One way to extend an asphalt driveway’s life span and to improve the appearance of lusterless, washed-out blacktop is to seal coat it (apply an asphalt-based sealant). As moisture penetrates cracks, then freezes and thaws, cracks grow and allow more water in.
The problem grows. At the same time, sunlight fades and dries the asphalt, making it brittle. Seal coating a driveway is like painting or staining siding—it helps block damaging sunlight and seals-out moisture.
It also helps a driveway to repel gasoline and oil, which disintegrate the asphalt. One gallon covers about 80 square feet, but be sure to check the actual coverage listed on the can.
1) Pull any weeds and sweep the surface.
2) Use a cold-mix asphalt patch to fill holes or wide cracks, and remove stains, as discussed above.
3) Sweep again, then hose off the surface.
4) On a fairly warm day, apply the sealer according to label directions. Normally, you do this while the driveway is still wet. Allow the sealer to cure and avoid using the driveway for 24 hours.