How to Clean a Driveway Before Sealing? Prep driveway like a Pro

Last Updated on March 24, 2025

Your driveway endures constant exposure to vehicles, foot traffic, harsh weather, oil drips, and dirt. Over time, this takes a toll—leading to cracks, fading, and stains. Sealing can reverse some of that wear and protect the surface from further damage. However, sealing without cleaning is like painting over dust—it won’t last. To get the best results from any sealer, it’s essential to clean driveway before sealing to remove dirt, oil, and stains that can affect adhesion.

A clean surface is essential for the sealer to bond properly with the material (whether it’s asphalt or concrete). Dirt, oil, mold, and old sealer residue can create a barrier that prevents adhesion. This can result in peeling, bubbling, or a blotchy finish that reduces the lifespan of your sealer.

How to Clean Driveway Before Sealing – A Step-by-Step Prep Guide

Let’s now walk through how to get your driveway perfectly clean and ready for sealing.

How to Clean Surfaces on the Same Day

Many homeowners wonder: Can I clean and seal my driveway on the same day? The answer is yes—but with the right approach and materials.

Here are some key considerations if you plan to clean and seal on the same day:

1. Use a Fast-Drying Cleaner

Opt for commercial-grade cleaners designed to break down oil, grease, and dirt quickly. Citrus-based or biodegradable degreasers are great options for environmentally friendly and fast results.

2. Avoid Soaking the Surface

Instead of heavily saturating the driveway with water, use a controlled power washing process that removes grime while minimizing standing water.

3. Use a Surface Dryer or Leaf Blower

Once cleaned, help speed up drying by using a high-powered blower or squeegee to push off excess water. Direct sunlight and warm temperatures also help.

4. Choose a Sealer Designed for Damp Surfaces

Some water-based sealers allow for same-day application, even on slightly damp surfaces. Check the manufacturer’s recommendations—some products are specifically labeled as “damp-surface compatible.”

Important: If the surface feels cool or wet to the touch, wait. Trapped moisture under a sealer can lead to white spots or blistering.

Prepare the Surface

Before deep cleaning with a power washer, start by manually preparing the driveway. This step removes the top layer of loose debris and addresses spot issues that power washing alone might miss.

Steps to Prepare the Surface:

1. Clear Loose Debris
   Sweep the entire driveway using a stiff-bristled broom to remove loose dirt, leaves, sticks, and stones. A clean surface allows power washing to be more effective.

2. Remove Weeds and Grass
   Pull out any weeds growing in cracks or along the edges of the driveway. You can also use a weed killer 24–48 hours before cleaning to ensure they don’t grow back quickly.

3. Trim Overhanging Grass
   If grass or plants are growing over the edges of the driveway, trim them back to expose the full surface.

4. Spot-Treat Stains
   Use a concrete or asphalt-safe degreaser on visible stains. For oil or grease, apply the degreaser, let it sit for 10–15 minutes, then scrub with a wire brush.

5. Address Mold and Mildew
   If your driveway has black, green, or white spots (often mildew or algae), use a bleach solution (1 part bleach to 10 parts water). Apply it with a pump sprayer and let it soak in for 15 minutes before rinsing.

This prep work lays the groundwork for a thorough power wash.

Power Wash

Now it’s time for the heavy-duty cleaning: power washing. This step blasts away embedded grime, mold, stains, and even remnants of old sealant.

How to Power Wash a Driveway:

1. Choose the Right Equipment
   Use a pressure washer with a rating of at least 3000 PSI (pounds per square inch). For larger driveways or tougher grime, a higher PSI (up to 4000) may be needed.

2. Use a Surface Cleaner Attachment
   A surface cleaner helps you wash evenly and reduces streaks. It also covers a wider area, making the job faster.

3. Work in Sections
   Divide your driveway into manageable sections. This ensures every part gets equal attention and helps you monitor your progress.

4. Use Overlapping Strokes
   Always overlap your passes by a few inches to avoid visible lines. Start at the highest point and work downward to allow gravity to help rinse debris away.

5. Focus on Stubborn Areas
   For oil or deeply stained spots, switch to a turbo nozzle for concentrated pressure. You can also reapply cleaner and scrub with a stiff brush if needed.

6. Rinse Thoroughly
   After power washing, go over the driveway with a clean water rinse to remove any detergent residue.

Let It Dry

Unless you’re using a same-day sealer, allow the driveway to dry for at least 24–48 hours. Concrete and asphalt are porous and may hold moisture beneath the surface, especially in cooler weather or shaded areas.

Choose Your Sealant

Before starting the cleaning process, you need to choose your sealant. The type of sealant you use depends on your driveway material and the protection you want.

For asphalt driveways:

• Coal tar sealants: Long-lasting, highly resistant to oil and gas.

• Asphalt emulsion sealers: Eco-friendlier and easier to apply.

For concrete driveways:

• Penetrating sealers: Invisible protection that soaks into the surface.

• Acrylic or epoxy sealers: Add shine and surface protection.

Make sure to read the product label carefully and pick a sealant suited to your climate and driveway condition.

How to Remove Oil Stains Before Sealing Driveway

Oil stains can ruin your sealing job if not removed properly. The sealant won’t stick well to oily patches, resulting in peeling or discoloration.

Here’s how to remove oil stains effectively:

• Absorb fresh spills using cat litter or sawdust. Let it sit for several hours, then sweep away.

• Apply degreaser or dish soap to the stained area and scrub with a stiff-bristled brush.

• Let it soak for 15–30 minutes, then rinse with a hose or pressure washer.

• Repeat if necessary or use a commercial driveway cleaner for stubborn stains.

Always make sure the area is completely clean and dry before applying any sealant.

Cleaning Asphalt Driveway Before Sealing Tips

Proper cleaning is especially important for asphalt surfaces. Follow these essential tips to prepare your driveway:

• Sweep the surface thoroughly to remove leaves, dirt, gravel, and loose debris.

• Power wash to eliminate embedded dirt, algae, or mildew. A clean surface allows the sealant to bond properly.

• Repair cracks and potholes using asphalt filler. Allow enough drying time before sealing.

• Remove weeds from cracks and apply a weed killer if needed.

• Allow the driveway to dry completely—usually 24 to 48 hours—before sealing.

Skipping any of these steps can lead to a failed seal or uneven finish.

Let the Sealant Dry

Once the driveway is clean, dry, and sealed, it’s important to let the sealant dry properly. This final step affects the overall durability and appearance of the seal.

Keep the following in mind:

• Allow at least 24–48 hours of drying time before walking or driving on the surface.

• Check the weather forecast and make sure there’s no rain expected for a full day after sealing.

• Use cones or barriers to block off the area and prevent accidental use.

• In humid or cool weather, the curing process may take longer—sometimes up to 72 hours.

Don’t rush this step. Proper drying ensures your hard work pays off with a long-lasting, smooth, and protective seal.

Conclusion

Cleaning your driveway before sealing is more than just a prep step—it’s the foundation of a successful sealing job. Without proper cleaning, even the best sealant can fail to perform.

To recap:

• Choose your sealant based on driveway type and local conditions.

• Remove oil stains thoroughly before sealing to ensure good adhesion.

• Follow proven cleaning tips for asphalt driveways, including pressure washing and crack repair.

• Let the sealant dry undisturbed for at least 24–48 hours for the best results.

A well-prepared driveway not only looks better but also stays protected longer. Taking the time to clean and prep properly ensures your sealing project lasts for years to come. Always remember to clean driveway before sealing—it’s the most important step to ensure a smooth finish and long-lasting protection.