Power washing can be an effective way to clean aboveground storage tanks, but it should be done with care. Keeping the tank clean helps prolong paint life and makes it easier to spot problems. If the tank system is properly constructed and maintained, pressure washing should not pose a major issue. However, certain precautions are necessary to avoid accidental damage or contamination.
Using a Proper Cleaning Solution
Since the goal of cleaning the tank is to remove dirt, the use of a proper cleaning solution can help get the tank clean faster with less high pressure water. Also, if some of the staining is petroleum, the cleaning solution will help remove those stains. Choose a cleaning solution that is compatible with the tank paint and the surrounding equipment.
Protecting Tank Integrity During Cleaning
During the washing of a tank there is a risk of allowing water to enter the tank or its interstitial space (the space between the inner and outer tank walls, if applicable). The tank fittings, when in good repair, can prevent normal precipitation from entering the tank but pressure washing can force water past the seals on these devices. This can happen through:
- Tank vents
- Fittings
- Openings or compromised seals
- Tank connection points
- Tank electrical components
These components are designed to handle normal environmental exposure—such as rain or snow—but not the direct force of a power washer. Care should be taken to not direct the pressure washer stream at these tank components.
Before You Wash: Inspection is Key
Before washing the tank, it’s recommended to:
- Inspect all tank appurtenances (vents, caps, hatches, etc.)
- Check that seals and fittings are in good condition
- Repair or replace any components that appear worn, cracked, or loose
Keep in mind that tanks needing cleaning are not typically new—age and wear may compromise components over time, increasing the risk of water intrusion.
After Washing: Verify and Monitor
Once washing is complete:
- Inspect the tank and interstitial space for signs of water intrusion
- Consider monitoring both areas before and after washing to ensure nothing unexpected occurred during the cleaning process
This added step can help prevent long-term issues caused by unnoticed water ingress.
Bottom Line: Yes, You Can Wash—With Caution
With the right inspection, maintenance, and care, pressure washing an aboveground storage tank is safe. Just be smart about how and where you spray. Focus on protecting vents and fittings, and always confirm your system is in good condition before starting the job.
A little preparation goes a long way.
