Asphalt makes an excellent driveway surfacing material but it does require annual maintenance and upkeep. Inevitably, small cracks and holes will appear in the asphalt surface. Left untended, these defects will allow water to enter in the asphalt surface and penetrate to the substrate, causing a softening. When heavy vehicles travel over the surface, they push the asphalt down into the soft substrate, causing cracks and holes to develop. Cycles of freezing and thawing will eventually heave the asphalt and require major repairs. Ultraviolet rays from the sun and oxidation also play a role in asphalt deterioration. This damage can be avoided by an annual application of a sealcoat. Asphalt sealcoating can be found at most builder supply stores and home centers. It is best to not sealcoat a new asphalt installation as the sealcoat will prevent the surface oils in the new asphalt from evaporating, causing the new asphalt to remain soft.
- Wait to apply a sealcoat to your asphalt driveway until you have at least two days of warm, dry weather.
- Sweep your driveway or asphalt surface.
- Using an asphalt repair compound, fill all the large cracks and holes larger than 1/4″ in the asphalt surface.
- Allow these repairs to dry well.
- Asphalt sealcoat will fill and seal smaller defects in the surface.
- Spray down the asphalt surface thoroughly to remove dust and any lingering debris.
- Wait for the surface to dry before applying the sealcoat material.
- The components of the sealcoat material may have separated over time so it is best to tip the container over and let it set for a short period before stirring and use. This will allow the ingredients to settle throughout the sealcoating, making a more uniform mixture.
- Stir the sealcoat mixture thoroughly.
- Pour an amount of the mixture in one corner of your asphalt surface and spread it smoothly. You can use a paint roller, a sprayer with a tip designed for heavy viscosity fluids, or a toothed squeegee. The idea is to achieve a uniformly smooth, thin surface application.
- Do not try to apply the seal coat to too large an area at one time.
- After applying the sealcoat to the entire asphalt area, allow it to dry thoroughly for at least two days before allowing vehicles or people on it.
Make sure all oil spills are thoroughly cleaned and removed. Use a commercial quality detergent and a scrub brush or wire brush to get as much oil up as possible.
Some sealcoat materials are better than others. As always, price is a good guideline. The more the sealcoat material costs, the better quality the ingredients.
Some coal tar sealcoat applications are reputedly messy and very difficult to apply successfully.
Block off the entrance to your driveway or sidewalk with sawhorses or barricades and caution tape to prevent people and vehicles from treading on your new sealcoat application.
Remember that a new sealcoat application over asphalt renders the surface slippery. You can provide a degree of traction to prevent accidents by adding fine sand to your sealcoat mix. Stir it in with a mixer paddle and drill motor.
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