How to Seal a Driveway and Fix Cracks

Sealing and repairing cracks in your driveway is an important maintenance task that helps protect the surface from damage and extends its lifespan. A properly sealed driveway looks nicer, lasts longer, and increases curb appeal. This comprehensive guide provides tips on selecting the right sealant products, preparing the surface, applying the sealer, and fixing common cracks and problems.

Why Seal Your Driveway?

Sealing your asphalt or concrete driveway every 2-3 years is highly recommended to prevent deterioration and damage. Here are some of the top benefits of sealing your driveway:

  • Prevents Water Damage – Sealer forms a protective barrier that prevents water from seeping into cracks and pores in the driveway. This water protection reduces freeze-thaw damage, cracking, potholes, and other problems.
  • Protects Against UV Rays – The sun’s harsh UV rays can cause asphalt driveways to oxidize, fade, and become brittle over time. A protective sealer layer blocks UV radiation.
  • Resists Gas & Oil Stains – Oil leaks and drips from cars can stain and damage driveway surfaces. Sealing helps make the driveway more resistant to oil and grease stains.
  • Reduces Ice Buildup – Sealed driveways are less porous, so ice has a harder time forming a bond with the surface. This makes de-icing easier in winter.
  • Improves Appearance – A fresh seal gives worn, faded asphalt or concrete a new look. It restores the dark black color and provides a like-new appearance.
  • Potentially Adds Value – An old, cracked, stained driveway hurts curb appeal. Sealing and repairing it can add value when it comes time to sell the home.

What Type of Driveway Sealer is Best?

When selecting a driveway sealer, look for products specifically formulated for the surface material:

Asphalt Driveway Sealers

  • Coal Tar Sealers – Made from coal tar pitch emulsion, this thick black sealer is designed to waterproof and extend asphalt driveway lifespan. Coal tar has a long track record, but the odor may be unpleasant.
  • Asphalt Emulsion Sealers – These are water-based and made from asphalt cement, water, emulsifiers, and fillers. They have less odor than coal tar and are easier to apply.
  • Acrylic Sealers – Acrylic latex sealers form a clear, protective coating on asphalt driveways. They resist gas and oil staining but need reapplying more frequently.

Concrete Driveway Sealers

  • Acrylics – Acrylic latex sealers work well for protecting decorative concrete driveways. They resist salt, chemicals, and UV rays while allowing vapor transmission.
  • Epoxies – Two-part epoxy sealers provide a high-gloss, durable coating for concrete. They seal better than acrylics but may turn yellowish over time.
  • Polyurethanes – Polyurethane concrete sealers provide a clear, non-yellowing finish. They offer excellent resistance to abrasion, chemicals, and salt damage.
  • Polyaspartics – Polyaspartic sealers offer durability similar to epoxies with faster drying times. However, they have a limited pot life after mixing.

How to Prepare a Driveway for Sealing

Proper prep work is crucial for achieving good sealer adhesion and performance. Here are tips on getting your driveway ready for a new coat of sealer:

  • Clean Thoroughly – Use a pressure washer or scrub with a degreaser to remove built-up dirt, grime, oil drips/stains, and other contaminants. Rinse thoroughly after cleaning.
  • Repair Cracks – Fill any cracks wider than 1⁄4 inch with a sealant or caulk before sealing. This helps prevent moisture intrusion and further cracking.
  • Check Drainage – Ensure water drains away from the driveway and there are no low spots or depressions where water can pool.
  • Remove Debris – Sweep or blow away any leaves, branches or other debris from the driveway surface before sealing.
  • Mask Off Areas – Use painter’s tape to mask off adjacent surfaces you don’t want coated, like the foundation wall. Remove tape within 24 hours of sealing.
  • Check Weather Forecast – Pick a dry day with no rain expected for 24-48 hours. Avoid sealing in very hot midday sun or if temperatures are below 50°F.
  • Allow Proper Cure Time – Freshly paved driveways need about 6 months to cure before sealing. For concrete, wait at least 30 days.

How to Apply Driveway Sealer

Follow these key steps to seal your asphalt or concrete driveway like a pro:

1. Stir or Shake Sealer Well

Before pouring sealer into the sprayer or squeegee tray, thoroughly mix the sealer with a stick to disperse solids settled at the bottom. This ensures even application.

2. Use a High-Quality Applicator

Options like an asphalt sealcoating machine, squeegee system, or spray equipment from a reputable company will make the job much easier. Read equipment instructions.

