The short answer
Most concrete driveways in Knoxville, Maryville, Lenoir City, and the surrounding East Tennessee area should be professionally pressure washed once a year. Heavily shaded driveways, driveways under tree cover, and high-traffic driveways often need it every six months.
If you can see green or black film along the edges, dark stripes where tires sit, or red clay tracked in from a recent rain — your driveway is overdue. Concrete looks dingy long before most homeowners notice, because the change happens slowly week to week.
Why East Tennessee driveways get dirty faster than most
Our climate is the main reason. East Tennessee gets warm, wet summers and mild, damp winters — perfect conditions for algae, mildew, and biofilm to grow on concrete. Add pollen-heavy springs and the red clay common in our soil, and a driveway can shift from "clean" to "dingy" in a single season.
Tree cover makes it worse. Oaks, maples, and pines drop tannins, sap, and needles that feed organic growth. Shaded driveways stay damp longer after every rain, which is exactly what mildew needs to take hold.
What changes the cleaning schedule
There is no single answer that fits every property. The right interval depends on a handful of factors:
- Sun exposure — driveways in full sun dry faster and stay cleaner longer
- Tree cover — leaf drop, sap, and shade all accelerate staining
- Traffic — multi-car families and contractor traffic put down more tire marks and oil
- Slope — flat driveways pool water and pollen; sloped driveways shed both
- Whether the driveway is sealed — sealed concrete stays cleaner two to three times longer
Signs you should book a clean now
Even if it has been less than a year, book a clean if you see any of the following: dark stripes where tires sit, a slick or slippery feel underfoot after rain, a green or black tint along the edges, tannin stains under trees, or red clay that water alone won't lift.
Sellers preparing to list a home should always wash the driveway. It is one of the highest-impact, lowest-cost curb-appeal moves you can make before photos.
Can I just rent a pressure washer?
You can — but the result is rarely what homeowners expect. Consumer pressure washers don't move enough water to spin a true surface cleaner, which is what produces the even, streak-free finish you see in professional jobs. Without a surface cleaner, a wand alone leaves zebra stripes that are visible for years.
There is also a chemistry question. Mildew, algae, oil, rust, and tannin stains each need a different pre-treatment. Water alone hides the problem for a few weeks; the right cleaner kills organic growth at the root so the clean lasts months longer.
Bottom line
Plan on once a year for most East Tennessee driveways. Twice a year if you are under heavy tree cover, on a shaded lot, or you simply want the driveway to stay sharp through every season. Pair the clean with a concrete sealing every 3–5 years and you will spend significantly less time worrying about it.