How to Seal an Asphalt Driveway
Updated: Nov. 11, 2022
Introduction
We'll show you how to clean and prepare the driveway so you get the longest life and best protection from asphalt driveway sealer.Driveway Sealing Preparation
There are several kinds of driveways for homes, but one of the most popular choices is an asphalt driveway. It can last for almost 30 years, even adding a little curb appeal to your home. But you can’t achieve that long life span unless the driveway was installed properly and you perform regular maintenance, like filling cracks annually and driveway sealing when needed.
Driveway sealing preparation can take a full day (including drying time), and it’s tedious. The driveway sealer application phase is much faster, taking only a few hours per coat for a typical driveway. Most driveway sealer manufacturers recommend two coats with a minimum drying time of eight hours between coats, so this driveway sealing project will fill an entire weekend. Sealing it is also an important step for winterizing your driveway.
The best asphalt driveway sealer materials cost about $100, but you’ll save about $200 in labor over a professional job. A power washer speeds the cleaning process, but you can do the job without it. In addition to a squeegee or application brush, you’ll need a broom, drill, mixing paddle, duct tape, dashing brush and poly sheeting to protect painted surfaces.
Avoid these common driveway sealing mistakes
- Depending on the sealer to fill cracks. It won’t. Fill them properly before applying sealer.
- Failure to clean and prep the driveway before applying the sealer. If you don’t want to spend time cleaning the driveway, you may as well skip the sealer too, because it won’t stick to a dirty driveway.
- Failure to stir properly. Don’t depend on a stir stick. It simply won’t blend the water and solids enough to get a consistent mixture.
- Use of the wrong applicator. Using a brush when the manufacturer specifies a squeegee (or vice versa) will cause premature sealer failure.
- Applying asphalt sealer too often. Too much sealer will flake off. Wait until you begin to see asphalt aggregate before you apply a new coat of sealer.
Buying the Right Materials
Driveway sealer is available in various grades and price ranges. Some bargain products contain almost 50 percent water and have lower coverage rates and a correspondingly shorter guarantee, so they’re not the most cost-effective solution over the long term. Use one of them if you’re trying to spiff up the driveway before selling your home. Premium products, on the other hand, are made with higher quality resins and UV stabilizers and contain filler and elastomeric material, so they last longer and carry a longer guarantee.
Manufacturers also make different formulas for different driveway sealing conditions: one formula for newer driveways in good condition and another formula for older driveways that haven’t been well maintained. The two formulas also vary in their coverage, so read the labels carefully and choose the correct sealer and quantity for your particular driveway. Follow the manufacturer’s directions for the type of applicator to use (brush or squeegee). Using the wrong one can cause premature failure. You’ll also need liquid driveway cleaner/degreaser to remove oil and tree sap. If your driveway has visible oil stains, pick up a bottle of oil spot primer.
Check the Weather Before you Start
You’ll need at least two days of dry weather to seal your asphalt driveway. Temperatures must be above 50 degrees F during application and throughout the night. And, it’s best to avoid scorching-hot sunny days (the sealer may dry too fast). If you ignore the weather forecast, you may see $100 worth of sealer wash away in a heavy rain.
Project step-by-step (8)
Start with Cleaning and Priming
Use the soap nozzle on your power washer or a garden hose applicator to apply the driveway cleaner. Then scrub the entire driveway with a stiff-bristle push broom.
Even if you think your driveway is clean, trust us, it isn’t. Exhaust gas contains combustion byproducts that deposit a light, sometimes oily film on your driveway. That film, along with dirt and tree sap, must come off if you want the sealer to stick. So clean the driveway first (Photo 1).
Rinse with a Strong Stream
Flush the soap and dirt residue with a 40-degree power washer nozzle or a strong stream of water from your garden hose. Next, rinse the driveway with clear water (Photo 2). Let the driveway dry completely before applying the sealer. Then perform a final sweep with a push broom.
Pretreat the Oil Stains
Pour the oil spot primer on the damaged areas and brush it into the pores with a disposable chip brush. Apply a second coat to heavier stains. Let the primer dry fully before applying the driveway sealer. Treat any oil stains with an oil spot primer (Photo 3).
Mask, Stir and Trim
Start the mixing paddle near the top of the pail and slowly lower it into the contents settled at the bottom. Cycle the mixing paddle up and down while it spins to combine the water and solids into a smooth consistency. Choose an area on the driveway for mixing and cover it with poly sheeting to protect against spills (dried spills will show through the sealer). Remove the pail lids and cut a small hole in the center of one lid. Use that lid to prevent splashing during mixing. Stir until the mixture is smooth (Photo 4).
Cut in the Edges
Dip the dashing brush into the sealer and apply a liberal coating to all four edges of the driveway. Don’t spread it too thin; you want it to fill in all the pores. Next, cut in all four edges of the driveway with a large dashing brush (Photo 5).
Stage the Pails
Guesstimate the coverage of each pail and stage each additional pail along the driveway. That saves time and reduces the need to walk through wet sealer to get the next pail. Driveway sealer will splash onto your garage door and sidewalks as you pour it. And it’ll get all over your shoes and clothes. It’s very difficult (often impossible) to remove later, so wear old work clothes and shoes. Mask the garage door with poly sheeting and apply strips of duct tape to concrete walks where it butts up to the asphalt. Then stage the pails equally down the driveway (Photo 6).
Pour onto the Driveway
Start at the top left or right edge of the driveway and pour the sealer in an upside-down U-shape pattern. Pour the sealer onto the driveway (Photo 7).
Spread the Sealer
Start at one leg of the upside down ‘U’ and apply even pressure to spread the puddle across the driveway and down along the opposite leg. Then pick up the excess sealer on the down leg and start the next row. Then spread the puddle with a squeegee or broom, depending on the manufacturer’s directions (Photo 8). Pour enough sealer to maintain a puddle in front of the applicator tool.
When you reach the bottom of the driveway, cap the remaining pails and clean the squeegee or brush. Set the empty pails along the curb to prevent cars from ruining the job. Then let the sealer dry overnight.
Repeat the sealer application the next day. Let the sealer dry for 48 hours before driving on it (better safe than sorry). Don’t ask how we learned that lesson.
Driveway sealers: Real protection or just black paint?
Some asphalt driveway companies tell their customers that driveway sealer is a waste of money, that it’s cosmetic and doesn’t do anything to extend the life of the asphalt.
It’s true that driveway sealer can’t replace the liquid asphalt (oil/tar) that oxidizes and bakes out of the mixture from heat and sun exposure. But a high quality sealer can dramatically reduce future heat and UV damage. Plus, it seals the pores to prevent aggregate breakup damage caused by water penetration, freeze/thaw cycles and chemicals. So it really does extend the life of your driveway.
