Which is the Better Commercial Roof, Fully Adhered EPDM or Ballasted?

Hey Metro Detroit property managers and building owners, Bill Jr. here from Four Seasons Kanga Roof!

If you manage a commercial facility in the Tri-County area—whether it is a 5,000 sq. ft. retail space or a 100,000 sq. ft. manufacturing plant—you know that replacing a flat roof is a major capital investment. When exploring EPDM (rubber) roofing options, one of the most common questions we get during our consultations is:

“Which is better: a fully adhered EPDM system or a ballasted one?”

In the spirit of our They Ask, You Answer philosophy, I am going to give it to you straight. The honest answer is: It entirely depends on your building’s structural capacity, your budget, and your long-term desired outcomes. At Four Seasons Kanga Roof, We Do What it Takes to make sure you get the right system for your specific property. As an Elevate Master Contractor (a status we’ve achieved 3 out of the past 4 years, placing us in the top 1% of commercial roofers nationally), we have installed miles of both systems. We also work extensively with other industry leaders like Elevate, Mulehide, and Versico.

Let’s break down the facts, backed by the manufacturers themselves, so you can make an informed decision with zero guesswork.

The Heavyweight: Ballasted EPDM Systems

In a ballasted system, the insulation and the EPDM membrane are loose-laid over the roof deck. Instead of using screws or glue to hold the rubber down, the entire system is held in place by weight—typically river-washed stones or concrete pavers, applied at a minimum of 10 pounds per square foot.

The Pros:

• Fast and Economical Installation: Because we don’t have to wait for adhesives to cure or individually mechanically fasten every square foot, installation is incredibly fast. According to Elevate, this reduces labor costs and allows installations to happen in almost any weather condition.
• Excellent UV Protection: The layer of stone blocks the sun’s UV rays from hitting the rubber membrane directly, which can significantly extend the weathering life of the EPDM.
• Sustainability: When it’s time for a replacement, the un-adhered membrane and insulation are very easy to remove, reuse, or recycle.

The Cons:

• It is Incredibly Heavy: Your building’s structural deck must be engineered to hold a massive amount of dead weight. Older buildings or standard lightweight decks simply cannot support a ballasted roof.
• Leak Detection is a Nightmare: If a leak occurs, water can travel under the loose-laid membrane. Finding the exact puncture requires moving tons of heavy, dirty rock to inspect the rubber, which drives up maintenance costs.
• Broken Rocks Lead To Leaks: Over time the quality of the stone used for ballasted roofs has lessened. This has lead to higher instances of rocks shattering or breaking and when HVAC or maintenance workers walk on the roof, it can lead to tears in the membrane and difficult leaks to find. 

Bill Jr.’s Take: Ballasted systems are fantastic if you have a massive, flat roof that can handle the structural load and you want a cost-effective, fast installation. However, they require proactive exterior maintenance programs to ensure debris isn’t clogging drains under the rocks.

The Premium Standard: Fully Adhered EPDM Systems

In a fully adhered system, the EPDM membrane is completely glued down to the insulation board, which is mechanically fastened to your roof deck.

The Pros:

• Unmatched Wind Uplift Resistance: Because the adhesive evenly distributes the uplift pressure across the entire roof, fully adhered roofs boast incredible wind ratings. As Carlisle SynTec points out, this method prevents the membrane from fluttering in high winds, providing the best long-term performance.
• Lightweight Flexibility: Without the need for tons of rock, this system is lightweight and can be installed on almost any building, including roofs with slopes or complex shapes.
• Easy to Maintain and Repair: Because the membrane is fully bonded, water cannot travel far if a puncture occurs. The entire roof is visible, making inspections and emergency repairs fast and straightforward.

The Cons:

• Possible Higher Initial Cost: Fully adhered systems are more labor-intensive. Applying the bonding adhesive perfectly requires highly trained crews and favorable weather conditions, making the upfront investment higher.

Bill Jr.’s Take: For the vast majority of our commercial clients in Macomb, Oakland, and Wayne counties, fully adhered is the superior long-term choice. It provides peace of mind, a clean aesthetic, and the highest degree of stability.

The Bottom Line: Straightforward Pricing & Remarkable Service

Whether you choose ballasted for its economy or fully adhered for its unbeatable wind resistance, the most important factor is the team installing it.

We don’t practice on your property. Every member of our commercial roofing team trains in our in-house simulator before they ever step foot on your roof. We run our business on the EOS (Entrepreneurial Operating System) so that our operations are tight, our core value of We Care shines through, and we always deliver on our Apples to Apples Guarantee. We provide a straightforward pricing guide for repairs and maintenance, so you know exactly what you are paying for—no surprises.

If you are a facility manager or building owner looking for an honest assessment of your commercial roof, head over to www.kanga-roof.com to schedule a consultation. We’ll help you figure out the exact ROI for your building.

As always, I hope this article helped explain the differences and right applications for a ballasted versus full adhered EPDM roof for your commercial building. And most of all, I hope you have a Kanga-Rific Day!

Sincerely,

Bill Burkhardt, Jr.

VP & Owner