If you manage a commercial building in Eugene, chances are your roof is flat or close to it. Flat roofs are a popular choice for commercial properties thanks to their affordability, ease of installation, and functional design. But here’s the thing: when they go bad, they go really bad.
At NW Roofing and Siding Pros, we’ve seen every kind of commercial flat roof issue under the Oregon sun (and rainclouds). And if you’re reading this, chances are you’ve already spotted signs of trouble—maybe a mystery drip in your conference room, or a soft, spongy patch near your HVAC unit.
In this guide, we’ll walk through the most common commercial roofing trouble areas and flat roofing problems that businesses in Eugene face, and more importantly, how to solve them before they turn into costly disasters.
Ponding Water: The #1 Flat Roof Drainage Problem
Let’s start with the elephant-sized puddle on the roof.
Flat roofs aren’t perfectly flat. They’re designed with a slight slope to guide water to internal drains, scuppers, or gutters. But when those drainage systems fail or become blocked, water starts to pool.
Why It’s a Problem
Standing water, also known as “ponding,” accelerates membrane breakdown and increases the likelihood of leaks. It also adds weight your roof wasn’t designed to carry long-term, especially during our wetter seasons in Eugene.
What You Can Do
If you’ve noticed water lingering on your roof more than 48 hours after a storm, it’s time to act. We inspect for low spots and install tapered insulation systems or correct slope issues to restore proper drainage.
Membrane Damage & Blistering
TPO, EPDM, and PVC roofs are common choices for flat commercial roofs. These materials are tough, but they’re not invincible.
What Causes It?
UV exposure, poor installation, or water trapped under the membrane can lead to blistering, bubbling, or tearing. We often find these issues near HVAC units or in areas with poor drainage.
How We Fix It
Our team of certified commercial roofing contractors uses infrared and drone inspections to pinpoint moisture intrusion. From there, we patch or replace affected membrane sections with heat-welded seams that are built to last.
Flat Roof Leak Spots: Where They Happen Most
Roof Leaks are the most common complaint we get. And while a leak may appear in your ceiling, the source is usually more complex.
Common Leak Locations
- Around roof penetrations (vents, skylights, HVAC units)
- At flashing points where different materials meet
- Along seams or edges
- Near parapet walls or drainage scuppers
These aren’t just leaks. They’re warning signs that the roofing system is no longer watertight, and your building’s structure could be at risk.
How We Help
Our drone inspections are quick, safe, and incredibly precise. We find flat roof leak spots faster than traditional methods and fix them with durable materials that align with manufacturer warranties.
Clogged Drains & Poor Gutter Maintenance
This one might seem obvious, but it’s often overlooked.
Clogged drains and downspouts are a silent contributor to many commercial roofing trouble areas in Eugene. With our abundance of rain and falling leaves, it doesn’t take long for debris to build up and block the flow of water.
What Happens Next?
Once your drains are clogged, water backs up and starts seeping into seams, insulation, and even structural supports.
What We Recommend
Regular commercial roof maintenance, especially during fall and spring, is the best way to avoid flat roof drainage problems. We offer preventative maintenance packages that include routine checks, cleaning, and repairs before water damage sets in.
Flashing Failures at Critical Connection Points
Flashing is the metal or membrane material used to seal edges, joints, and penetrations. It’s essential to a watertight roofing system.
What Goes Wrong?
Flashing can pull away, crack, or degrade over time, especially if it wasn’t installed properly in the first place. This often happens around rooftop equipment or where the roof meets vertical walls.
What You Can Do
We replace failing flashing with commercial-grade materials and reinforce vulnerable joints to stop water in its tracks. Our technicians specialize in hybrid systems (membrane and metal or membrane and shingles), so no matter your setup, we’ve got you covered.
Roof Shrinkage & UV Damage
If your roof looks like it’s pulling away from the edges or you see wrinkling across the surface, you might be dealing with membrane shrinkage. This happens most often with older EPDM systems exposed to consistent sunlight without UV protection.
Why It’s a Big Deal
As the membrane shrinks, it stresses seams, flashing, and penetrations. Eventually, this leads to tears and leaks.
Our Solution
We reinforce stressed areas with compatible materials and recommend reflective roof coatings where appropriate (though we don’t install coatings ourselves). In many cases, replacement with a modern TPO or PVC system is the smarter long-term investment.
What Sets NW Roofing and Siding Pros Apart
We know there are a lot of roofing companies in Eugene promising quality work. So what makes us different?
We built this company in 2016 out of frustration with unreliable subcontractors, and we’ve been doing things better ever since.
✓ We’re a GAF Master Commercial Roofing Contractor
✓ Weatherbond and IKO Certified
✓ Experienced in complex hybrid systems
✓ Known for ethical practices, fast response times, and expert craftsmanship
And yes, we offer flexible financing through Hearth and up to 25 years of workmanship warranty, because doing the job right means standing behind it too.
Is Your Roof One Storm Away from Trouble?
If your roof has ponding water, bubbling membrane, or persistent leaks, don’t wait. The best time to fix a flat roofing problem is before it becomes a costly emergency.
We’re here to help. Whether you manage a small retail building or a sprawling warehouse, NW Roofing and Siding Pros is ready to inspect, diagnose, and repair your commercial flat roof issues so you can get back to business with confidence.
Call us today or email nwrspros@hotmail.com to schedule your estimate.
Let’s protect your investment before the next storm rolls in.