Whether it’s a freshly built sunroom attached to a home or a large commercial building, many structures across Maine feature flat or low-pitched roof decks. While traditional materials may be great at protecting pitched roofs from heavy rain, snow, summer sun, and wind-driven salt spray, they often struggle to perform as well on flat surfaces. This is why EPDM rubber has long been the most trusted solution for keeping low-slope roofs or sections dry, quiet, and energy-efficient.

The comprehensive guide below is your complete roadmap to everything EPDM. Whether you’re a homeowner, manage a commercial facility, or are simply curious about flat-roof technology, you’ll find practical, experience-tested answers here.

1. EPDM explained

EPDM stands for ethylene-propylene-diene monomer – a mouthful that simply means synthetic rubber. When used for roofing, the material arrives on-site as a single-ply sheet that looks and feels much like the inner tire of a heavy-duty bicycle, and is just as flexible yet robust. Once it’s bonded to insulation on your roof deck, this membrane stretches, flexes, and seals out water in a way that traditional asphalt shingles or standing-seam metal can’t match on a low pitch.

Here are some of its properties you’ll actually notice:

• Wide temperature range: EPDM stays strong and elastic through Maine’s coldest February mornings and hottest July afternoons.
• UV and ozone resistance: It can withstand constant exposure to harsh UV rays and ozone, factors that rapidly wear and damage many other similar materials.
• Watertight seams: Adjacent sheets are completely fused into one skin, so there are no pathways for water to infiltrate.
• Low noise: EPDM significantly dampens the sound of rain and hail, especially when installed with the right underlayment and insulation.

2. A quick history lesson

This material hasn’t always been the sleek, high-tech membrane that we know today. Actually, it took seven decades of problem-solving and adding strength, flexibility, or energy performance that earlier generations lacked. Let’s take a look at the timeline that explains how modern EPDM came to be:

• 1950s and the birth of synthetic rubber: Chemists at DuPont were looking for a durable rubber substitute for automotive parts and weather seals, and EPDM answered the call.
• 1960s, when EPDM was first used for roofing: Forward‑thinking contractors glued early membranes to free‑span warehouses that couldn’t handle any other, heavier roofs.
• 1970s and popularity spike: As the costs of asphalt skyrocketed due to the oil embargo, single-ply membranes became more and more popular, especially in the flat-roof market.
• 1980s, ’90s, and the improvements in technology: As EPDM gained recognition, new versions focused on enhancements. Better seam connection options arrived, thicker membrane gauges became available, and service lives began stretching past three decades.
• 2000s to now and the shift in focus: Finally, the industry shifted toward maximizing energy efficiency and sustainability. White EPDM membranes now allow for “cool roof” solutions, while recycling and take-back initiatives help keep materials out of landfills.

After more than half a century in service, EPDM is no newcomer, it’s a time-tested and proven solution for scenarios where other roofing options simply fall short.

3. Anatomy of an EPDM roofing system

So far, we’ve only mentioned the EPDM membrane, but to make a full roofing system, you need much more than that. These systems have multiple layers, where each one plays an important role in protecting structures from threats. Let’s take a look at every tier of an EPDM roofing system and explore what each one contributes:

1. Structural deck: The foundation for any roofing system. The deck is made from plywood, OSB, or steel, and supports all the layers above.
2. Vapor barrier (optional): A layer that prevents interior moisture from moving upward into the insulation and the membrane itself.
3. Flat or tapered insulation: Typically made from polyiso boards, these help conserve energy and can be sloped to improve drainage.
4. Cover board: A dense, protective layer placed over insulation to guard against foot traffic and improve membrane adhesion.
5. Adhesive or fasteners: Used to bond or secure the membrane to the layers below, depending on the installation method.
6. EPDM membrane: The waterproof sheet itself, meticulously installed and seam-sealed into a single surface.
7. Flashing and counterflashing: Flexible EPDM pieces that seal around skylights, plumbing vents, and other penetrations.
8. Termination bar with sealant: A mechanical lock installed at wall edges, sealed with a bead of protective sealant.

As you can see, while the rubber membrane is the star of the show, every component has a job to do in a well-planned system.

4. Your selection of EPDM options

Now that we’ve covered the anatomy of this system, it’s time to learn about all the options available for the most important parts. EPDM can be surprisingly customizable, so you can pair features with your priorities.

Membrane thickness

• 45‑mil: Entry‑level option. Usually used on mild‑climate jobs, and is rare in Maine.
• 60‑mil: Thicker, stronger version for homes and light commercial buildings.
• 90‑mil: Exceptional durability where hail, foot traffic, and long lifespans matter.

Reinforcement & backings

• Non‑reinforced: Standard variant, ultra‑flexible around tight corners.
• Scrim‑reinforced: The membrane has a polyester grid that makes it more resistant to tears in mechanically attached systems.
• Fleece‑backed: Acrylic felt adds impact resistance and cushions minor deck irregularities.

Color palette

• Black: Absorbs winter sun and helps melt snow faster. Classic choice.
• White: A “cool roof” option that reflects sunlight to lower summer cooling loads in conditioned spaces.

