How Often to Seal Concrete in Seattle, and How to Tell When It's Time
Last Updated:Sealer doesn't last forever, and in Seattle's climate it wears faster on some surfaces than others. Reseal too rarely and water, oil, and freeze-thaw cycles get into the concrete. Reseal too often with the wrong product and you build up a cloudy, slippery film. This guide covers timing: a simple test to see whether your sealer is still working, typical reseal intervals by surface, the warning signs, and the best weather window for the job. If you'd rather hand it off, see our concrete sealing service. To choose a product, read the concrete sealer comparison for Seattle.
The water-drop test
This is the quickest way to tell whether a penetrating sealer is still protecting the slab. It takes five minutes and a cup of water.
- Pick a few test spots: a high-traffic area (tire tracks, the main walking path), a shaded spot, and a low-traffic corner.
- Make sure the slab is dry and hasn't been rained on for a day or so.
- Pour or sprinkle a little water on each spot.
- Watch for about a minute. If the water beads up or sits on top, the sealer is still working. If it soaks in and the concrete darkens quickly, that area needs resealing.
- Compare the spots. It's common for tire tracks and walking paths to fail first while corners still bead. Treat the whole surface so the color stays even.
Film-forming sealers, such as acrylics on stamped or colored concrete, show wear differently. Look for dull or worn patches, flaking, or white, cloudy areas rather than relying on beading alone.
Sealing schedule by surface
These are typical ranges. Your sealer's label, sun and shade, and how much traffic the surface gets will move them. When in doubt, test.
| Surface | Common sealer type | Typical reseal interval | Notes |
|---|---|---|---|
| Driveway (broom finish) | Penetrating (silane or siloxane) | About every 3 to 5 years | Tire paths wear first; test them |
| Stamped or colored patio | Acrylic, often with anti-slip additive | About every 2 to 3 years | Sealer protects color and pattern |
| Exposed aggregate | Penetrating or acrylic | About every 2 to 5 years, by product | Acrylic deepens stone color but wears sooner |
| Walkways and steps | Penetrating | About every 3 to 5 years | Keep traction; avoid glossy films on steps |
| Shaded or north-facing slabs | Penetrating | Test yearly | Constant damp and moss wear sealer faster |
| Garage floor | Penetrating, or a coating system | Per product | Hot tires and road salt shorten life |
Several things shorten a sealer's life in Seattle: constant damp on shaded slabs, moss and the scrubbing or pressure washing used to remove it, road grit and de-icers on driveways during cold snaps, and summer sun on south-facing patios. High-pressure washing held close to the surface can strip a penetrating sealer as well as dirt, so retest after a deep clean.
Other signs concrete needs resealing
- The surface darkens immediately and stays dark long after rain.
- Oil, leaf, or rust stains soak in instead of wiping off.
- Stamped or stained color looks faded or chalky.
- White deposits (efflorescence) appear as moisture moves through the slab.
- Moss and algae come back faster than they used to after cleaning.
- Small surface flakes or pitting appear after cold snaps, an early sign of freeze-thaw damage. Our freeze-thaw protection guide explains why.
The best time to seal in Seattle
Timing is the hardest part in the Pacific Northwest. Sealers need a clean, dry slab and a dry stretch afterward, within the temperature range on the label. Late summer and early fall are usually the best window. The concrete has had the summer to dry out, and a fresh coat goes on just before the rainy season, when it matters most. Late spring works too, once the slab has dried from winter.
Clean first. Remove moss, mildew, and stains, then let the slab dry for a day or two of dry weather before sealing. Our moss and mildew removal guide covers the cleaning step. New concrete needs to cure before it is sealed. Many products call for waiting about 28 days, but follow your sealer's instructions.
When not to reseal
More sealer isn't always better. If water still beads, wait. Stacking extra coats of acrylic can trap moisture and turn the surface white and cloudy, and thick films get slippery when wet. Don't switch sealer types without checking compatibility, because many products won't bond over a different one without stripping. If the surface is spalling, cracked, or worn through, sealing won't fix it, and repair or resurfacing comes first. Sealing is one part of a broader routine, covered in our seasonal concrete maintenance checklist. For help, call Seattle Concrete at (206) 552-9998.
Frequently asked questions
How often should concrete be sealed in Seattle?
Typical ranges are about every 3 to 5 years for penetrating sealers on driveways and walks, and about every 2 to 3 years for acrylic sealers on stamped or colored concrete. Shaded, damp, or high-traffic surfaces may need it sooner, so test the surface rather than relying on the calendar alone.
How do I know if my concrete needs to be resealed?
Water soaks in and darkens the concrete instead of beading, stains soak in, color looks faded, moss returns quickly after cleaning, or film sealers look dull, flaky, or cloudy. Any of these on a regularly used surface means it is time to reseal.
What is the water-drop test?
Sprinkle a little water on a clean, dry slab in a few spots, including high-traffic areas, and watch for about a minute. If the water beads or sits on top, the sealer is still working. If it soaks in and darkens the concrete quickly, the surface needs resealing.
When is the best time of year to seal concrete in Seattle?
Late summer and early fall are usually best: the slab is dry after summer, and the sealer goes on just before the rainy season. Late spring also works. You need a clean, dry slab, a dry stretch of weather afterward, and temperatures within the sealer's label range.
How soon can new concrete be sealed?
New concrete has to cure first. Many sealers call for waiting about 28 days, but requirements vary by product, so follow the manufacturer's instructions for your sealer and conditions.
