Concrete Sealing in Kent, WA

What our climate does to concrete

Exterior concrete here spends much of the year wet. Water soaks into the pores of untreated slabs and carries dirt, tannins from fallen leaves and fir needles with it. Shady areas grow moss and algae that make walkways slick. On colder nights, water inside the concrete can freeze and expand, slowly breaking down the surface into scaling and pitting. A good sealer limits how much water gets in, which slows all of that damage.

Types of sealers

Penetrating sealers such as silanes and siloxanes soak into the concrete and react to form a water-repellent barrier inside the pores. They do not change the look or add sheen, they keep the surface breathable and they do not make concrete slippery. They are our usual choice for walkways, steps and driveways.

Topical sealers such as acrylics form a thin film on the surface. They can enhance color with a wet look and add a satin or gloss sheen, which is popular on stamped and colored patios. They do need reapplication more often and may require a grip additive.

Cleaning comes first

A sealer locks in whatever is on the surface, so we clean thoroughly first. That means pressure washing with a surface cleaner, treating moss and algae, removing rust and organic stains where possible and letting the slab dry. We check that the concrete is dry enough for the sealer we plan to use, which in our climate means watching the forecast closely.

Surfaces we seal

• Backyard patios and pool decks.
• Front walkways and entry steps.
• Stamped and colored concrete.
• Exposed aggregate driveways and paths.
• Garage aprons and carports.
• Commercial sidewalks, loading areas and plazas.

Stamped and decorative concrete

Stamped patios lose their color and pattern definition when the original sealer wears away. Resealing with a quality acrylic restores the color and helps protect the surface. If an old sealer has turned white or cloudy, a common problem when moisture gets trapped beneath it, we can strip or re-dissolve it before applying a fresh coat.

Cracks and joints

Sealing works best when cracks and joints are addressed too. We clean and fill cracks with flexible sealant so water does not run under the slab and wash out the base. Filling joints also reduces weed and moss growth.

Timing the work

Most sealers need a dry slab and a dry forecast for application and cure. Late spring through early fall gives the most reliable windows, though we can often find dry stretches in other months. We schedule jobs with that in mind and will move a date rather than seal over damp concrete.

Safety on wet surfaces

A glossy topical sealer can become slick when wet, which matters on steps and sloped walks during the rainy months. We mix a fine grit into topical sealers on walking surfaces and recommend penetrating products where traction is the priority. Our goal is protected concrete that is still safe to walk on in a downpour.

How often to reseal

Penetrating sealers usually last several years. Topical acrylics on patios usually need refreshing every two to three years, depending on sun and traffic. We can set up reminders so your outdoor concrete stays protected without you having to track it.

Interior sealing

We also seal interior concrete in basements, storage rooms and shops where a full coating is not needed. A clear sealer controls dust and makes the floor easier to sweep, and it can be a cost-effective step before a future coating.