 feet away in another area.
- Parapet wall leaks can mislead technicians if roof alignment is unclear.
Often, a tenant will report a leak in one location, but after inspection, the actual roof issue is found to be elsewhere.
2. Evidence of a leak often disappears before a roofer can inspect the situation
Not all leaks are active 24/7. Because many leaks can be weather dependent, evidence may be intermittent. In addition, tenants or maintenance staff often feel compelled to clean up puddles before roofers arrive. But without active dripping or visible evidence, diagnosis becomes much more difficult. It’s best for building occupants to leave the evidence alone, then call a roofer immediately during an active leak for prompt inspection.
If that’s not possible, photos and reports of exact locations greatly improve the accuracy of commercial roof leak detection.
3. Human memory is often unreliable
It’s human nature for memories to fade or people to make mistakes in recollection. As a result, tenants may forget the location or provide vague descriptions to roofers, which complicates matters. “It leaked over here last year” may not help if the current issue is originating elsewhere. And if there hasn’t been any rain in the forecast for days or weeks, what may present as a leak may not be one after all.
Because leaks are frequently reported without clear markings or documentation, roofers have a tough time identifying the source. Instead of relying on memory, it’s helpful for tenants to:
- Mark floors, or walls near the leak
- Take photos or videos during active dripping
- Note current weather conditions and timing
4. Roof conditions often hide the real problem
From standing water to wet insulation, there are many hidden issues that could be disguising the actual culprit.
- Standing water conceals punctures or seam failures.
- Winter conditions such as snow and/or ice may require snow removal before inspection can begin, while repeated freeze-thaw cycles can temporarily open and close leak pathways.
- Wet insulation traps moisture that can cause leaks long after the rain stops.
The type of roof system also plays a major role in how leaks are detected. For instance, conventional roof systems are generally easier to inspect due to the exposed membrane. In contrast, loose laid single ply membranes can allow water to travel to a roof penetration before showing up in the interior.
Roofers typically start near penetrations, such as parapet walls, skylights, drains, HVAC units, and tall cones/ exhaust vents. This is where roof leaks are most common and thus more easily detectable.
5. Lack of Timely Reporting
Commercial roof leak detection is not only complex, but it can often be deceptive. That’s why early and quick reporting during active leaks is encouraged in order to enhance diagnostic accuracy. Tenants and landlords can achieve this through detailed observations, photos, and exact locations.
When roofers have accurate and timely information, they are better able to make the necessary repairs to prevent bigger future problems and ensure warranty compliance.
A Look at the Commercial Roof Leak Detection Process
Here at Elite Roofing, we follow a fairly standard method of commercial roof leak detection. The better the communication between our team and the tenant or landlord, the higher the chance of success in finding the root cause quickly.
Step 1: Interview Occupants and Facility Managers
We start off by gathering information on the leak’s history and timing. Ideally we are meeting on-site with the person who knows exactly where the leak occurred. This is common but does not always work out that way in practice. This is where documentation on the part of the tenant comes in very handy. This will help us identify patterns during storms, snow melt, or temperature swings so we can verify exact leak locations.
Step 2: Interior Investigation
We start inside, inspecting ceiling tiles, walls, decking, and structural elements. Not all roofing inspections are complex. Sometimes our technicians use simple methods like poking visible spots from below while coordinating with roof crews above.
Step 3: Exterior Roof Inspection
Next, we move outside and inspect penetrations, seams, drains, flashing, and rooftop equipment. We’re on the lookout for punctures, open seams, loose flashing, or membrane damage that could be to blame.
Step 4: Advanced Diagnostic Testing
In some cases, we can use infrared roof scans to detect compromised areas of trapped moisture. This method is useful for large facilities or buildings with multiple suspected leaks. However, this step also requires verification with probing. If necessary, we can also cut out sections of roofing to find the source of hidden moisture.
We may also perform flood testing to determine if a leak is truly roof-related. This helps us rule out potential culprits like HVAC equipment, plumbing issues, or drain failures.
When the Roof Isn’t the Problem
Roofs aren’t always the source of a leak that shows up on the inside of a multi-tenant building. In fact, Howard Glowinsky of Elite Roofing estimates that 30% to 40% of suspected roof leaks are not actually caused by the roof membrane itself but rather due to:
- HVAC equipment left unsecured after maintenance
- Missing fasteners or open access panel covers
- Window or wall leaks
- Garage door openings
- Plumbing or drain issues including backups
- Condensation and humidity buildup
Myths vs. Facts About Commercial Roof Leak Detection
Myth #1: The Leak is Directly Above the Water Stain
Fact: Water often travels through decking, insulation, or walls before becoming visible, so the source may be away from the water-stained tile or pool on the floor of the warehouse.
Myth #2: If the Leak Stops, the Problem is fixed
Fact: Commercial roof leaks often depend on the weather and may only manifest under certain conditions.
Myth #3: Every Leak Translates to a Roof Problem
Fact: Not so. Leaks can also originate from HVAC equipment, plumbing, windows, drains, or condensation and humidity issues.
Myth #4: Roof Leak Detection is Straightforward
Fact: Commercial roof leak detection often requires specialized inspections, testing, and moisture tracing by experienced roofers.
Myth #5: Cleaning Up the Leak Before Calling a Roofer is Helpful
Fact: Photos, marked ceiling tiles, and reporting active leaks can help roofers diagnose problems faster. It is not helpful to clean up puddles and then call a roofer, as this removes the evidence needed to make an accurate diagnosis.
Myth #6: Small Leaks Aren’t Serious
Fact: Even small leaks can cause hidden insulation damage, mould, and structural issues over time, leading to worsening conditions if ignored.
The Elite Advantage
At Elite Roofing, we specialize in accurate commercial roof leak detection for complex roofing systems and multi-unit buildings in the Greater Toronto Area. Because we understand how water travels through commercial structures and use proven diagnostic methods to identify the true source of leaks, we help property managers avoid costly repeat repairs and long-term damage. That’s the Elite Advantage!
Contact Elite Roofing For Commercial Roof Leak Detection
If your multi-tenant building is experiencing recurring or unexplained leaks, contact Elite Roofing for professional commercial roof leak detection services in the Greater Toronto Area.
