Driveway sealcoating creates a membrane that protects the concrete or other substrate from the damaging effects of the sun, gasoline, rock salt, oil, and ice.
How Long Does it Take to Sealcoat a Driveway?
Sealing a driveway should be no more than a weekend affair—with dry weather and temperatures above 50 degrees required.
Steps for Sealcoating a Driveway
Park in the street before starting this job, because you’ll have to wait a period of time while the sealant sets up, whether that’s an hour for foot traffic on a quick-dry or up to 48-hours with two coat system.
Step 1: Prep your driveway
- As a general rule, the night before sealcoating the driveway, position sealer cans lid-down. This enables the solids in the blend to move through the can, making the sealer easier to mix just before application.
- To mix the sealer, use a corded drill with a paddle, like you’d use to mix thinset for tile or joint compound. (Even the thin sealers are relatively thick.) Also have handy a sheet of plywood to create a stable, flat work surface for mixing sealer and stationing tools.
- Think of the prep for sealing your driveway as you might a paint project and get or asphalt as clean and ready to accept the coating as possible.
- While sealing a driveway can be done with hand tools like shovels and push brooms, it’s faster and easier with a few pieces of outdoor power equipment like a string trimmer, blower and pressure washer. It’s also smart to wear old shoes, safety glasses, and a pair of gloves you won’t mind parting with.
- Because you have to finish a complete coat to avoid lap or color issues, purchase one more container than you estimate you’ll need, just in case. It can be saved for touch-ups and is a good insurance policy in case the driveway requires more product than anticipated.
Step 2: Clip the grass
If your lawn isn’t neatly edged where it meets this driveway, clip it using a string trimmer with the head turned so the string spins vertically.
- For grass that has worked its way up through cracks of the driveway, cut it close to the surface with the trimmer.
- Blow away clippings. Yes, two grass items to be dealt with: The grass growing from the lawn ON to the driveway. And grass actually growing up through the driveway
Step 3: Remove grease and dirt
Clean the driveway next. This part of the job calls for a general degreaser, which can be applied with a pressure washer that has a detergent reservoir, though a garden sprayer will work, too.
Step 4: Remove grease stains:
For oil and gas stains that may repel or discolor the sealer, spot clean with a specialized cleanser and a stiff bristle brush.
- Alternatively—or for really tough petroleum stains—spot-apply a stain-blocking primer. Rather than breaking up stains, stain-blocking primers seal stains in.
- Then, rinse the whole driveway with the pressure washer on lower (green tip) pressure. Grass tendrils that have worked their way into the macadam. You’ll want to get the organic matter out of—or below the surface of—those cracks if you can.
Step 4: Deal with cracks and potholes
- With any live debris attended to, move on to larger cracks and potholes. If there are any loose chunks of macadam, pry them out.
- To seal cracks ¼-inch or larger, use a crack sealer. Basically, it’s an asphalt-like caulk that squeezes or pours in. Some crack sealers are self-leveling, and others may need to be screeded.
- Fill any potholes with an asphalt repair mix. Tamp and screed as smooth as the product will allow. An (eminently handy) margin trowel might work well to both scoop and screed the product.
- Blow the driveway off again.
Step 5: Cut in borders
- To use the room-painting example again, cut in the borders of the driveway using a 4-inch throwaway paint brush.
- Work the material into the nooks and crannies.
- For areas where it might be hard to cut in or require extra protection—like paver steps or a garage slab or door—tape them off.
Step 6: Applying Sealant to the Field
- Apply driveway sealant to the field. (Jargon: Anything that’s not the edges, or perimeter, of something—sheet of plywood, tile floor, deck—is called the “field”). Follow product directions to apply, but typically, sealant is poured out right from the bucket. Be careful not to spatter non-driveway surfaces.
- For thicker sealants, scrubbing it in with the brush side of the mop integrates it with the rougher surface of older driveways. While thinner, less viscous, sealers can be applied with the squeegee side.
- Depending on the sealant, one or two coats may be required. In either case, coating the field north-south or east-west is usually recommended.
- As you apply material, once you’re about halfway through a bucket, start to add a new bucket in. This spreads out any color disparity and makes it disappear, yielding a uniform, new-looking surface.
Step 7: Keep Off the Driveway
To keep others from driving on the surface, block the foot of the driveway with cones or used sealant
Best Sealers to Use
The best driveway sealer for you depends on your climate and condition of your driveway. The main three categories of sealer are thick, thin, and quick drying.
When to use thick sealer
If your driveway has lots of cracks, lumps, bumps, potholes, and hasn’t been taken care of in a while (or ever)—and you experience winter weather—thick is probably the best choice.
When to use thin sealer
For less snowy climes and driveways in better condition, thin may deliver the best service. Thin—or lower viscosity—sealers may also be easier to work with as well because they’ll flow more easily than a thicker product.
If you need to get back on the driveway quickly—and have the ability to work speedily—quick-drying formulae may be an option. Walkable in as little as an hour, fast-drying formulae still take an entire 24-hours to cure.
And check individual products for low-temperature warnings if you’re applying in the Spring or Fall.