Industrial Metal Roofing: Overhang Flashing Systems Explained

When it comes to industrial metal roofing, one of the most overlooked yet essential components is the overhang flashing system. Whether you’re managing a warehouse in Gainesville or a plant in Dawsonville, this detail could mean the difference between a watertight system and costly repairs.

What Is Overhang Flashing?

Overhang flashing is the metal trim installed at the edge of a roof—specifically at the eaves and rakes. Its job? Direct water away from your building and into the gutter system.

Why It Matters:

• Water Control: Prevents water from dripping behind gutters or soaking into fascia.

• Wind Uplift Resistance: Reinforces panel edges against high winds.

• Aesthetic Finish: Offers a clean, finished look to the roof perimeter.

• System Longevity: Helps protect fasteners and underlayment at the most vulnerable points.

Key Components of a Flashing System

• Eave Trim: Directs water into gutters.

• Drip Edge: Protects the deck edge and fascia by kicking water out and away.

• Closure Strips: Seal off gaps between panels and trim to prevent wind-driven rain.

• Rake Trim: Installed along gable edges to block lateral water entry.

Best Practices for Installation

At L&L Roofing & Construction, we follow the Metal Construction Association guidelines and International Building Code standards for all flashing installs. Here's how we do it right:

• Use G90 galvanized or Kynar-coated steel to withstand corrosion.

• Flashing is installed over underlayment but under panels—unless it’s the final trim.

• All joints are sealed with butyl tape or high-grade sealants.

• Overlaps are minimum 4 inches with sealant and fasteners spaced 6” on center.

Real-World Example

We recently completed a standing seam roof on a processing facility in Cumming. Without proper rake trim, the previous roof had severe water staining on the interior walls. After replacing the edge flashings and adding foam closures, that leak has stayed sealed—rain or shine.

FAQs

How long does metal roof flashing last?
When properly installed, flashing can last as long as your roof—often 40-60 years.

Do I need flashing if I have gutters?
Yes. Gutters help control drainage, but flashing ensures water enters them properly.

Can flashing be added to an existing roof?
In some cases, yes. But it depends on your panel profile and condition. We can inspect and advise.

How much overhang is recommended for metal roofing?
Typically, 1” to 1.5” over the eaves. Too much can lead to wind damage; too little, and water may backtrack.

Need help evaluating your current roof or planning a new install?

Call L&L Roofing & Construction at (770) 874-0372. We serve Gainesville, Cumming, Dahlonega, Buford, and surrounding areas with honest advice and top-tier craftsmanship.