Why You Shouldn’t Use Water-Based Sealers Outside (and What to Do If You Already Have One)
- Damian Bagby
- Sep 3
- 3 min read
Concrete sealing sounds simple — spray or roll and you’re done. But in Colorado’s sun, freeze-thaw cycles, and salty snowmelt, the wrong sealer will cost you time and money. Here’s why water-based sealers usually aren’t the best choice for exterior concrete in Denver, and what you can do if your surface already has one.
Why water-based sealers fall short outside
They sit on the surface. Water-based sealers typically form a surface film rather than penetrating. That film can wear, flake, or peel under heavy sun, vehicular traffic, and freeze-thaw stress.
UV and freeze-thaw vulnerability. Denver’s strong UV and seasonal temperature swings accelerate surface breakdown — water-based products often lose gloss and protection faster than solvent options.
Shorter lifespan. Expect water-based sealers to need replacement more often (sometimes every 1–2 years) versus properly applied solvent-based acrylics, which tend to last longer on exterior stamped and decorative concrete.
Aesthetic problems. Water-based products can dry cloudy or uneven on older surfaces or where moisture is trapped underneath, leaving a blotchy look.
How to tell if your surface has a water-based sealer
Do a simple test (safely):
Pick an inconspicuous spot.
Put on gloves and eye protection. Xylene is a strong solvent — use it carefully and outdoors.
Place a small drop of xylene on the spot and rub gently with a rag:
If the sealer softens or comes off, it’s likely solvent-based (xylene dissolves many solvent sealers).
If the sealer does not soften, it’s likely water-based or otherwise cured into a non-solvent-soluble film.
Important safety note: xylene is flammable and toxic — use gloves, eye protection, and good ventilation. If you’d rather not use chemicals, book a quick inspection with a pro (we’ll test it for you).
What to do if you have water-based sealer outside
Option A — If it’s still holding up
Monitor it. If there’s no flaking, heavy wear, or clouding, you can delay an aggressive removal and plan for a reseal with a more durable product when the next reseal window comes up.
Top with the right product? Avoid applying a solvent sealer directly over a water-based film — that mismatch often fails. It’s better to remove or mechanically profile first.
Option B — If it’s failing (peeling, cloudy, or uneven)
Don’t coat over failing layers. New sealer over a failed water-based film will look bad and fail fast.
Removal / surface prep methods professionals use:
Mechanical grinding — evens the surface and removes thin films.
Sandblasting (abrasive blasting) — removes thick or stubborn coatings; excellent when you want to restore stamped texture.
Chemical stripping — specific strippers can break down certain water-based films, but they require care and proper disposal.
After removal or profiling, the right sequence is: clean → repair (if needed) → allow to dry → apply solvent-based acrylic sealer (our usual choice for Denver exteriors).
Why we prefer solvent-based acrylics for Denver exteriors
Better color pop & gloss retention under UV.
Stronger film formation and longer life against traffic and weather.
Proven performance on stamped decorative surfaces when applied correctly (two thin coats, rolled/rolled-out evenly).
Quick DIY checks & homeowner tips
If your surface beads with water but looks cloudy or feels tacky after the sun, call a pro.
Don’t seal before a rain or when temps are below the manufacturer’s recommendation (usually under ~50°F).
For pool decks and slopes, ask for a traction additive (we broadcast silica sand into the sealer).
Bottom line
Water-based sealers can be tempting — lower odor, easy application — but for exterior, decorative, and stamped concrete in Denver, they often underperform. If you’re unsure what you have, we’ll test, inspect, and recommend the right path: repair, removal, or reseal with a long-lasting solvent-based system.
Call Concrete Sealers at (720-499-4220 or get a free on-site estimate to test your sealer and plan the best next step.
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