How to Seal an Asphalt Driveway
Sealing a driveway isn't a difficult task in and of itself, but without doing the necessary preparation before applying the sealer, your project can very easily go wrong, and you can find yourself with an improper seal.
Putting a sealant over an asphalt driveway keeps out moisture, keeps large cracks from forming, and is a general form of preventative maintenance. If done well, a proper sealcoating can penetrate pre-existing cracks to seal them before they expand and can even improve the overall appearance of asphalt to a point where it looks like new.
Step 1 - Inspect the Surface
Start by first taking a good look at your driveway surface. The surface can be marred by everything from bird poop and oil stains to cracks and potholes. You’re going to want get these out before putting on any sealant. These can cause the sealant to be less effective.
Step 2 - Address the Stains
Sweep away any large, dry debris using a broom or a hose. Lingering stains from oil and other tough substances will require a little more elbow grease. Warm water, soap, and a scrub brush should be enough to wash most driveways. You may need to apply a de-greaser for some oil stains
Step 3 - Repair Cracks
The next obstacle is cracks. You must fill in cracks prior to sealing and also allow enough time for the filler to dry. Smaller cracks can usually be taken care of with a liquid sealer. However, larger cracks will need asphalt repair caulk and may need more than one application. During the drying process, the caulk loses moisture and may shrink. A second application will make it flush with the driveway surface.
For deep cracks, place a foam backing in the crack and then cover with the asphalt caulk.
Step 4 - Fill Potholes
Potholes are much larger and severe than any cracks, and no amount of asphalt caulk is going to take be enough to fix a pothole.
Instead, you're going to need to use cold patch or quick concrete patching product for actual asphalt repair. It’s basically ready-to-use asphalt and simply needs to be shoveled and compacted into the hole. As easy as the cold patch makes the process, you still may need to do it more than once, as settling can cause the surface to shift so it is no longer flush with the rest of the driveway.
Step 5 – Choose the Right Window to Apply
You're going to need two or three days of good sunny weather both prior to application and during your sealcoating. It takes a while for the seal to properly dry, and any amount of rain will erode at the sealant and eventually wash it away.
Step 6 – Choose a Sealant Variety
There are four types of sealant available: tar emulsion, asphalt-emulsion, latex-acrylic, and rubber sealant with titanium fortification.
Tar emulsion is cheap, but it’s hard to apply and needs constant stirring to prevent solidification when not being applied.
This option is a little more expensive, but it is the most popular option for homeowners. Asphalt-emulsion lasts longer than tar and provides better protection.
Latex-acrylic provides even better protection and dries faster, but it’s also expensive, usually more than double that of an asphalt-emulsion sealer.
Rubber with Titanium
The absolute best option for sealcoating asphalt is a liquid rubber sealer with titanium fortification. This kind of sealer costs about $500 for 5 gallons, compared with $65 for 2 gallons of the latex-acrylic.
Step 7 – Apply the Seal
Regardless of which sealer you choose, they are all generally applied the same way. You'll need a specialized tool that has a long handle and a squeegee and one end and a brush at the other. Pour about a foot-long strip of sealant onto the pavement, use the squeegee to spread it, and the brush to make it even. Start at one end and work your way to the other. Some sealer types can be applied with a paint roller if you prefer that way.
Let it set for about 12 hours to dry and then apply a second layer. Keep people, pets, and vehicles off of the asphalt for at least a day so that any additional coats can dry properly.
Looking for other ways to improve curb appeal? Get some color with sidewalk staining.