Flat roofs have long been misunderstood in the world of commercial construction. From the outdated idea that “flat roofs always leak” to the belief that “metal roofs last forever,” there’s no shortage of misinformation floating around. At Etheridge Roofing, we specialize in commercial flat roofing—and we’re here to set the record straight.

 

Whether you’re a property manager overseeing multiple buildings or a business owner focused on long-term value, understanding the truth behind these myths can save you money, time, and a whole lot of headaches.

 

Let’s dive into some of the most common myths and the facts that debunk them.

 

Myth #1: Flat Roofs Always Leak

 

Fact: While it’s true that poor installation or lack of maintenance can cause any roof to fail, a professionally installed and maintained flat roof is just as watertight as any pitched system. At Etheridge Roofing, we use high-quality, single-ply membrane systems (like TPO or PVC) with expertly sealed seams, proper drainage, and edge metal details fabricated in-house at our ES-1 certified shop.

 

Many leaks originate from penetrations or improperly installed flashing—not the membrane itself. Regular inspections and scheduled maintenance help prevent these issues long before they result in water damage.

 

Myth #2: Metal Roofs Last Forever

Fact: Metal roofing is durable, but it’s not invincible. A commercial standing seam or ribbed metal roof can last 30–50 years when properly installed and maintained. However, over time, seams can weaken, fasteners can back out, and coatings can deteriorate.

 

If your metal roof is rusting, ponding water, or showing seam separation, it’s time for a professional evaluation. Many clients opt to restore their aging metal roofs with a membrane overlay system, which improves performance and often extends the life of the roof by 15–20 years.

 

Myth #3: Flat Roofs Don’t Have Any Slope

Fact: All flat roofs must have slope—typically a minimum of 1/4 inch per foot—to direct water toward drains or scuppers. In fact, improper slope is one of the leading causes of ponding water and premature failure.

 

At Etheridge Roofing, we assess the slope of every existing roof before beginning any re-roof or recovery. If needed, we can build in new tapered insulation systems to ensure proper drainage and warranty compliance.

 

Myth #4: Flat Roofs Are Inefficient in Extreme Temperatures

Fact: Today’s commercial flat roofing systems are designed with energy efficiency in mind. White reflective TPO membranes, for example, meet or exceed ENERGY STAR® standards and can significantly reduce cooling costs in warm climates.

 

We often pair these systems with high-R-value polyiso insulation to improve thermal performance year-round. That means better energy control, lower utility bills, and a smaller carbon footprint.

 

Myth #5: Flat Roofs Are Cheaper—But Only Because They’re Lower Quality

Fact: Flat roofs are often more cost-effective upfront, but that doesn’t mean they’re “cheap.” Their cost is based on efficient use of space, fewer materials needed for complex framing, and easier access for maintenance.

 

High-quality commercial membranes, combined with expert installation and proper detailing, can provide decades of reliable performance. The key difference is in who installs it and how well the system is designed for your building.

 

Myth #6: Once My Warranty Expires, I Need a New Roof

Fact: A warranty expiration does not mean your roof is at the end of its life. Many commercial roofs remain fully functional well beyond their warranty period with proper maintenance and care.

 

That said, if your warranty is expiring, it’s a smart time to schedule a comprehensive inspection. We’ll identify any developing issues and recommend proactive repairs that can help extend the life of your roof—potentially saving you thousands in premature replacement costs.

 

Bonus Myth: All Flat Roofs Are the Same

 

Fact: There are several types of commercial flat roofs—including TPO, PVC, modified bitumen, and EPDM—each with different performance characteristics. The right system depends on your building’s use, climate, foot traffic, and long-term goals.

 

Etheridge Roofing doesn’t believe in one-size-fits-all solutions. We tailor every project to meet our client’s unique needs, with full transparency about the pros and cons of each option.

 

The Bottom Line: Myths Can Cost You

Believing roofing myths can lead to poor decisions, unnecessary repairs, and even full system failures. Our job at Etheridge Roofing is to help you make informed choices backed by facts, experience, and real-world data.

 

We bring decades of expertise, ES-1 certified metal fabrication, and Centurion-level installation standards to every job we take on. Your flat roof doesn’t have to be a liability—it can be an asset that protects your investment for decades.

 

Let’s Talk About Your Roof

Whether you’re due for a re-roof, facing an expiring warranty, or simply want clarity on your current system, Etheridge Roofing is here to help.Call us today at 888.707.6634 or Visit us at etheridgeroofing.com

 

Sources:

• National Roofing Contractors Association (NRCA)
• ENERGY STAR Roofing Guidelines
• Carlisle SynTec Systems Technical Bulletins
• GAF Commercial Roofing Resources
• Johns Manville Roofing Systems