Driveway Sealcoating Guide

Proper preparation determines 90% of sealcoating results. Start by cleaning the driveway thoroughly. Use a pressure washer (2,000–3,000 PSI) to remove dirt, oil, and loose sealant. For oil stains (which prevent sealant adhesion), apply a degreaser and scrub with a stiff brush, then rinse. Remove all weeds growing through cracks and kill any moss or algae. Allow the driveway to dry completely—48 hours of dry weather minimum. Fill all cracks wider than 1/8 inch with crack filler. Use a caulk-style applicator for narrow cracks and a trowel-grade filler for wider ones. Clean out edges of cracks with a wire brush before filling. Trim any grass growing along the driveway edges—sealant will not stick to wet grass.

Crack filling is the most important preparation step. For hairline cracks (under 1/8 inch), sealcoat will bridge them. For cracks 1/8 to ½ inch, use pourable cold-applied crack filler. For wider cracks (over ½ inch), use a sanded filler or fill with sand first, then seal. For alligator cracking (a network of interconnected cracks), remove the loose pieces, treat with a primer, and apply a fabric overlay before sealcoating. Clean debris from each crack with compressed air or a wire brush. Fill slightly above the surface—the filler will settle and shrink as it cures. Let crack filler dry completely (per manufacturer instructions, usually 4–24 hours) before sealcoating. Properly filled cracks prevent water from penetrating the asphalt base.

Mix the sealcoat thoroughly with a drill mixer attachment. For driveways under 400 square feet, apply with a squeegee and back-brush. For larger areas, use a sealcoating sprayer (rental available). Start at the top of the driveway and work toward the street—do not paint yourself into a corner. Pour a ribbon of sealant across the driveway width, then spread evenly with the squeegee. Apply in thin coats—a single thick coat cracks and peels. Two thin coats applied 4–6 hours apart last significantly longer than one thick coat. Maintain a wet edge to avoid lap marks. For edges, use a brush to apply sealant precisely against the curb or grass. Cover evenly without puddling.

After application, keep traffic off the driveway. Set up barriers or cones at the driveway entrance. Post a sign or flag to warn household members and delivery drivers. The surface is dry to touch in 4–6 hours but not cured enough for traffic. Wait 24–48 hours before driving on the driveway. For the first 30 days (full cure), park in different spots to avoid tire marks. Do not use a pressure washer on the sealed surface for at least 60 days. Do not apply any other coatings or cleaners for 90 days. If rain threatens within 24 hours of application, do not start. Rain on fresh sealcoat ruins the finish and requires reapplication.

DIY sealcoating costs $40–$100 (materials only) for a standard two-car driveway (400–600 sq ft). Professional sealcoating costs $200–$500. DIY saves money but requires effort, proper weather timing, and disposal of leftover materials. Professionals have spray equipment that applies coating more evenly, use higher-grade commercial sealants, and often include crack filling. Professional results last 3–4 years vs. 2–3 years for DIY. For driveways over 800 sq ft or those with significant cracking, professional application is worth the cost. For simple, small driveways in good condition, a careful DIY job produces satisfactory results. Whichever route you choose, proper preparation determines success.