Moisture, Rain & Concrete: Why Epoxy Floors Fail Without Proper Prep
In the Pacific Northwest, moisture isn’t just part of the forecast, it’s part of everyday life. Rain, humidity, and temperature swings all affect concrete, and when it comes to epoxy flooring, moisture is the number one reason floors fail.
At Westside Epoxy, we see it all the time: peeling coatings, bubbling surfaces, cloudy finishes, and premature breakdown all caused by skipping or rushing the prep work. The truth is simple: without proper moisture mitigation, even the best epoxy system won’t last.
Why Concrete Holds Moisture
Concrete may look solid, but it’s actually porous. Moisture from rain, groundwater, and humidity can move up through the slab as vapor. In areas like Gig Harbor this is especially common due to:
Frequent rainfall
High year-round humidity
Older slabs without vapor barriers
Coastal and near-water environments
When moisture vapor pushes up through concrete, it creates pressure under the epoxy coating. If that pressure isn’t managed correctly, the epoxy can’t bond and failure is only a matter of time.
What Happens When Moisture Isn’t Addressed
When epoxy is installed without proper moisture prep, you may see:
Peeling or delamination
Bubbling or blistering
Cloudy or discolored finishes
Soft or tacky epoxy that never fully cures
These issues often don’t show up right away. Many floors look great at first then fail months later, long after a DIY kit or rushed install is finished.
Why Acid Etching & DIY Kits Don’t Work in the PNW
Many off-the-shelf epoxy kits rely on acid etching or basic cleaning instead of mechanical prep. In dry climates, this might work temporarily. In the Pacific Northwest, it almost always fails.
Acid etching does not:
Remove deep contaminants
Open the concrete profile consistently
Address moisture vapor transmission
That’s why professional epoxy installation, especially in wet climates, requires mechanical grinding and moisture testing, not shortcuts.
What Proper Moisture Mitigation Looks Like
At Westside Epoxy, moisture mitigation is built into our process from day one.
1. Moisture Testing
Before any epoxy goes down, we test the concrete for moisture vapor transmission. This tells us whether a standard system will work or if a moisture-mitigating primer is required.
2. Mechanical Grinding
We use industrial grinders to open the concrete pores, remove contaminants, and create the correct surface profile for epoxy adhesion. This step is critical and cannot be skipped.
3. Moisture-Mitigating Primers
When needed, we apply specialized moisture mitigation epoxy primers designed to block vapor transmission and stabilize the slab before the main coating system is installed.
4. Proper Cure & Environmental Control
Temperature and humidity are monitored throughout the installation process to ensure the epoxy cures correctly — especially important during wet or cool months.
Why Prep Matters Even More for Commercial Spaces
In commercial and industrial environments, floors see heavier use, more traffic, and greater exposure to water, oils, and chemicals. Moisture-related failure in these spaces can lead to:
Costly downtime
Safety hazards
Re-coating expenses
Damage to equipment or inventory
Proper moisture mitigation protects your investment and ensures your floor performs the way it’s supposed to, for years and not months.
Built for the Pacific Northwest
Epoxy flooring works extremely well in the PNW when it’s installed correctly. The key is understanding how moisture behaves in concrete and taking the time to prep the slab properly.
At Westside Epoxy, we don’t rush installs or cut corners. We build floors that are designed specifically for PNW conditions, whether it’s a residential garage or a high-traffic commercial workspace.
Don’t Let Moisture Ruin Your Floor
If you’re considering epoxy flooring and want it done right the first time, moisture mitigation isn’t optional, it’s essential.
