A guide explaining whether you should waterproof under a commercial epoxy floor coating. Learn how AZ Garage Floors helps businesses extend floor life—call (602) 254-3363 today for expert help.

Summary Highlights

  • Waterproofing prevents bubbling, peeling, and delamination caused by trapped moisture.
  • Vapor barriers and MVER testing ensure proper adhesion and floor longevity.
  • Polyaspartic and epoxy systems offer fast-curing, moisture-resistant protection.
  • Investing in waterproofing reduces repairs, downtime, and long-term costs.

When we install commercial epoxy and polyaspartic floor systems, one of the most common questions we hear is whether waterproofing is necessary under the coating. The short answer is—it depends on your environment and concrete conditions. At AZ Garage Floors, we’ve spent more than 30 years helping businesses prevent costly floor failures by understanding the science of moisture, adhesion, and protection.

Why Is Moisture a Concern Beneath Commercial Epoxy Floors?

Concrete may look solid, but it’s actually a porous material that constantly interacts with moisture. Water vapor naturally moves through the slab, and if that moisture becomes trapped beneath a non-breathable coating, such as epoxy, it can create hydrostatic pressure. Over time, this pressure can cause bubbling, peeling, or delamination, resulting in costly repairs. That’s why moisture vapor emission rate (MVER) testing is a critical first step before any commercial epoxy floor installation. It tells us how much vapor your concrete is emitting—and whether you’ll need a vapor barrier or waterproof primer to protect your floor coating system.

When Should a Waterproofing Layer Be Installed?

Waterproofing isn’t necessary for every commercial epoxy floor coating, but there are key situations where it’s absolutely recommended:

  • Below-grade slabs or basements, where moisture naturally collects.
  • Facilities exposed to water or humidity, such as commercial kitchens, labs, or food processing areas.
  • Outdoor-adjacent spaces like loading docks or garages, where rainwater can infiltrate.
  • High-traffic environments using heavy machinery or cleaning chemicals that could penetrate cracks.

In these cases, a waterproof underlayment or moisture barrier creates a protective seal between the concrete and the epoxy system, preventing water vapor from compromising adhesion or structural integrity.

How Does a Vapor Barrier Work with Epoxy or Polyaspartic Systems?

At AZ Garage Floors, we often recommend using a vapor barrier epoxy primer before applying the main commercial coating. This barrier serves as a moisture-blocking base coat, sealing concrete pores and reducing vapor transmission. Once cured, we use high-performance epoxy or polyaspartic topcoats designed for durability and chemical resistance. Polyaspartic coatings, in particular, provide excellent waterproofing because of their fast curing, UV stability, and low permeability. They’re ideal for extensive facilities that can’t afford extended downtime—our systems often cure within 24 to 48 hours, minimizing business disruption.

What Happens If You Skip Waterproofing Under Epoxy Floors?

Skipping waterproofing might save money up front, but it can lead to costly problems later. Without proper moisture control, you risk:

  • Delamination, where the epoxy loses adhesion and peels away.
  • Surface bubbling or blistering caused by trapped water vapor.
  • Staining and discoloration from moisture intrusion.
  • Reduced the lifespan of the entire coating system.

Over time, even small amounts of moisture can degrade the bond between the epoxy and concrete, compromising the floor’s strength and appearance. That’s why we continually assess moisture levels, surface prep needs, and humidity conditions before installing any system.

How Do We Ensure Long-Term Moisture Protection?

We follow a proven process designed for industrial and commercial environments that can’t afford downtime or recurring repairs. Every project includes:

  • Diamond grinding or shot blasting for proper surface profiling and adhesion.
  • MVER testing and humidity assessment to measure vapor pressure.
  • Installation of waterproof epoxy primers or vapor barriers when required.
  • QA testing for adhesion, slip resistance, and surface uniformity.

This detailed approach ensures the floor’s structural durability, safety compliance, and long-term value, whether it’s a warehouse, airplane hangar, or retail showroom.

What Are the Best Waterproofing Options for Commercial Floors?

Several moisture-mitigation products work well beneath commercial epoxy systems:

  • Epoxy moisture vapor barriers – penetrate deeply into the slab to block vapor transmission.
  • Polyurethane waterproof membranes – flexible and crack-resistant, ideal for areas with structural movement.
  • Cementitious waterproof coatings – add strength and serve as an underlayment for heavy-duty epoxy floors.

The right solution depends on your substrate condition, MVER levels, and intended traffic load. Our experienced installers tailor each project to meet your performance requirements and safety standards.

Can Waterproofing Extend the Life of Your Floor System?

