Commercial Roofing Expansion Joint Repair: What Building Owners Should Know

Commercial Roofing Expansion Joint Repair: What Every Gainesville Property Owner Should Know

Expansion joints are one of the most overlooked—and most critical—components of any commercial roofing system. They quietly absorb structural movement, thermal changes, and even seismic activity. But when they fail, the consequences aren't quiet at all.

If you own or manage a commercial building in Gainesville or surrounding areas like Cumming, Buford, or Dahlonega, here's what you need to know to keep your roof watertight and structurally sound.

What Are Expansion Joints?

In short, expansion joints are flexible, watertight connections that allow sections of your roof—and the building beneath it—to move independently without tearing the membrane or damaging the system.

This movement can be caused by:

• Thermal expansion and contraction (especially in Georgia’s hot summers and cold winters)

• Structural shifts from settling or wind loads

• Changes in building use or occupancy loads

• Seismic activity

Without properly installed and maintained joints, the roof membrane can split, buckle, or leak.

Common Signs of Expansion Joint Failure

You might not see it from the ground, but some symptoms of failure include:

• Cracked or detached joint covers

• Buckling or ridging along the joint

• Water intrusion or pooling near curbs

• Tearing of adjacent membranes

• Loose or missing fasteners on metal caps

Ignoring these issues risks expensive interior damage and potential liability.

How We Approach Expansion Joint Repair at L&L Roofing

At L&L Roofing & Construction, we follow National Roofing Contractors Association (NRCA) guidelines to ensure reliable performance and long-term value.

Here’s our proven process:

1. Inspection & Diagnosis

We examine the entire expansion joint path, including curbs, parapets, and membrane tie-ins. We look for differential movement between roof sections and signs of previous improper repairs.

2. Material Selection

We choose repair systems based on the roof type and building conditions. Common options include:

• Premanufactured bellows covers for high-movement areas

• Brake-formed metal caps sealed with flexible flashing for curb areas

• Membrane-compatible flashings to ensure waterproof transitions

All materials meet ASTM and NRCA standards for elongation and weather resistance.

3. Proper Elevation

Raised curb-type expansion joints—at least 8 inches above the roof membrane—are used in most Georgia applications to prevent water damming and ice buildup.

4. Waterproofing & Flashing

We use sealants and backer rods designed for thermal and structural movement, ensuring a tight seal that lasts.

Why Expansion Joint Repair Matters

When properly designed and maintained, expansion joints:

• Prevent leaks and moisture intrusion

• Reduce stress on the roofing system

• Prolong the life of your investment

• Help ensure code compliance and insurance eligibility

Failure to maintain expansion joints is one of the most common causes of early commercial roof failure.

L&L Roofing: Doing the Right Thing for Your Building

Luke Heaps and the team at L&L Roofing & Construction take pride in doing things the right way—every time. We don’t believe in quick patch jobs or temporary fixes. We believe in building trust, protecting your property, and delivering quality that lasts.

We serve commercial properties throughout Gainesville, Cumming, Buford, Dawsonville, and beyond. If you suspect your roof's expansion joints are failing—or if it’s just time for a maintenance check—give us a call.

📞 (770) 874-0372
🔗 Visit our website

FAQ: Expansion Joint Repair for Commercial Roofs

How often should expansion joints be inspected?
At least annually, and after any major weather event. Movement and water intrusion aren’t always visible without a rooftop inspection.

Can you repair expansion joints without replacing the whole roof?
Yes. In many cases, targeted joint repairs can restore integrity without full replacement, especially when caught early.

Are all expansion joints visible from the surface?
No. Some may be concealed below membranes or inside parapet walls, requiring expert evaluation.

What’s the most common cause of joint failure?
Age-related material degradation and improper installation are the top culprits. UV exposure and thermal cycling take a toll over time.