What Is Driveway Seal Coating?
Driveway seal coating is the process of applying a protective coating over an existing asphalt driveway. The coating is generally made from a bituminous material combined with water, mineral fillers, additives, or other ingredients depending on the product. It creates a protective surface over the asphalt rather than replacing the pavement underneath.
Seal coating is primarily used on asphalt surfaces that are structurally sound but need protection from normal weathering and surface deterioration.
Important: seal coating is maintenance, not a replacement for damaged asphalt. Large potholes, major cracks, severe drainage problems, and structural pavement failures should generally be repaired before applying a seal coat.
Why Seal an Asphalt Driveway?
1. Protects Against Water
Water is one of the biggest threats to asphalt pavement. When it enters cracks and damaged areas, it contributes to deterioration of the pavement structure. A properly applied seal coat helps reduce direct exposure to moisture.
2. Reduces UV Damage
Sunlight gradually oxidizes asphalt, making it lighter, harder, and more brittle over time. Seal coating provides a protective layer that reduces direct UV exposure.
3. Improves Appearance
Freshly seal-coated asphalt has a darker, more uniform appearance, which can make an older driveway look cleaner and better maintained.
4. Helps Protect Against Chemicals
Automotive fluids such as oil and gasoline can damage asphalt. A suitable seal coat provides additional surface protection, though spills should still be cleaned promptly.
5. Can Help Extend Pavement Service Life
Regular maintenance can slow the deterioration of an asphalt driveway. Seal coating should be considered one part of an overall pavement maintenance program rather than a solution for every asphalt problem.
How to Seal a Driveway
If you're planning a DIY project, proper preparation is just as important as applying the sealant. Here's the basic process, step by step.
Inspect the Asphalt
Look for cracks, potholes, loose asphalt, oil stains, drainage problems, sinking areas, and major surface deterioration. Seal coat should generally be applied to asphalt that's still structurally sound — applying it over extensive structural damage only hides the problem temporarily.
Clean the Driveway
Remove dirt, leaves, grass, stones, loose debris, oil, and grease. A broom handles loose debris; a pressure washer helps with heavier dirt. Allow the driveway to dry thoroughly afterward.
Repair Cracks and Potholes
Small cracks can often be treated with an appropriate asphalt crack filler; larger cracks or potholes may need more extensive repair. Seal coat is a protective coating, not a structural repair material — don't assume it will fill significant cracks.
Remove Oil and Grease
Oil contamination interferes with adhesion. Treat oil spots with an appropriate asphalt-safe cleaning product per the manufacturer's instructions. Heavily contaminated areas may need additional preparation.
Check the Weather
Check the sealant manufacturer's requirements for temperature, rain, humidity, and drying time before starting. Avoid applying sealant immediately before rain or when temperatures fall outside the product's recommended range.
Apply the Seal Coat
Once the surface is clean, dry, and repaired, apply the seal coat per the manufacturer's instructions — by squeegee, brush, spray system, or other suitable equipment. Apply evenly and avoid excessively thick areas.
Allow the Driveway to Cure
Keep vehicles and foot traffic off the freshly sealed surface for the period recommended by the manufacturer. A surface that looks dry may not be fully cured.
How Often Should You Seal a Driveway?
A common maintenance interval is approximately every 2 to 3 years, but there is no universal schedule that applies to every driveway. The ideal interval depends on:
- Climate, sun exposure, rain and moisture
- Traffic volume and vehicle weight
- Existing pavement condition
- Quality of the previous application and surface preparation
- Type of sealant used
Instead of automatically sealing every year, inspect the pavement regularly and follow the recommendations for the specific sealant you use.
Can You Seal a Driveway Too Often?
Yes. Applying seal coat too frequently can result in excessive buildup without additional benefit. The asphalt should have adequate time between applications, and the surface should be evaluated before another coating is applied.
When Should You Reseal an Asphalt Driveway?
Look for signs that the existing protective coating is wearing away:
- The surface has become noticeably faded or gray
- The previous seal coat is wearing unevenly
- Minor surface deterioration is becoming more noticeable
- The driveway has lost much of its previous protective coating
Resealing should not be used to cover serious pavement failures. If the asphalt has widespread potholes, severe cracking, or major settlement, repair or resurfacing may be more appropriate.
Best Time of Year to Seal an Asphalt Driveway
The best time to seal depends on local weather conditions and the requirements of the product being used. Generally, seal coating works best during periods of suitable temperatures with sufficient time to dry and cure. Avoid applying sealant when:
- Rain is expected or the surface is wet
- Temperatures are below the manufacturer's recommended range
- Extremely hot conditions could interfere with application
- Heavy traffic will occur before curing is complete
How Much Sealcoat Do You Need?
The amount of sealant required depends primarily on the driveway's surface area and the product's coverage rate.
Driveway Area = Length × Width
Sealcoat Quantity = Driveway Area ÷ Coverage Rate
For example, if a driveway has an area of 2,000 square feet and a product covers 100 square feet per gallon: 2,000 ÷ 100 = 20 gallons. The actual quantity required may differ depending on the product, surface texture, application method, and number of coats. For an irregularly shaped driveway, divide the surface into smaller sections and add their areas together.
