How to Prepare Your Driveway for Sealcoating: Step-by-Step

Prep Work Makes or Breaks Your Sealcoat

Sealcoating protects your driveway from UV damage, water infiltration, and chemical spills. But a sealcoat is only as good as the surface beneath it. Apply sealcoat over a dirty, cracked, or oil-stained surface and you get poor adhesion, premature peeling, and wasted money.

The good news: proper preparation is straightforward. Most of it takes a few hours of simple labor, and the payoff is a sealcoat that bonds correctly and lasts a full 2-3 years before the next application.

This guide covers exactly what to do before getting your driveway sealcoated, whether you are hiring a contractor or doing it yourself.

Tools and Materials You Will Need

If your contractor handles all prep work (most professional services do), you can skip the tools list. But if you are doing some or all of the prep yourself, gather the following:

• Stiff-bristle push broom
• Pressure washer (1,500-2,500 PSI) or garden hose with high-pressure nozzle
• Weed puller or flat-head screwdriver for crack weeds
• Herbicide or boiling water for weed roots
• Degreaser or trisodium phosphate (TSP) for oil stains
• Asphalt crack filler (cold-pour for cracks under 1/2 inch, hot-pour for wider cracks)
• Caulk gun (if using cold-pour crack filler)
• String trimmer or edging tool
• Leaf blower

Most of these are standard garage items. The only specialty purchase for most homeowners is the crack filler, which runs $8-$15 per tube at any hardware store.

Step 1: Check the Weather Forecast

Before you start any physical prep, check the 5-day forecast. Sealcoating requires:

• Air and surface temperatures above 50 degrees F
• No rain for at least 48 hours after application
• Humidity below 75 percent

In Oregon, the reliable window is late July through mid-September. If rain is in the forecast within 48 hours of your scheduled sealcoating date, postpone. A rained-on sealcoat before it cures is a failed sealcoat. For more on curing conditions, read about how long sealcoating takes to dry.

Plan to complete your prep work 1-2 days before the sealcoating appointment. This gives crack filler time to cure and ensures the surface is fully dry.

Step 2: Remove Vehicles and Clear the Surface

Move all vehicles off the driveway. Remove basketball hoops, planters, trash cans, and anything else sitting on the surface. You need full, unobstructed access to every square foot.

This sounds obvious, but it is the most common source of day-of delays. If your contractor arrives and half the driveway is blocked, the job either gets rescheduled or portions get skipped.

Step 3: Pull Weeds and Vegetation

Weeds growing through cracks are a sign of existing damage, and they will prevent sealcoat from adhering in those areas. Pull all vegetation by hand or with a flat-head screwdriver, getting as much root material as possible.

For persistent weeds, apply a non-selective herbicide 5-7 days before sealcoating, or pour boiling water directly on the root zone. The goal is dead roots that will not push back through the sealcoat.

Trim any grass or ground cover that has crept over the driveway edges. Use a string trimmer or edging tool to create a clean boundary between the asphalt and adjacent landscaping. Grass overlapping the edge traps moisture and prevents the sealcoat from sealing the driveway's most vulnerable zone.

Step 4: Treat Oil and Chemical Stains

Oil-soaked asphalt will not bond with sealcoat. The petroleum in motor oil dissolves the binder in both the asphalt and the sealcoat, creating a soft spot where the coating peels or never adheres at all.

For fresh oil stains (less than a week old):

1. Absorb excess oil with cat litter or sawdust — let it sit for 2-4 hours
2. Sweep up the absorbent material
3. Scrub the area with a commercial degreaser or TSP solution
4. Rinse with a pressure washer

For old, set-in oil stains:

1. Apply a commercial asphalt degreaser and let it soak for 15-30 minutes
2. Scrub with a stiff brush
3. Pressure wash at 2,000+ PSI
4. Repeat if the stain is still visible
5. If the oil has deeply penetrated, the contractor may need to apply an oil-spot primer before sealcoating

Be honest with your contractor about oil stains. A professional will use an oil-spot primer on problem areas to ensure adhesion. Hiding stains under sealcoat guarantees failure in those spots.

Step 5: Clean the Entire Surface

This is the most important prep step. Sealcoat needs to bond directly to clean asphalt. Any dirt, dust, sand, or debris between the surface and the sealcoat creates a weak layer where the coating will eventually peel.

