Parapet Wall Flashing for Single Ply Roofing: What Gainesville Homeowners Need to Know

Single ply roofing systems—like TPO, EPDM, and PVC—are a popular choice for both low-slope residential and commercial roofs around Gainesville. But if your home or building has a parapet wall, proper flashing isn't just a detail—it's essential.

Let’s break down what parapet wall flashing is, why it matters, and how L&L Roofing & Construction makes sure it’s done right.

What Is a Parapet Wall?

A parapet wall is a short wall that extends above the roofline, often along the edge of a flat or low-slope roof. You’ll find them on many modern homes, townhouses, and commercial buildings.

These walls look great and provide protection—but they also create a prime spot for roof leaks if not properly flashed.

Why Parapet Flashing Matters for Single Ply Roofs

Single ply membranes are designed to be watertight across flat surfaces. But when the membrane has to bend vertically up a parapet wall, things get more complicated. That’s where flashing comes in.

Proper parapet flashing helps:

• Prevent water intrusion at the base of the wall

• Bridge horizontal and vertical surfaces cleanly

• Allow thermal movement of the roofing membrane without causing stress or tears

• Meet manufacturer warranty requirements

If flashing is done wrong—or skipped entirely—expect water to sneak in behind your membrane, often unnoticed until it causes major damage inside the building.

Our Step-by-Step Flashing Process

At L&L Roofing, we install parapet flashing on single-ply roofs with precision and integrity. Here's how we typically do it:

1. Membrane Termination at Wall Base
   The membrane is fully adhered or mechanically attached, then taken up the wall at least 8"–12", per code and best practice.

2. Reinforced Corner Detailing
   Inside and outside corners are reinforced using manufacturer-approved T-joint patches or corner boots.

3. Termination Bar or Counterflashing
   We install a metal termination bar near the top of the membrane where it meets the wall. This gets sealed with a high-grade urethane or silicone sealant and sometimes covered with a metal counterflashing.

4. Cap Metal Installation
   For parapets with cap metal, we carefully fasten and seal the top, with cleats and expansion joints as needed to allow for thermal movement.

5. Tie-Ins to Roof Edge Flashing
   At corners and edges, we integrate with drip edges, gutters, and coping caps to ensure a watertight perimeter.

This isn’t guesswork. Our team follows manufacturer specs from leading brands like GAF, Johns Manville, and Versico to keep your roof under warranty.

Parapet Flashing Red Flags to Watch For

Not sure if your current flashing was installed properly? Here are common issues we see during inspections in Gainesville, Buford, and Dawsonville:

• Bubbling or detachment of membrane at the wall

• Water stains below parapet intersections

• Exposed or missing termination bar

• Gaps in metal counterflashing

• Membrane not extended high enough on the wall

If you see any of these signs, it’s time to call us for a roof inspection.

We Do It Right the First Time

At L&L Roofing & Construction, we don't cut corners—literally or figuratively. Whether we're replacing a flat roof in Cumming or installing a new TPO system in Flowery Branch, we make sure every detail, like parapet flashing, is done with honesty, precision, and care.

Why? Because that’s what protects your investment for decades—not just a few years.

FAQs

How tall should the single-ply membrane go up the parapet wall?

Most manufacturers require at least 8"–12" above the finished roof surface. Some may require more depending on climate and code.

What kind of sealant is used for termination bars?

We use high-grade urethane or silicone-based sealants compatible with your specific membrane.

Can I install coping metal over a single-ply membrane?

Yes, and it’s common. We use cleats and expansion joints to allow the cap metal to move independently without tearing the membrane.

Does this apply to residential flat roofs too?

Absolutely. Any roof with a parapet—residential or commercial—needs proper flashing at the base and top of the wall.

Need parapet flashing inspected or installed? Call L&L Roofing at (770) 874-0372 for expert single ply roofing in Gainesville and surrounding areas.