Use the Seal Coat Calculator
Enter your driveway dimensions and coverage rate to estimate the sealant quantity and cost.
Seal Coating vs. Asphalt Resurfacing
| Seal Coating | Asphalt Resurfacing |
|---|---|
| Protective maintenance treatment | New asphalt layer over existing pavement |
| Relatively thin coating | Much thicker pavement layer |
| Used on generally sound asphalt | Used when the surface needs more substantial rehabilitation |
| Helps protect the existing surface | Provides a new riding surface |
| Does not correct structural failures | Can address more significant surface deterioration |
If the existing driveway is structurally sound, seal coating may be an appropriate maintenance option. If the pavement has widespread deterioration, resurfacing or reconstruction may need to be considered.
Common Driveway Seal Coating Mistakes
Applying Sealant to Dirty Asphalt
Dirt, dust, oil, and loose debris interfere with adhesion. Always clean and prepare the surface properly.
Ignoring Cracks
Seal coating does not replace crack repair. Repair appropriate cracks before applying the coating.
Applying Too Much Product
A thicker layer isn't automatically better. Follow the manufacturer's recommended application rate.
Sealing Wet Asphalt
Moisture interferes with adhesion and curing. Make sure the pavement is sufficiently dry before application.
Ignoring the Weather Forecast
Unexpected rain can ruin a fresh application. Check the forecast before starting.
Allowing Traffic Too Early
A surface that looks dry may not have fully cured. Follow the manufacturer's traffic restrictions.
Applying Seal Coat to Severely Damaged Asphalt
Seal coating cannot fix major structural problems. If the driveway is badly deteriorated, evaluate whether repair, resurfacing, or reconstruction is necessary first.
How Long Does Driveway Seal Coating Last?
A commonly used maintenance interval is around 2 to 3 years, but the actual life of the coating depends on the environment, traffic, preparation, application quality, and product used. A driveway exposed to intense sunlight, heavy traffic, frequent rain, or harsh winter conditions may need maintenance sooner than a lightly used driveway in a moderate environment. The best approach is to inspect the pavement periodically rather than relying only on a fixed calendar schedule.
Does Seal Coating Fill Cracks?
Generally, no. Seal coating is designed primarily to protect and seal the asphalt surface — it should not be treated as a replacement for a proper crack-filling material. Small cracks should be evaluated and repaired with a suitable product before seal coating. Larger cracks and structural failures may require more extensive pavement repair.
Can You Seal a New Asphalt Driveway?
New asphalt generally needs time to cure before seal coating. The exact waiting period depends on the asphalt mix, weather, traffic, and the recommendations of the asphalt contractor and sealant manufacturer. Do not automatically seal newly installed asphalt immediately — follow the recommendations provided for the specific pavement and sealant.
DIY vs. Professional Driveway Seal Coating
DIY may make sense when:
- The driveway is relatively small
- The asphalt is structurally sound
- You have time for proper preparation
- You can follow product instructions carefully
- You have appropriate application equipment
Professional service may be preferable when:
- The driveway is large
- Extensive repairs are required
- The pavement has significant cracking
- There are drainage or structural problems
- You want a commercial-grade application
The most important part of either approach is proper surface preparation.
Final Thoughts
Seal coating a driveway can be an effective way to maintain an asphalt surface when the pavement is still structurally sound. Proper preparation, suitable weather conditions, correct application, and regular inspection are all important for good results. Before starting your project, inspect the driveway, repair cracks and potholes, clean the surface thoroughly, check the weather, and follow the sealant manufacturer's instructions.
Frequently Asked Questions
A common interval is approximately every 2 to 3 years, but the correct timing depends on the condition of the asphalt, climate, traffic, previous coating, and product used.
Many driveways may benefit from resealing every few years rather than annually. Inspect the surface and follow the sealant manufacturer's recommendations.
The required curing time depends on the specific product and weather conditions. Follow the manufacturer's instructions rather than relying on a universal time.
Seal coating can protect the surface, but it does not eliminate significant cracks. Cracks should generally be repaired separately before sealing.
It may be possible when the existing coating is in suitable condition, but the surface must be properly cleaned and prepared. Follow the product manufacturer's instructions.
For structurally sound asphalt, regular sealing can be a useful maintenance measure that helps protect the surface from weathering and moisture while improving its appearance. However, sealing is not a substitute for repairing major pavement damage.
An unsealed asphalt driveway can gradually oxidize and weather. Over time, exposure to water, sunlight, traffic, and other environmental factors can contribute to surface deterioration.
Related Asphalt Tools
Seal Coat Calculator
Estimate the amount of sealant required for your driveway.
Asphalt Tonnage Calculator
Estimate the amount of asphalt material required for a project.
Asphalt Cost Calculator
Estimate the potential material cost of an asphalt project.
Asphalt Density Calculator
Calculate asphalt density and related material quantities.
Bitumen Density Calculator
Calculate the density and weight relationship of bitumen.
Asphalt Removal Calculator
Estimate material quantities for asphalt removal projects.