A driveway is the job most people buy a pressure washer for, and the one where the gap between a good result and a disappointing one is almost entirely about sequence. Step five is the one everybody skips, and it is the step that does the cleaning.
First, work out which problem you have
A driveway usually has two or three unrelated problems, and they need different answers.
General grime — overall gray dulling, worse near the road. Comes off with water and a surface cleaner.
Algae and black growth — green film, dark patches, slippery areas in shade. This is the one that returns, and why a cleaned driveway often looks bad again by midsummer. Needs a cleaner that kills it.
Motor oil — dark patches where a car sits. Soaked into the slab. Pressure will not touch it at any PSI; it needs a pull-out stain remover, applied and left.
Products for each are in best concrete cleaners.
The tool that changes the job
A surface cleaner. A wand cleans a two-inch stripe and leaves overlap marks; a 14 or 15-inch head cleans an even disc three to five times faster. On a two-car driveway that is the difference between an afternoon and under an hour.
Size it to your machine’s flow rate, not your driveway — an undersized machine with an oversized head cleans worse than a correctly sized smaller one. How to check.
The three causes of stripes
A tipped head. Any lean puts one side of the disc closer to the slab. Four wheels mostly prevent it; with three, keep it consciously flat over expansion joints.
Walking too fast for your flow. If the bar is turning slowly, each spot gets hit less often and a brisk pace leaves banding. Slow down.
A partially blocked nozzle, which shows as a regular repeating pattern — surface cleaner not spinning.
Technique in detail: how to use a surface cleaner.
If you have no surface cleaner
Use a 25-degree green tip or a turbo nozzle, hold a consistent distance, and work in long overlapping sweeps in one direction. Expect it to take considerably longer and to show faint overlap marks, which is why the attachment exists.
Never hold a turbo nozzle or a 0-degree tip still. Pausing etches concrete permanently.
Pavers need one extra step
Any pressure cleaning of sand-jointed paving removes some jointing sand — a surface cleaner less than a wand, a turbo nozzle essentially all of it. Unfilled joints mean weeds next spring and eventually shifting pavers.
So: let the pavers dry fully, then sweep fresh jointing sand in and compact it. Polymeric sand costs more and resists weeds and washout better. This is also a good argument against the turbo nozzle on paving.
Should you seal it afterwards?
Optional, and if you are going to, cleaning first is mandatory and the slab has to be fully dry — usually a couple of dry days, longer for thick or shaded concrete. A sealer applied over damp concrete traps moisture and fails.
The machines with the flow to make this job quick are in best pressure washers for driveways.