The best approach: pressure washing. A pressure washer at 1,500-2,500 PSI removes embedded dirt, moss, and surface contaminants that a broom cannot reach. Work in overlapping passes across the entire driveway, paying extra attention to shaded areas where moss and algae accumulate (common in Oregon).

If you do not have a pressure washer: Sweep the entire surface with a stiff push broom, then follow up with a garden hose and high-pressure nozzle. This is acceptable but not as thorough. Let the driveway dry completely after washing, which typically takes 24-48 hours in Oregon's summer conditions.

A leaf blower is useful for a final pass to remove any remaining dust or debris after the surface has dried.

Step 6: Fill Cracks

Every crack wider than 1/8 inch should be filled before sealcoating. Sealcoat is 1/16 to 1/8 inch thick — it cannot bridge gaps wider than that. Unfilled cracks allow water infiltration directly beneath the sealcoat, undermining the entire purpose of the application.

For cracks 1/8 to 1/2 inch wide:

• Use cold-pour crack filler applied with a caulk gun
• Fill to slightly below the surface level (the filler will settle)
• Allow 24-48 hours to cure before sealcoating

For cracks wider than 1/2 inch:

• Use hot-pour crack filler or backer rod with cold-pour filler
• These may require a professional application
• Allow 48 hours minimum to cure

For alligator cracking (interconnected pattern of small cracks):

• This indicates structural failure beneath the surface
• Sealcoating over alligator cracking is a waste of money
• The area needs patching or replacement before any sealcoat is applied

If you are hiring a contractor, ask whether crack filling is included in the sealcoating price. Many Oregon contractors include cracks up to 1/4 inch as part of the standard service, with wider cracks available as an add-on.

Step 7: Edge the Driveway Borders

The edges of your driveway are the first places sealcoat fails. Grass, soil, and gravel encroaching on the asphalt edge prevent proper coverage and trap moisture.

Use an edging tool or flat shovel to create a clean 1-2 inch gap between the asphalt edge and any adjacent material. This allows the contractor to sealcoat all the way to the edge, which is where water infiltration typically starts.

Step 8: Protect Adjacent Surfaces

If you are doing any prep that involves chemicals (degreaser, herbicide), protect adjacent concrete, pavers, and landscaping. Sealcoat itself will stain concrete and pavers permanently, but that protection is usually the contractor's responsibility on application day.

Your responsibility: make sure sprinklers are turned off for 48 hours before and after sealcoating. An unexpected sprinkler cycle can ruin a fresh sealcoat.

What the Contractor Handles vs. What You Handle

Most professional sealcoating services include some level of prep, but the scope varies. Here is a typical breakdown:

Contractor handles:

• Final surface cleaning (blowing or light power washing)
• Masking garage doors, walkways, and landscaping edges
• Filling hairline to 1/4 inch cracks (often included)
• Applying oil-spot primer where needed
• Barricading the driveway during curing

Homeowner handles (or should handle in advance):

• Moving vehicles, planters, and obstacles
• Pulling weeds from cracks
• Treating heavy oil stains
• Turning off sprinklers
• Informing the contractor of known problem areas

When you book your sealcoating, ask your contractor exactly what their service includes. At Cojo, our standard sealcoating service includes surface prep, crack filling up to 1/4 inch, and full cleanup. We will walk the driveway with you before we start and flag anything that needs attention.

Prep Timeline: 3 Days Before Sealcoating Day

This schedule gives each step adequate curing and drying time. Rushing the prep, especially crack filling and surface drying, compromises the result.

When Prep Is Not Enough

Sometimes, during prep, you discover damage that sealcoating cannot address. If you find:

• Cracks wider than 1 inch — these need professional patching
• Potholes or depressions — these need filling with hot mix asphalt
• Large areas of alligator cracking — the sub-base may need repair
• Standing water that does not drain — a drainage issue needs correction first

Sealcoating over structural damage is money wasted. A good contractor will tell you this upfront. If your driveway needs repairs before sealing, it is better to invest in fixing the problems first and sealcoating second.

Choosing DIY vs. professional sealcoating is another factor — but either way, the prep is the same.

Schedule Your Sealcoating

Proper prep turns a good sealcoat into a great one. If your driveway is due for sealcoating this season, start your prep early and schedule your appointment before Oregon's summer season fills up.

Cojo provides professional sealcoating services with thorough prep and commercial-grade products. Contact us to schedule your sealcoating or to get a free driveway assessment.