Absolutely. By reducing vapor intrusion and strengthening the bond, waterproofing can add years to your floor’s lifespan. It also makes ongoing maintenance easier—cleaning is more efficient, and surface integrity remains intact even under constant use. For facility managers, this translates to fewer repairs, reduced downtime, and better ROI over the floor’s lifetime. When combined with scheduled maintenance, routine inspections, and a commercial epoxy floor reseal as needed, waterproofing becomes a key part of a long-term, cost-effective floor management plan that keeps your surface performing at its best.

Is Waterproofing Under Epoxy Worth It?

In our experience, waterproofing under commercial epoxy floors is one of the best long-term investments you can make—especially if your facility experiences humidity, temperature fluctuations, or water exposure. It’s not just about preventing damage; it’s about preserving performance, appearance, and safety for years to come.

If you’re unsure whether your concrete needs moisture protection, we can help. Our team provides on-site MVER testing, substrate evaluation, and tailored system recommendations for your industry. Call us today at (602) 254-3363 to schedule a free commercial floor consultation. Let’s design a flooring system that performs under pressure—and stays beautiful for the long run.

FAQs About Commercial Epoxy Floor Coatings

A professionally installed commercial epoxy floor can last 10–20 years, depending on traffic levels, environmental conditions, and how well the underlying concrete is maintained. In high-demand facilities like warehouses, auto shops, or manufacturing plants, using epoxy mortar layers and polyaspartic topcoats can significantly extend lifespan. Routine cleaning and periodic recoating ensure long-term performance and lower lifecycle costs.

Yes—recoating is often a cost-effective option as long as the existing system is structurally sound. We use diamond grinding or shot blasting to remove weak layers, repair cracks, and create a fresh mechanical profile before installing a new epoxy or polyaspartic coating. Adhesion testing is performed to ensure the new system bonds correctly and performs like new.

Epoxy offers excellent compressive strength and is ideal for manufacturing, warehouse traffic, and impact zones. Polyaspartic, on the other hand, is UV-stable, chemical-resistant, and fast-curing, allowing facilities to return to service within hours—not days. Many businesses benefit from hybrid systems where we install an epoxy basecoat topped with a polyaspartic finish for maximum durability and speed.

Most polyaspartic systems can be returned to light foot traffic within 4–6 hours and full service within 24–48 hours. Epoxy coatings typically require a longer cure window, depending on temperature, humidity, and thickness. We always plan installations around your schedule to minimize downtime for warehouses, retail environments, and service bays.

Proper preparation is essential for long-term adhesion. We use industrial-grade diamond grinders or shot blasters to remove contaminants, open the concrete pores, and eliminate any glossy residues. Cracks, joints, or spalling areas are repaired using polymer-enhanced mortars. Once clean and profiled, we perform adhesion tests to verify readiness for coating.

Yes. We can incorporate anti-slip aggregates, quartz, or traction enhancers to meet your required slip-resistance rating. This is especially important for restaurants, medical facilities, automotive shops, and industrial workflows where liquids or oils are present. We tailor each system to your safety needs.

Maintenance is simple—sweep the floor daily to remove debris and clean with a non-abrasive degreaser as needed. Unlike tile or bare concrete, epoxy systems are seamless and non-porous, making them highly resistant to stains, chemicals, and oils. A periodic deep clean or light recoat every few years keeps it looking and performing like new.

Heavy forklift traffic, chemical exposure, UV exposure, substrate moisture, and cleaning habits all influence longevity. Using high-performance materials—such as epoxy mortar base layers and UV-stable polyaspartic topcoats—helps your floor withstand impact, abrasion, and daily operational stress.

Yes. We perform Moisture Vapor Emission Rate (MVER) testing to confirm the concrete slab is within acceptable limits. High vapor levels can lead to bubbling, delamination, or premature wear. If moisture levels are elevated, we install a vapor barrier primer designed for industrial use.

These systems are engineered for high-traffic environments and are widely used in warehouses, retail stores, medical centers, automotive facilities, showrooms, restaurants, and manufacturing plants. Their seamless, hygienic, and chemical-resistant properties make them ideal for any business that needs a clean, professional, long-lasting flooring solution.

About AZ Garage Floors

AZ Garage Floors is a family-owned concrete coating company serving Buckeye, Surprise, Peoria, Avondale, and Phoenix. With decades of combined experience and hundreds of residential and commercial installations, AZ Garage Floors offers a full spectrum of garage floor coatings — from decorative residential systems (solid color epoxy, Granitex chip systems, metallic epoxy) to industrial commercial solutions (epoxy mortar, heavy-duty polyaspartic, chemical-resistant and anti-slip systems). The company utilizes commercial-grade 2-part resin products, thorough substrate preparation, and performance-based specifications to ensure longevity and safety. AZ Garage Floors offers residential warranty options and commercial warranty terms tailored to the project’s scale and usage.

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