Pressure washing asphalt requires careful consideration to avoid damaging the surface. This comprehensive guide will provide you with the best techniques and technical specifications for cleaning asphalt with a pressure washer, ensuring your driveway or parking lot looks its best without compromising its integrity.
Techniques for Cleaning Asphalt with a Pressure Washer
Preparation
- Clear the area of any furniture, planters, or debris to ensure a thorough and unobstructed cleaning.
- Dry sweep the surface using a push broom or leaf blower to remove loose dirt and debris. This step is crucial to prevent the pressure washer from simply pushing the dirt around rather than effectively removing it.
- Use absorbent materials like kitty litter or asphalt-appropriate degreasers to tackle oil and other stubborn stains. This pre-treatment can significantly improve the cleaning results.
Low Pressure Settings
- Adjust your pressure washer to the lowest pressure setting that still effectively cleans the dirt and grime from the asphalt. High-pressure settings can cause damage or worsen existing problems, such as cracks or potholes.
- Aim for a pressure range of 700-800 psi, as this should provide enough power to clean the surface without risking damage.
- Ensure the flow rate is high enough to effectively clean the asphalt without applying too much concentrated pressure in one area.
Methodical Cleaning
- Work systematically, moving from one side of the driveway or parking lot to the other, avoiding concentrated pressure in any one spot for too long.
- For sloped surfaces, start at the high end and work your way down to the low end. This will prevent dirt and debris from being blasted onto the already cleaned areas.
- Maintain a consistent, even pace to ensure a thorough and uniform cleaning across the entire surface.
Avoiding Damage
- Steer clear of using surface cleaners, as they can be too harsh and potentially damage the asphalt. Instead, opt for a wand with a high flow rate and low pressure.
- Be cautious not to scratch the surface, especially on older asphalt, as it can be more difficult to clean and more prone to damage.
- Avoid using turbo nozzles, as they can concentrate the pressure and cause localized damage to the asphalt.
Technical Specifications
Pressure Washer Settings
- Use a pressure washer with a low to moderate pressure setting, typically around 700-800 psi, to avoid damaging the asphalt.
- Ensure the flow rate is high enough to effectively clean the surface without applying too much concentrated pressure. Aim for a flow rate of at least 2.5 gallons per minute (GPM).
Tips and Nozzles
- Use a wide fan tip, such as a green or white tip, to distribute the pressure more evenly across the surface and reduce the risk of damage.
- Avoid using turbo nozzles, as they can concentrate the pressure and cause localized damage to the asphalt.
- Maintain a distance of at least 6 inches between the nozzle and the asphalt surface to prevent direct, high-pressure contact.
Chemicals and Cleaning Solutions
- Use asphalt-appropriate cleaners and degreasers to avoid damaging the surface. Avoid caustic chemicals and bleach, as they can dry out the asphalt and cause it to lose its integrity.
- Look for cleaning solutions that are specifically formulated for use on asphalt surfaces, as they will be less likely to cause any adverse effects.
- Perform a spot test in an inconspicuous area before applying the cleaning solution to the entire surface to ensure compatibility and safety.
Additional Tips and Considerations
Frequency of Cleaning and Sealing
- Clean and reseal your asphalt driveway or parking lot every 1-2 years to maintain its appearance and extend its lifespan.
- Regular cleaning and sealing can help prevent the formation of cracks, potholes, and other surface damage, ultimately saving you money in the long run.
Alternatives to Pressure Washing
- If a pressure washer is not available, you can use a large bucket, push brush, and asphalt-appropriate cleaner to manually scrub the surface.
- This method is more time-consuming but can be an effective alternative, especially for smaller areas or spot cleaning.
By following these techniques and technical specifications, you can effectively clean your asphalt surfaces with a pressure washer while minimizing the risk of damage. Remember to always prioritize safety and consult with a professional if you have any concerns or questions about the process.