Attachment methods

• Ballasted: The membrane lies loose, held down by smooth river rock. Fast and economical on large warehouse decks.
• Mechanically attached: Laps are secured with screws and plates, after which the seams are covered by tape. It’s a good option for reroof overlays.
• Fully adhered: The entirety of the membrane is covered by adhesive and bonded to the layer underneath. Unlike other options, it’s fully wind-resistant and a go-to in Maine.

5. Why EPDM shines in Maine’s climate

We can all agree that Maine’s climate is demanding, with its horizontal sleet, severe freeze–thaw cycles, and salt-laden coastal winds. But EPDM consistently rises to the challenge. Here are some of its biggest advantages:

• Longevity you can count on: When properly installed, 60‑ or 90‑mil sheets routinely last beyond the 30-year mark. In fact, some membranes from the early 1980s still pass modern tensile-strength tests. When you weigh cost against lifespan, EPDM often comes out ahead.
• Unmatched flexibility: Rubber’s natural stretch allows EPDM roofs to handle everything from sub-zero January nights to scorching July afternoons without splitting seams or loosening fasteners.
• Supreme water resistance: With waterproof membranes connected at the seams with proper tape, you get a chemically welded, uniform surface with no entry points for water. Add tapered insulation to guide runoff, and ponding water becomes a non-issue.
• Protection against wind: When fully adhered, EPDM membranes hold strong even in powerful coastal winds. And because the material isn’t metallic, salty air can’t corrode it.
• All-year energy efficiency: Black EPDM sheets absorb heat. While this isn’t a benefit for everyone, it can help melt snow and reduce the risk of ice dams in winter. And for buildings with significant cooling loads, white EPDM reflects up to 80% of summer heat.
• Quiet indoors during rain: Rubber dampens impact noise. Because of this, rain and hail sounds are softened or nearly silent, depending on your insulation and underlayment setup.

6. Recognizing the potential downsides

Like with anything, no roofing choice is flawless. Though most of them don’t usually cause people to give up on this solution entirely,  EPDM has some disadvantages. When you’re well-informed about them, you can plan for them rather than be surprised down the road.

• Aesthetics: A black membrane can look very utilitarian, especially if it’s clearly visible from other windows. But there are solutions if this is too big of an issue, from white membranes to rooftop patios.
• Puncture risk: Sharp branch stubs or dropped tools can damage thinner sheets. Luckily, there are now 90-mil membranes that are much stronger in comparison, and there’s always an option of adding walkway pads where traffic is expected.
• Professional installation: If you want a truly waterproof solution for a flat roof, then you need to rely on the experts. DIY kits exist, but seams done without rollers and primers often fail early.

But even when these considerations are weighed against longevity, weather performance, and sustainability, EPDM rubber still wins the value equation for many Maine properties.

7. Overview of the installation process

For your new system to perform at its full potential, it needs to be installed correctly. It’s a process that requires planning, coordination, and close attention to detail, so it’s always best left to professionals. Our team follows a clear, proven sequence to ensure every phase runs smoothly. Here are the steps you can expect:

Initial site visit

After you reach out to us, we’ll typically contact you within one day to schedule a site visit. During this one-hour visit, an estimator will go over all essential aspects like measurements, photos, and product options, and carefully evaluate the site before delivering a clear proposal.

Pre-production

Once the details are gathered, we’ll need a signed contract, a final color selection, and a 20% deposit to schedule your project. After that, your estimator will create a complete product packet that includes all key information, site photos, and the final contract. Then, they hand this packet off to our production team.

Production step

At this stage, our production team carefully reviews all project details, places material orders based on your selections, and comes up with a job timeline that fits your schedule. Once everything is confirmed, we’ll book a start date and assign a project coordinator for your EPDM roofing installation.

Construction

A designated project manager starts the project with an initial walkthrough to make sure the site is safe and ready to begin work. From there, we move through the following steps:

• Preparing the surface: Unless it’s a specific case that involves a code-approved overlay, the crew first removes the existing roofing materials. They clear, inspect, and, if needed, repair or replace the roof deck, then install any required underlayers.
• Laying out the membrane: Once the surface is prepared, roofers unroll the EPDM membrane and let it relax in the sun to reduce any material tension. They then carefully bond each sheet to the surface using a strong, specialized adhesive while making sure to lay it smooth and flat without wrinkles or trapped air.
• Seam welding: At every seam where two sheets meet, the crew applies primer to activate the factory-applied or freshly placed seam tape to form a watertight seal. Once the surfaces are fully prepared, they carefully align and press the sheets together with a heavy roller to create a continuous membrane.
• Detail flashing: To protect vulnerable areas like skylights, vent pipes, and corners, the crew installs and seals flexible flashing components using compatible primers and sealants.
• Edge terminations: The crew installs termination bars and applies sealant at all roof edges to lock the membrane in place and protect it against wind and water.
• Cleanup: After the construction is complete, roofers will thoroughly clean the site and make sure your property looks as good as when they arrived.
• Final walkthrough: You and the project manager inspect the finished roof together to confirm that everything meets your expectations. Once you’re satisfied, we activate your workmanship warranty and officially close out the project.

