If you own a concrete driveway in the Denver metro, sooner or later someone will tell you to seal it. Is it worth it, which sealer should you use, and how often does it need to be done? The short answer: yes, sealing is one of the cheapest ways to protect a Colorado driveway, but the type of sealer and the timing matter more than most homeowners realize.
Here is what we tell homeowners who ask us about concrete sealing in Denver, and what the sealer manufacturers and industry guides say.
Why Colorado Driveways Need Sealing More Than Most
Concrete looks solid, but it is full of tiny pores. Water soaks into those pores, and in Colorado that water freezes and thaws dozens of times every winter. Each freeze pushes on the concrete from the inside. Add the de-icing chemicals that drip off your car all winter, and the surface starts to flake and pit. That damage is called scaling or spalling, and once it starts it cannot be reversed.
Euclid Chemical, a major concrete products manufacturer, notes in its winter durability bulletin that de-icers speed up scaling and surface deterioration. In the Denver area the biggest culprit is the magnesium chloride that road crews spray on highways and that rides home on your tires. We go into detail on that in magnesium chloride and your concrete driveway.
A good sealer slows water and salt from getting into the concrete. Less water in the pores means less freeze-thaw damage, and less salt means less scaling.
The Two Main Types of Concrete Sealer
Almost every concrete sealer falls into one of two groups, and they work very differently.
Penetrating sealers (silane and siloxane)
Penetrating sealers soak into the concrete and react inside the pores, so water beads up and rolls off instead of soaking in. They do not leave a film on top, so the driveway looks the same as before and does not get slippery. Concrete Network lists sealing driveways among their most common uses, and Euclid Chemical calls penetrating sealers the preferred solution for concrete exposed to freeze-thaw and de-icers.
Because they work below the surface, penetrating sealers last a long time. Concrete Network puts them at usually 5 to 10 years, with silanes at the longer end and siloxanes typically 5 to 7 years. Driveways that see a lot of de-icing salt wear out faster.
Film-forming sealers (acrylics and urethanes)
Film-forming sealers sit on top of the concrete and create a coating, often with a gloss or "wet look." They are popular on stamped concrete and colored concrete because they make the color pop. The tradeoff is that the film wears away with traffic and sun. PROSOCO, a sealer manufacturer, notes that acrylics often need to be reapplied sooner, and some film-forming products need recoating within 12 to 18 months.
A glossy film can also get slick when wet or icy, which is worth thinking about on a sloped driveway.
What We Recommend for Denver Driveways
The right product depends on what kind of concrete you have. Here is the simple rule we follow.
Regular slab driveways: a water repellent salt protector
For most standard broom-finish driveways, we recommend a penetrating water repellent, often called a salt protector, instead of a glossy sealer. The product we use is TK Salt Protector Plus, a low-VOC silane/siloxane blend made to protect concrete from de-icing salts and freeze damage. It soaks into the concrete instead of sitting on top, so your driveway looks the same afterward and keeps its traction. There is no shiny film to wear off or get slick in the snow.
We apply two even coats, and it protects the driveway for about 3 to 4 years. The manufacturer told us the product is designed to last 5 years, but we recommend reapplying after 3 or 4 winters depending on wear and sun exposure. Read more about it on our salt protector for concrete driveways page and in the benefits of using a salt protector on your driveway.
Decorative driveways: a good sealer
For decorative concrete, such as colored, sand finish, stamped, or stained driveways and patios, we recommend a good quality sealer. On these surfaces the sealer is part of the finish. It brings out and protects the color, guards the surface against salt and stains, and keeps the finish looking fresh. Those surfaces need a fresh coat on a regular schedule, and for stamped concrete we generally recommend resealing every 2 to 3 years. If your stamped patio or driveway already looks faded, read how to choose your colors for a stamped concrete project to see how color and sealer work together.
How Often Should You Reseal?
It depends on the product, how much traffic and salt the driveway sees, and how much sun it gets. A rough guide:
- Salt protector on a regular slab driveway: reapply after 3 or 4 winters.
- Sealer on colored, sand finish, stamped, or stained concrete: every 2 to 3 years, sooner if it looks dull or worn.
The easiest way to tell is the water test that Concrete Network recommends. Splash some water on the driveway. If it beads up, the sealer is still working. If the water immediately soaks in and darkens the concrete, it is time to reseal. Check the spots that take the most abuse first, like the tire paths and the area right outside the garage door where salty slush drips off your car.
When to Seal: Timing Matters
New concrete
New concrete needs time to cure before it is sealed. Rust-Oleum's instructions for its penetrating sealer call for a minimum of 28 days, and PROSOCO warns that a vapor-blocking sealer on concrete less than 30 days old can blister. New concrete is also most vulnerable in its first winter. Euclid Chemical advises against putting de-icing salts on new concrete during its first winter at all, and suggests sand for traction instead.
That is why many homeowners add a salt protector when a new driveway is poured. We offer it as an add-on for every new driveway we pour. After the job is cleaned up, we wait an additional 30 days so the concrete can fully cure and dry out, then clean the surface and spray on two even coats.
Weather
Sealer needs the right weather to soak in and cure. Rust-Oleum's application instructions, as one example, call for air temperatures between 50 and 90 degrees, humidity below 85 percent, no rain expected for 24 hours, and no application in direct sunlight. In Denver that usually means late spring through early fall, on a mild day without afternoon storms in the forecast. Fall is a popular time to seal because it gets the driveway protected right before the first snow and mag chloride of the season.
Most sealers need a day or two before you drive on them again. Rust-Oleum lists light foot traffic after 4 to 6 hours and vehicles after 24 to 48 hours.
Sealing Will Not Fix Everything
Sealer protects good concrete. It will not repair concrete that is already badly damaged. If your driveway has wide or growing cracks, sunken panels, or large areas of flaking, sealing it is like waxing a car with a bent frame. Read 7 signs your concrete driveway needs to be replaced, not just repaired to see where your driveway falls. If a section has settled, concrete replacement vs. mud jacking compares the options.
If you do replace, a well-built driveway with a strong mix holds up far better to salt and freeze-thaw from day one. See why we use 4,500 PSI concrete instead of 4,000 PSI.
DIY or Hire a Pro?
A penetrating sealer on a clean, plain driveway is a reasonable DIY project if you follow the product instructions exactly. Where homeowners run into trouble is surface prep and product choice. Sealer applied over dirt, oil, or old peeling sealer will not bond, and a film-forming sealer applied too thick or in the wrong weather can turn white, peel, or get slippery.
We also apply salt protector to driveways we did not pour. We power wash the concrete, blow it off, and apply two coats. For decorative concrete, our concrete sealing service always starts with cleaning and etching the surface, then applying the sealer. For old stamped concrete, we can often bring it back to life with cleaning, fresh color, and new sealer. For more quick answers on cure times, winter care and maintenance, see Denver concrete questions answered.