Concrete Driveway Sealer: Which One to Use and How Often

What is the best concrete driveway sealer?

A breathable penetrating sealer. For a broom-finished driveway, that’s a siloxane like PS110 or a siliconate like PS102. For a dense, smooth driveway that gets salted every winter, it’s a silane like PS109, and for a smooth driveway, the PS101 siliconate.

The NRMCA recommends a silane or siloxane based breathable concrete sealer (opens in a new tab) to protect driveways from freeze-thaw scaling. A film-forming sealer is a poor fit outside: Iowa State’s review of sealers flags barrier coatings for potential influences on skid resistance (opens in a new tab) and early wear under traffic.

PS101, PS109 and PS110 data sheets, PS102 application guidelines and product page, Concrete Sealers USA FAQ

PS110 is water based, goes on milky white and dries clear. Its data sheet reports a 94.0% cut in chloride absorption in a northern exposure test and 98.9% in a southern one, and no scaling in the ASTM C672 freeze-thaw test.

Which driveway sealer fits your concrete?

Match it to the finish. Rub your hand across the driveway: a rough, ridged surface is a broom finish, and a smooth, tight surface is troweled or dense. Then put a few drops of water on it to see how fast it soaks in.

• Broom finish, soaks in fast. PS110 or PS102. Both are made for porous, broom-finished concrete. PS102’s application guidelines say it can also cure new broom-finished concrete once the bleed water is gone.
• Smooth finish. PS101. Its data sheet calls it a general purpose sealer for smooth concrete and lists driveways, garage floors and pool decks.
• Dense or smooth, salted every winter. PS109. It’s a silane, which penetrated deeper than siloxane in a study cited by Iowa State’s review: 0.008 to 0.08 inch (opens in a new tab), against less than 0.02 inch for siloxane.
• Water beads and won’t soak in. Don’t seal yet. The surface is already sealed or too dense, and a penetrating sealer will sit on top.

PS109’s data sheet reports an 88% cut in chloride absorption in a northern exposure test and 97% in a southern one. It’s solvent based with a flash point of 149°F and comes only in a 5 gallon size, so it suits a large driveway, with good airflow and no sparks or flames nearby.

For smooth concrete, PS101 covers the most ground per gallon, and broom-finished slabs can take PS102. The penetrating vs topical guide explains the chemistries.

How much driveway sealer do you need?

Divide the driveway’s area by the coverage rate for your sealer and finish. A driveway measured at 600 square feet, sealed with PS110 at 150 to 200 square feet per gallon, needs 3 to 4 gallons.

The data sheets say coverage rates are approximate and depend on how porous the concrete is. Buy for the low end of the range on an older, rougher slab, and do the small test area the data sheets require first: it tells you your real rate.

How to seal a concrete driveway

Fix the cracks, clean the slab, let it dry, then spray the sealer on until the concrete stops taking it in. Here’s how to seal concrete driveway slabs, following the PS-series instructions:

1. Fix the cracks first

   Fill every crack before any sealer goes down, because the slab kit’s data sheet warns that sealers stop its urethane from bonding. The driveway crack repair guide covers it.

2. Clean the driveway

   Sweep and wash off dirt, oil, mildew and old curing compounds. The data sheets want the surface free of all of them.

3. Let it dry

   Allow 1 to 3 days after washing or heavy rain, per the sealer’s application guidelines. The surface should be dry, not damp.

4. Check the forecast

   Pick a day between 40°F and 95°F, with no rain expected for 12 hours after you finish. The temperature limit applies through the drying period too.

5. Do the water drop test

   Put a few small drops of water on the slab. If they soak in within 3 to 5 minutes, it can take a penetrating sealer.

6. Test a small area

   Seal a small patch the same way you’ll do the whole driveway and let it dry. Every one of these data sheets requires a test first.

7. Spray to the point of rejection

   Use a low pressure sprayer and work in small sections, keeping a wet edge. Apply until the concrete stops soaking it up; it should be absorbed within 10 minutes without puddles.

8. Brush out puddles

   Spread any pooled sealer with a broom or roller. Excess can dry to a white residue.

9. Keep off it

   Stay off for 6 to 12 hours. Wait a full day before driving on it, and 24 to 48 hours after PS109.

A second coat is only for porous concrete that’s still thirsty. The PS101 guidelines allow a light second coat any time after 24 hours, only if water drops still soak in within 3 to 5 minutes. The sealer drying time guide has the waits for each product.

How often to seal a concrete driveway

Every few years, when water stops beading. The sealer maker’s FAQ says penetrating water repellents can last up to 5 to 7 years or more, and that outdoor slabs fall at the low end because of sun, traffic and weather.

The best guide to how often to seal concrete driveway slabs is a water drop. Each spring, sprinkle a little water on the driveway in the tire tracks and in a spot that sees little traffic. If it soaks in instead of beading, it’s time to reseal; over an old penetrating sealer you can reapply once drops soak in.

Research on silane points to a long life. Iowa State’s review cites a 2016 study that found every silane sealer under 12 years old still penetrating more than 1/8 inch (opens in a new tab), dropping to 68% after 15 years and 16% at 17 to 20 years.

When is the best time to seal a driveway?

Late summer, after a few dry days. The NRMCA calls late summer with a few dry days before application (opens in a new tab) an ideal time, because the concrete is dry and the sealer has time to work before de-icers arrive.

The data sheets set the limits: 40°F to 95°F during application and drying, a dry surface, and no rain for 12 hours afterward.

Should you seal a new concrete driveway?

Yes, after it has cured. The data sheets say concrete should ideally be at least 28 days old or fully cured before a penetrating sealer goes on, and PS102 is the one exception: its guidelines allow it as a curing aid on fresh broom-finished concrete.

The first winter matters most. The NRMCA says to avoid de-icing chemicals in the first winter (opens in a new tab) and to use only moderate amounts after that.

How do you protect a sealed driveway in winter?

Go easy on salt and pick the right kind. The NRMCA says calcium chloride and sodium chloride (rock salt) are acceptable in moderate amounts, and to never use ammonium sulfate, ammonium nitrate or magnesium-based de-icers (opens in a new tab).

It also says to hose off the salt cars drag onto driveways and garage slabs. Iowa State’s review cites a recommendation to limit aggressive salts, especially magnesium and calcium, to times and temperatures when they’re needed for safety, typically below 15°F.

Which driveways shouldn’t you seal?

Don’t seal a driveway that has moved, has an old coating or is asphalt. A sealer protects sound concrete; it doesn’t fix damage.

• Cracks wider than 1/4 inch, edges higher on one side, or sunken panels. Find the cause first with the large cracks guide or the sinking slab guide. If the cracks line up with cracks in your foundation, talk to a structural engineer.
• A driveway with an old topical coating. Remove it first; the sealer removal guide covers stripping.
• Asphalt. These sealers are made for concrete and masonry only.
• Badly scaled or flaking concrete. The data sheets say the sealers won’t remediate structurally unsound surfaces. The spalling and scaling guide covers repair.

Once the cracks are filled, the sealing after crack repair guide covers the wait before sealing. Garage slabs have their own needs, covered in the garage floor sealer guide, and the sealing guides cover the rest.