8. Small maintenance habits to build

From the roofing surface itself to gutters, from skylights to siding, the average home’s or another building’s exterior already demands plenty of attention. Luckily, EPDM rubber doesn’t add much to the chore list. A handful of seasonal habits are enough to keep the membrane performing like new. Here’s what you should do:

• Seasonal checkups: In spring and fall, set aside time to inspect the surface, clear away winter debris or fallen leaves, check the seams for wear, look for punctures, and make sure drains are flowing freely.
• Post-severe storm checkups: After any extreme weather event, take a quick look for fallen branches, debris, or wind-blown patio furniture that might have damaged the membrane.
• Professional inspection: Once a year, or sooner if you notice signs of damage, have a qualified professional examine the surface for small cracks or other issues and patch them before they become serious.
• Optional recoat: An acrylic or silicone coating refreshes UV protection and can even transform a black roof into a white, reflective surface that contributes to energy savings.

9. Environmental benefits of this option

Protecting your home or facility is a priority, but for many Mainers, doing so without harming the environment matters just as much. Here’s why rubber roofing consistently earns high marks for sustainability:

• Low embodied energy: The production process for EPDM requires fewer raw materials and less energy than other, more complex systems. EPDM has a lower carbon footprint right from the manufacturing stage.
• Extended lifespan reduces material waste: Since these membranes often last 30 to 40 years with proper care, the waste created by EPDM tear-offs is dramatically reduced. Fewer re-roofs also mean much less resources will be used for manufacturing, shipping, and disposal over the life of the building. 
• Recyclable at end of life: Old EPDM can be recycled into useful products like walkway pads, roof accessories, or ground cover. Responsible companies like ours make sure to collect all tear-offs and deliver them to our recycling partners whenever possible.
• Cool-roof options help cut energy use: Heat gain is a concern for buildings with high summer cooling loads, but white membrane options reflect sunlight and significantly reduce that gain. With lower demand on HVAC systems, utility bills decrease, and so does the strain on the electrical grid during peak months.
• Minimal jobsite waste: Because EPDM arrives in large sheets and uses precise seam tapes and adhesives, very little material ends up wasted on the ground. With our team, you can count on crews trained to maximize membrane coverage, recycle scrap wherever possible, and leave behind a spotless jobsite.

10. Myths we hear all the time, debunked

Rumors travel faster than facts, and roofing is no exception. Before misinformation steers you toward a material that might not suit your building, let’s set the record straight on five misconceptions we hear week after week.

Myth 1: Flat roofs always leak

Truth: It’s true that flat and low-slope roofs are more prone to water pooling, but that’s exactly what EPDM is designed to prevent. A properly installed rubber membrane over quality insulation is completely watertight and performs just as well as any pitched system.

Myth 2: Rubber roofs are noisy

Truth: Unlike many materials, EPDM is elastic and absorbs sound, especially when paired with the right insulation and underlayment. Most homeowners actually notice a quieter interior after switching to EPDM on low-slope areas.

Myth 3: It can’t handle Maine winters

Truth: Actually, his synthetic rubber remains flexible down to -40°F and even sheds snow faster than most materials. It’s built to endure harsh northern climates, Maine included.

Myth 4: EPDM makes the house hot

Truth: Traditional black membranes do absorb heat, but that can be a benefit, especially in unconditioned attics, where it helps melt ice dams. And for those worried about cooling in summer, white or white-coated EPDM is highly reflective and keeps interior temperatures down.

Myth 5: EPDM roofs have to look industrial

Truth: By itself, EPDM isn’t the most visually appealing option, but that doesn’t mean your roof has to stay that way. Edge metal in matching colors, architectural trim, paver patios, and deck railings can all turn a basic membrane into a visually appealing, functional outdoor space.

Need a low-slope roofing solution that lasts? Get in touch with Horch Roofing today

Low‑slope roofing is unforgiving, and even small mistakes during installation can become big leaks. After thousands of installations and 20+ years in business, Horch Roofing relies on EPDM rubber as one of our main options because it forgives, flexes, and performs on low-pitched and flat surfaces decade after decade. When paired with our manufacturer‑certified, OSHA-trained, and experienced crews and comprehensive warranties, it offers peace of mind you can count on.

Harsh winds, freeze–thaw swings, salt air in coastal areas, summer heat – our beloved state throws it all at a roof. That’s why we refine every detail specifically for our climate, from cold-weather adhesive protocols to tapered insulation that sheds water before it can pond and freeze. When you choose us, you’re choosing systems engineered to outperform in Maine’s uniquely demanding weather.

Need a steep-slope upgrade instead? We’ve got you covered there, too. Whether you’re interested in a classic asphalt shingle installation, looking to invest in a high-end standing seam metal roof, or planning to add seamless gutters to your system, we’re ready to help. With us, you get a single point of contact, consistent craftsmanship, and zero guesswork—no matter the pitch, material, or project size.

Ready to discuss a project in Warren, Portland, South Portland, or anywhere along the coast and beyond? Reach out for a free consultation and discover how a single sheet of modern rubber can protect your biggest investment for the next generation.