If you manage or own a commercial building in the St. Louis metro, the roofing system you choose affects your budget, your energy bills, and how many times you'll be dealing with repairs over the next two decades. The three most common systems for low-slope and industrial buildings in our region are TPO, EPDM, and metal — and each one fits a different kind of building, budget, and priority.

Here's how they compare, and how to figure out which one makes sense for your property

Quick Answer: Which Roofing System Is Best?

There's no single "best" commercial roofing system — the right choice depends on your building type, budget, and how long you plan to own the property. In general:

•    TPO is the most popular choice for buildings that need energy efficiency and a mid-range budget — think retail centers, restaurants, and warehouses.

•    EPDM is a strong option when budget is the top priority and the building isn't heavily impacted by summer heat gain.

•    Metal roofing costs more upfront but lasts the longest, making it the best long-term value for owners who plan to hold the property for decades.



TPO Roofing (Thermoplastic Polyolefin)

TPO is a single-ply membrane that's become the standard choice for commercial flat and low-slope roofs across the St. Louis area over the past decade. It's heat-welded at the seams, reflects sunlight to reduce cooling costs, and holds up well against St. Louis's swing between humid summers and freezing winters.

Pros:

•    Highly reflective (white or light-colored), which lowers summer cooling costs

•    Resistant to UV, chemical exposure, and punctures

•    Heat-welded seams are stronger than adhered or taped seams when installed correctly

•    Lighter weight than some alternatives, which can simplify structural requirements

Cons:

•    Performance varies significantly by manufacturer and membrane thickness

•    Seam quality is only as good as the installation crew — this is where most TPO failures start

Best for: Warehouses, distribution centers, retail buildings, and restaurants — especially owners looking to cut energy costs on a building with a lot of roof surface exposed to direct sun.

EPDM Roofing (Rubber Membrane)

EPDM — often just called "rubber roofing" — has been used on commercial buildings for more than 50 years and remains one of the most budget-friendly, proven options for low-slope roofs. It's especially common on buildings where the roof is ballasted (held down with stone or pavers) rather than fully adhered.

Pros:

•    Lower material and installation cost than TPO or metal

•    Long track record of durability in a range of climates

•    Flexible in cold temperatures, which matters for our Midwest winters

•    Easier and generally cheaper to repair than more complex systems

Cons:

•    Traditionally black, which absorbs heat and can increase summer cooling costs (white EPDM is available at a higher cost)

•    Seams are adhered or taped rather than heat-welded, so they need regular inspection

Best for: Buildings where upfront cost is the deciding factor, ballasted roof systems, and owners who prioritize proven reliability over energy performance.

Metal Roofing

Metal roofing systems — standing seam panels are the most common commercial application — are the long-haul option. They cost more to install but can outlast TPO and EPDM by decades, which changes the math for owners who plan to hold onto a property long-term.

Pros:

•    Longest lifespan of the three systems, often 40+ years with proper maintenance

•    Excellent performance against wind, hail, and heavy snow loads

•    Low maintenance once installed correctly

•    Strong resale and insurance value due to durability

Cons:

•    Highest upfront material and labor cost

•    Repairs, when needed, can require specialized crews

•    Not always ideal for very low-slope roofs without the right panel system

Best for: Industrial buildings, manufacturing facilities, and any owner planning to hold the property for 20+ years who wants to minimize lifecycle roofing costs.

What Actually Determines the Right System for Your Building

Cost and lifespan matter, but the right system for your building depends on a few other factors we walk through during every inspection:

•    Roof slope and drainage — flat, low-slope, and steep-slope roofs each favor different systems

•    Existing structure and insulation — recover vs. full tear-off changes which systems make sense

•    How long you plan to own the building — a 10-year hold and a 30-year hold justify very different budgets

•    Energy costs — buildings with large roof surfaces and high summer cooling loads see the most benefit from reflective membranes

•    Local weather exposure — hail, wind uplift, and freeze-thaw cycles are all factors specific to the St. Louis and Metro East climate

Frequently Asked Questions

Which is cheaper, TPO or EPDM roofing?

EPDM is typically less expensive upfront than TPO, both in material and installation cost. However, TPO's energy savings from reflectivity can offset the price difference over time, especially on buildings with high cooling costs.

How long does a TPO roof last?

A properly installed and maintained TPO roof typically lasts 20 to 25 years, though membrane thickness and installation quality both affect actual lifespan.

Is metal roofing worth the extra cost for a commercial building?

For owners planning to hold a property long-term, metal roofing is often worth the higher upfront cost because it can last 40 years or more with minimal maintenance, reducing total lifecycle roofing costs compared to replacing a membrane roof two or three times over the same period.

Can I switch roofing systems when I replace my commercial roof?

In most cases, yes. Switching systems during a replacement is common, particularly when an owner wants better energy performance or a longer-lasting system. A roofing contractor will need to evaluate your existing structure and insulation to confirm compatibility.

What's the most common commercial roofing system in the St. Louis area?

TPO has become the most widely installed system on commercial and industrial buildings across the St. Louis metro over the last several years, largely due to its balance of cost, energy efficiency, and durability.

Not Sure Which System Fits Your Building?

Every roof is different, and the right system depends on your building's structure, budget, and how long you plan to own the property. Taylor Roofing has installed and maintained TPO, EPDM, and metal roofing systems across the St. Louis metro for over 100 years, and we're happy to walk your roof and give you a straight recommendation — no pressure, no upsell.

Call (618) 233-2424 or request a free inspection to get a professional opinion on the best roofing system for your property.