3. Add Thin Coats in Sections

Work in sections of around 300 sq ft starting at the highest elevation. Pour a bead of sealer and spread it across with the squeegee. Apply 2-3 thin coats rather than 1 thick coat, allowing proper drying between coats.

4. Backroll with a Sealer Roller

Once spread, go over the entire section with a long nap roller to smooth out the sealer and even out the coat. Distribute any puddles.

5. Blend New and Old Sealer

Overlap sections to blend the new and existing sealer. Try to maintain a wet edge as you work. Feather out margins where sealer ends.

6. Allow Proper Cure Time

Let the sealer dry for the recommended time before allowing foot traffic or parking. This may range from 8-24 hours. Add caution cones or barricades while curing.

7. Apply Beads Along Edges

Once cured, apply a bead of sealer along the edges with a paintbrush to coat porous areas that dried faster. This provides added protection.

How to Fix Cracks in a Driveway

Cracks are common in aging, damaged driveways. Here are tips on repairing different types of cracks:

Hairline & Small Cracks

For cracks less than 1⁄4 inch wide, a sealer or caulk is often adequate for filling. Rout wider cracks before filling so the repair material has something to bind to.

  • Sweep out loose debris from the crack with a wire brush.
  • Apply a concrete or asphalt crack filler/sealant per the manufacturer’s directions.
  • Use a caulk gun, putty knife, or trowel to fully pack the crack with sealant.
  • Tool the sealant smooth with the edge of a putty knife. Allow proper curing time before sealing over it.

Large Cracks

Larger cracks over 1⁄4 inch wide require patching before sealing to prevent continued spreading.

  • Use a chisel or circular saw with a concrete/asphalt blade to open up the crack wider and cut a rectangular shape.
  • Clean out debris and vacuum up dust.
  • Fill the crack with a concrete or asphalt patch mix, tamping it down firmly.
  • Smooth and level it off flush with the surrounding surface. Allow curing before sealing.

Potholes

For holes and depressions, clean out the area and fill with a concrete or asphalt patch mix. Tamp it down into layers until it’s level with the driveway. Allow adequate curing time before sealing, usually about one week.

Expansion Joint Damage

Seal damaged expansion joints with a polyurethane joint sealant. Rout out old sealant, clean thoroughly, and apply new sealant with a caulk gun. Tool to shape.

Preventing Weed Growth

To prevent weeds sprouting in cracks, apply a liquid herbicide spray or borax powder before sealing. This will kill roots and seeds so weeds can’t penetrate the sealed surface.

FAQs About Driveway Sealing and Crack Repairs

Does a brand new driveway need sealing right away?

Wait at least 6 months before sealing a new asphalt driveway and 30 days for concrete to allow proper curing. Sealing too early can lead to bonding issues.

What is the best time of year to seal a driveway?

Late summer or early fall is ideal when temperatures are still warm but the hot summer sun has passed. Avoid sealing in winter or when rain is expected within 24-48 hours.

How long does driveway sealer last?

On average, driveway sealcoat lasts 2-3 years before needing reapplication. Durability depends on traffic, weathering, and the quality of preparation and application.

How long does it take for driveway sealer to fully cure?

Cure times vary by product, but expect 8-24 hours before driving or parking on the sealed surface. Add barricades and warning signs while curing and before the coating is hard.

What is the white powder that appears on my driveway after sealing?

White residue after sealing typically means the product was not mixed thoroughly before application. The powder is dried sealer components that settled out.

Can you seal over existing driveway sealer?

Yes, as long as the old sealer is in good condition without extensive flaking or peeling. Clean thoroughly and ensure proper adhesion. Multiple thin coats are better than one thick coat.

Why do tire marks keep appearing on my sealed driveway?

This usually occurs because the sealcoat was not allowed to fully cure before vehicles were parked. Give the sealer at least 24 hours to harden before driving on it.

How long after sealing before parking a vehicle or adding deck furniture?

It’s best to wait at least 24-48 hours before parking vehicles on a freshly sealed driveway. For furniture, wait about 5 sunny days to ensure the sealer has fully cured and bonded.

Conclusion

Sealing and repairing a deteriorating driveway is a project any homeowner can tackle. With the right materials and preparation, the process helps protect the surface and extends the life of aging asphalt or concrete. Be sure to allow proper curing time based on the product directions before allowing vehicles back onto the driveway or patio furniture onto the surface. Consistent sealing every few years will maintain the driveway’s appearance and prevent costly damage from occurring. Your properly maintained and expertly sealed driveway will boost curb appeal while standing up to years of vehicle and weather exposure.


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