Asphalt Sealer Calculator
Sealcoating extends the life of your asphalt. Calculate exactly how many gallons and 5-gallon buckets you need to buy.
Pro Tip: Buy 1 extra bucket. Running out of sealer in the middle of a driveway leaves an ugly seam.
Comprehensive Guide to Asphalt Sealcoating
Protecting your asphalt driveway or parking lot through sealcoating is one of the most cost-effective maintenance tasks you can perform. It acts as a barrier against water, oils, and UV rays, preventing the asphalt from oxidizing and crumbling over time. Whether you're a DIY enthusiast or preparing to hire a contractor, understanding the materials, methods, and costs associated with sealcoating is essential for a successful project.
Sealcoating Coverage Rate by Method
The amount of sealer you need depends heavily on how you apply it. Different application methods yield different coverage rates, affecting both the thickness of the protective layer and the total cost. Here is a quick reference table for coverage rates based on the application method.
| Application Method | Coverage Rate (sq ft / gallon) | Best Used For |
|---|---|---|
| Spray | 90 - 110 | Large commercial lots, smooth surfaces, fast application |
| Squeegee | 55 - 65 | Forcing sealer into porous, older asphalt, thick coats |
| Brush | 45 - 55 | Edging, extremely rough surfaces, DIY applications |
Note: Your asphalt's condition significantly affects these rates. Highly oxidized (rough, gray) asphalt will absorb more material, lowering your coverage rate. New or previously sealed asphalt will yield higher coverage.
How Much Does Sealcoating Cost?
The cost of sealcoating can be broken down into DIY material costs versus professional application costs. If you choose the DIY route, a typical 5-gallon bucket of asphalt sealer costs between $30 and $50. At an average coverage rate of 300 square feet per bucket (using a squeegee), a standard 600-square-foot driveway would require two to three buckets per coat, totaling approximately $60 to $150 in sealer alone. You'll also need to budget for application tools, crack filler, and cleaning supplies (push brooms, degreasers).
If you hire a professional, the cost typically ranges from $0.15 to $0.25 per square foot. For the same 600-square-foot driveway, you can expect to pay a contractor between $90 and $150. Given the minimal price difference between DIY and professional application, many homeowners opt to hire out this messy, labor-intensive task. However, doing it yourself ensures you can apply a thicker coat and pay meticulous attention to detail.
Sealer Type Comparison
Not all sealers are created equal. The type of sealer you choose will dictate its longevity, environmental impact, and appearance.
| Sealer Type | Pros | Cons |
|---|---|---|
| Coal Tar | Highly durable, fuel/oil resistant, lasts 3-5 years | Strong odor, skin irritant, banned in many municipalities due to PAHs |
| Asphalt-Based Emulsion | Eco-friendly, low odor, safe to handle, deep black color | Less resistant to gas and oil spills, lasts 2-3 years |
| Acrylic | Environmentally safe, UV resistant, available in colors, long-lasting | Most expensive option, requires precise application |
When to Sealcoat Your Driveway
Timing is critical when it comes to sealcoating. You should not sealcoat a brand-new asphalt driveway immediately. New asphalt contains oils that need to evaporate (cure) over time. You should wait at least 6 to 12 months before applying the first sealcoat. After the initial application, a good rule of thumb is to reseal every 2 to 3 years.
Temperature and weather also play a massive role. Sealcoat should only be applied when the ambient and pavement temperatures are at least 50°F and rising, with no rain forecasted for at least 48 hours. Applying sealer in direct, scorching sunlight can cause it to dry too quickly, leading to peeling and flaking.
Step-by-Step Sealcoating Guide
If you have decided to tackle the sealcoating project yourself, follow these steps to ensure a professional-quality finish:
- Clean the Surface: Use a stiff push broom and a leaf blower to remove all dirt, leaves, and debris. If you have oil stains, treat them with a degreaser and scrub vigorously. Oil spots will prevent the sealer from adhering.
- Fill the Cracks: Sealer is not meant to fill cracks. Use a specialized rubberized crack filler for any cracks wider than 1/8 inch. Allow the crack filler to cure completely according to the manufacturer's instructions.
- Trim the Edges: Use an edger or string trimmer to cut back grass and weeds along the sides of the driveway. Tape off any concrete sidewalks or garage aprons to prevent accidental staining.
- Mix the Sealer: Sealer settles over time. Turn the 5-gallon buckets upside down the night before your project. Right before application, open the buckets and stir thoroughly with a mixing paddle until the consistency is uniform.
- Cut In the Edges: Use a large driveway brush to "cut in" the perimeter of the driveway. This gives you a safe border so you won't accidentally slop sealer onto your grass or nearby concrete when using the squeegee.
- Apply the Main Area: Pour a ribbon of sealer across the driveway. Using a heavy-duty driveway squeegee, pull the sealer down the driveway, maintaining a wet edge. Apply firm downward pressure to force the sealer into the pores of the asphalt.
- Cure and Second Coat: Allow the first coat to dry completely (usually 4 to 8 hours depending on humidity). If you are applying a second coat, apply it perpendicular to the first coat to ensure maximum coverage and fill in any missed pores. Keep all traffic off the driveway for 24 to 48 hours.
Frequently Asked Questions
How long does it take for asphalt sealer to dry?
Sealer will typically be dry to the touch in 2 to 4 hours under ideal conditions (sunny, warm, and low humidity). However, "dry to the touch" does not mean cured. You should wait at least 24 to 48 hours before driving any vehicles on the newly sealed surface to prevent tire tracking and scuffing.
Do I really need two coats of sealer?
While one coat is often sufficient for routine maintenance on an asphalt surface in good condition, two coats are highly recommended for older, porous asphalt or driveways that haven't been sealed in many years. The first coat acts as a primer, filling the pores, while the second coat provides the actual protective wear layer.
Can I sealcoat over cracks?
No. Asphalt sealer is too thin to bridge cracks effectively. Any cracks larger than a hairline (1/8 inch) must be filled with a dedicated hot or cold-pour rubberized asphalt crack filler before sealcoating. If you just seal over them, the cracks will reappear within weeks.
What happens if it rains after I sealcoat?
If it rains before the sealer has had time to set up (usually within the first few hours), the rain can wash the sealer away, causing streaks and requiring a complete reapplication. Always check the forecast and ensure a clear 48-hour window before starting your project.
Why did my sealer peel or flake off?
Peeling or flaking is almost always caused by poor surface preparation. If the asphalt was dirty, wet, or had existing oil stains, the sealer cannot properly bond. Another common cause is applying sealer when temperatures are too cold or when the sun is too hot, causing flash-drying.
Should I use a squeegee or a brush?
A squeegee is generally best for forcing sealer down into the pores of older, rough asphalt and yields a very thick, protective layer. A brush is excellent for working the sealer into heavily textured areas and cutting in edges. Many professionals use a squeegee for the first coat to fill voids, and a spray or light brush for a smooth finish coat.