DIY: How to Seal Driveway Asphalt
3 pros!
Learn the tricks of the trade to revive lackluster asphalt and extend your driveway's lifespan.
Tools & Materials:
• Cleaning brush & detergent
• Gloves
• Squeegee or brush broom
• Asphalt cleaner
• Crack filler
• Putty knife or trowel
• Asphalt sealer
Your asphalt driveway should last between 20 and 30 years. But, over time, asphalt will start to show some wear and tear — often cracking and fading — which reduces its visual appeal, functionality and your property value.
To properly maintain it, you should seal coat asphalt shortly after your driveway installation and then reapply driveway sealant every two or three years. This will help keep the drive looking like new and prevent further deterioration.
If you choose to tackle this messy home improvement chore yourself, you're sure to save some money, particularly on labor. But, keep in mind a highly rated contractor can significantly increase the quality of the seal coat job and some asphalt companies offer warranties on this type of work.
MORE: What to Consider Before Sealing Driveways
Sealing a driveway isn't too complicated, but heed the following advice to ensure you know how to seal a driveway properly and don't do more harm than good to your asphalt driveway.
First, let your new asphalt driveway cure
You need to seal your driveway after it's installed, but not right away. Wait about 90 days after the driveway installation, during fairly warm weather, so that your asphalt has a chance to harden before you seal it. In hot and dry climates, you typically only have to wait 30 days.
Check the weather before sealcoating
Humidity isn't an issue when sealing an asphalt driveway — in fact, you'll want the asphalt to be damp when you seal it — but precipitation and low temperatures will endanger the crisp, clean results you desire. Make sure the temperature will stay above 45 degrees (preferably warmer) for a few days after you seal the driveway, and be sure no rain is expected for three days after you complete the project.
Wear disposable clothes and shoes when sealing asphalt
While it's possible to seal your asphalt driveway without getting sticky black sealant all over yourself, that's unlikely to happen. Wear clothes and shoes that you're perfectly OK with destroying (or try tying plastic bags around your shoes), and wear gloves when applying the sealant to keep the seal coat chemicals off your skin.
Clean and prep your driveway
You want to make sure the driveway is as clean as possible before you seal it. If you trap any oils in between the asphalt and sealant, it can eat away at the asphalt and ruin your driveway. You also want to make sure to make any necessary repairs before you seal coat, otherwise those problems will only worsen under the new seal.
Pull all weeds and remove debris with the push broom. Next, use a pressure washer to clean out any large cracks. Clean up any oil spots with a store-bought asphalt cleaner specifically designed to remove oil stains, then scrub the entire driveway with detergent and water.
Do this right before you apply the asphalt sealer, because you want the asphalt to be damp when you do your first sealant application.
Repair cracks before you start
Sealing a cracked or chipped driveway defeats the purpose of seal coating in the first place, so be sure to repair asphalt before you begin. For most older driveways, you'll need to use a combination of a patching compound for small cracks and dents, and cold blacktop patch for deeper potholes.
Schedule in a few extra days before you seal the driveway to give these patches time to dry.
Consider what kind of seal coat you prefer
There are two main types of seal coats used by driveway professionals: Refined coal tar emulsion and asphalt emulsion.
Coal tar sealers protect your driveway from leaking oil and gas spills, are resistant to all types of weather and last longer, but are harsh on skin and smell terrible when first applied. They're also typically cheaper, but require constant stirring during the application process.
Asphalt emulsion sealers, meanwhile, are the most popular type of asphalt driveway sealer. They're easier to use, but don't protect as well against gasoline or oil and fade faster.
Talk your local hardware store expert when you buy supplies or call a professional driveway installer in your area to see what kind of sealer makes the most sense for your purpose, region and specific project.
Mix the seal coat product first
About two days before you plan on sealing a driveway, purchase the buckets of sealant and turn them upside down. This will help mix the sealer and give it a more consistent color. Also, when one bucket is about one-third full, mix most of the second bucket in with it, which will also help keep your asphalt sealer uniform in color.
A sealed asphalt driveway boosts curb appeal and keeps your drive from deteriorating. (Photo courtesy of Angie's List member Rick A. of Fort Mill, S.C.)
How to apply asphalt sealer
A thin layer of sealant works best. Applying excess sealer doesn't help, so applying a thick coat is just a waste of money. Two thin seal coats are ideal to ensure complete coverage without wasting money on too much sealer.
Pour a couple of gallons on the driveway and work in small areas, so the sealer doesn't dry too fast while you're spreading it out. Use a squeegee or brush broom to apply the sealer in overlapping ribbons across the driveway. Pull the sealer carefully to the edges with a squeegee.
Lay out the first coat in long, horizontal stripes down your driveway. After the sealer has dried (about 6 to 12 hours), apply the second coat in vertical stripes.
Keep off the driveway while it dries
Don't use your driveway at all until the second coat completely dries. This normally takes around 24 hours, but consult the directions on the sealer container for a specific drying time.
Rope off the front of the driveway or just place the empty sealer cans at the entrance to prevent anyone from accidentally driving on it until it's dry.
Editor's note: This is an updated version of an article originally published on Dec. 28, 2012.