The Importance of Ballast Stone Removal in Commercial Roofing Projects

When it comes to commercial flat roofing systems, ballast stone has been a long-standing solution for securing roofing membranes — particularly in Built-Up Roofing (BUR) and ballasted EPDM systems. While effective in the past, many property owners and roofing professionals are now opting to remove ballast stone for several practical, structural, and environmental reasons.

In this blog, we’ll explore what ballast stone is, why it’s used, and the key benefits and process of ballast stone removal.

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What Is Ballast Stone?

Ballast stone refers to loose gravel or stone, typically ranging from 1 to 2.5 inches in size, that is spread evenly over a flat or low-slope roofing membrane. Its primary purposes include:

    •    Weighing down the roofing membrane to prevent wind uplift.

    •    Protecting the membrane from UV radiation and physical damage.

    •    Providing fire resistance by acting as a heat shield.

Although this system has worked for decades, many building owners are discovering that ballast stone can lead to long-term challenges that outweigh its initial benefits.

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Why Remove Ballast Stone?

1. Structural Load Concerns

Ballast stone adds significant weight to a roof — often up to 10–12 pounds per square foot. Over time, this extra load can compromise the structural integrity of the building, especially in older buildings not designed to handle that burden.

2. Drainage Issues

Loose stone can block drains and cause water to pool, increasing the risk of leaks and water damage to the roofing system and the interior of the building.

3. Membrane Inspection & Repair

It’s difficult to detect problems under a layer of ballast stone. Removing it allows for easier inspection, repair, and maintenance of the membrane, increasing the roof’s life span.

4. Transition to More Efficient Systems

Many commercial property owners are switching to more modern, energy-efficient systems like TPO, PVC, or modified bitumen, which often require the removal of ballast to allow for a fully adhered or mechanically fastened installation.

5. Environmental Considerations

Ballast stone can absorb and retain heat, contributing to the urban heat island effect. Reflective membrane systems offer better energy efficiency and help reduce cooling costs.

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The Ballast Stone Removal Process

Ballast removal is a labor-intensive task that requires specialized equipment and safety measures. Here’s how a professional crew typically handles the process:

    1.    Preparation & Safety

Set up fall protection, mark off work zones, and plan for debris containment.

    2.    Stone Vacuuming or Shoveling

Industrial vacuums or skid-steers are used to collect and remove the stone efficiently.

    3.    Hauling & Disposal

The ballast is transported offsite or repurposed if clean and uncontaminated.

    4.    Roof Surface Preparation

After removal, the membrane is cleaned and inspected. If a re-roof is planned, the surface is prepped accordingly.

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Choosing the Right Contractor

Ballast stone removal is not a DIY project — it requires knowledge of roofing systems, structural loads, and OSHA-compliant practices. Be sure to hire a licensed and insured roofing contractor with experience in commercial roof demolition and replacement.

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Final Thoughts

While ballast stone served its purpose for many years, times have changed. With new roofing technologies offering better performance, energy efficiency, and sustainability, ballast stone removal is often the first step toward a better roof — and a better building.

If you’re considering re-roofing your commercial property or want a professional evaluation of your existing ballasted system, reach out to a trusted roofing expert today.