If you’re dealing with a leaking ballasted roof, you’re not alone. At Weather Shield Roofing Systems, we’ve been helping businesses solve roofing headaches for over 40 years, and ballasted roofs are one of the most challenging to repair. They may look sturdy with that layer of river rock or gravel, but when leaks show up, those stones quickly turn from protectors to problems. Let’s break down why these roofs leak, what makes repairs so tricky, and how to fix the issue for good.

What is a ballasted roofing system?

A ballasted roof is a flat or low-slope roof covered with a layer of smooth river rock or gravel. The stones hold down the roofing membrane and shield it from the sun’s UV rays. This system was designed to be durable and cost-effective when first installed. But the very rocks meant to protect your roof can make leak detection and repair a major challenge.

Why does a ballasted roof start leaking?

The membrane is hidden under thousands of pounds of stone

One of the biggest problems with a leaking ballasted roof is that the waterproofing membrane is buried under a thick layer of rock. Even a small puncture can go unnoticed until water seeps through the insulation, causing widespread damage. Finding the source of the leak often requires removing large sections of ballast, which is time-consuming and costly.

Rocks can cause their own damage

While rocks protect against UV rays, they also add 5–10 pounds per square foot of weight to your roof. Over the years, the stones can break down into sharp fragments that cut into the membrane—especially in areas where maintenance crews walk. Once water gets under the stones, it can become trapped, leading to mold, insulation deterioration, and structural issues.

Repairs and replacements cost more

Fixing or replacing a leaking ballasted roof isn’t as straightforward as other roofing systems. To make repairs, crews must first remove the rock ballast—often hundreds of thousands of pounds of it. The process of removal, disposal, membrane replacement, and re-ballasting is expensive, labor-intensive, and disruptive to your business operations.

Can a leaking ballasted roof be repaired without removing all the stones?

In some cases, yes—but it’s complicated. Small repairs may be possible if the leak location is obvious or if moisture scanning equipment can pinpoint the problem area. However, because leaks can travel within the roofing system before showing up inside the building, partial repairs can be risky.

For many businesses, a better long-term option is to remove the ballast entirely and switch to a more modern roofing system, such as a fully adhered or mechanically fastened membrane. These systems make inspections, maintenance, and repairs much easier—and they remove the extra weight from your building’s structure.

What’s the best long-term solution for a leaking ballasted roof?

If your roof is nearing the end of its lifespan or has multiple leaks, it may be time for a full re-roofing project. Many property managers choose to:

1. Remove the ballast – All rocks are vacuumed or shoveled off the roof and disposed of properly.

2. Inspect the deck – Check for and repair any water damage or structural issues caused by leaks.

3. Install a new membrane – Choose a high-quality, energy-efficient system that’s easier to inspect and maintain.

4. Set up a maintenance plan – Weather Shield’s Max Life ™ Roof Care program ensures your roof stays in top condition, helping prevent future leaks.

How can you prevent a ballasted roof from leaking again?

• Schedule annual roof inspections—yes, even for ballasted roofs.

• Minimize unnecessary foot traffic on the roof.

• Clear debris from drains so water doesn’t pool under the rocks.

• Address minor issues quickly before they become widespread damage.

Even though ballasted roofs were once considered a practical solution, the reality is that they can become costly to maintain over time. Proactive inspections and timely upgrades can protect your building and save you from expensive emergency repairs.

At Weather Shield Roofing Systems, we believe in transparent, cost-efficient solutions that keep your commercial roof performing at its best. If you’re dealing with a leaking ballasted roof—or want to avoid one—our team can help you evaluate your options and find the best path forward. Contact us today to schedule a consultation.

James Boelkins

Account Executive

James Boelkins is an account executive at Weather Shield Roofing Systems with a background in project management, client communication, and commercial roofing expertise. A 2019 Calvin University graduate, he began as a summer intern in 2017 and quickly rose through the ranks, gaining hands-on experience in project planning and site management. He stepped into his current role in December 2022.