The joints are green, and you've heard cleaning makes it worse
Look down at a paver driveway out here in September and the joints tell the story before the pavers do. Green fuzz along the seams. A few weeds pushing up between the stones near the edge. A dark film across the low spots where water sits for a day after a storm. The pavers themselves might still look fine from the street, and the lines between them look like something is growing out of the ground.
Then there's the story that keeps people from calling anybody. Somebody had their driveway cleaned, the crew blew the joint sand out, and a few months later there were more weeds than before plus ant hills in the low spots. That story shows up in every Florida homeowner thread about pavers, and it isn't made up. It happens. It just doesn't happen for the reason most people assume.
It's not that cleaning pavers is risky by nature. It's that a paver joint is a soft target sitting in the middle of a hard surface, and one specific way of working goes straight through it.
What actually blows the joint sand out
Joint sand sits in a narrow gap between hard stones. Nothing holds it there except its own weight and whatever has settled on top of it over the years. Point a narrow high pressure tip down into that gap and you're not cleaning a driveway anymore, you're cutting a trench. A tight tip concentrates everything the machine has into a line about as wide as a pencil. That line beats sand every single time.
That's the whole failure. Not the machine, not the trailer in the driveway, not the fact that the pavers got washed at all. It's a narrow tip, held close, aimed into the one part of the surface that can't take it. Someone moving fast with a wand will strip the joints across a whole driveway without ever meaning to, because from standing height it just looks like the driveway is getting clean.
The tool and the angle are the fix, not skipping the job
A surface cleaner is a housing that rides flat on the slab with jets spinning underneath it. Instead of one hard line held in one place, the force gets spread across the full width of the head and kept moving. Hard flat surfaces like concrete and paver stone can take real pressure through a tool like that, because the water is working across the face of the stone rather than digging into a seam. That's the tool a driveway and paver cleaning runs on here.
Angle matters as much as the tool. Water aimed down into a joint goes into the joint. Water kept moving across the top of the stone cleans the top of the stone. That's the difference between a driveway that comes back clean with its joints intact and one that comes back clean and hollow. The longer version of the driveway pressure question is here, and the answer runs the same way for pavers as it does for a poured slab.
Joint sand is replaceable, and re-sanding is a normal step
Even on a careful job, some sand comes out. The top of a joint is already loose after a few rainy seasons, and rinse water carries loose grit with it. That's expected. Joint sand is a consumable, not structure, and putting fresh sand back into the joints after a clean is a normal part of the work rather than a repair for a mistake. The Concrete Masonry and Hardscapes Association publishes the technical guidance the paver trade works from on joints and bedding.
This is the part the horror stories leave out. The bad outcome isn't sand coming out. The bad outcome is sand coming out down to the bedding layer and nobody putting any back. If you're getting pavers cleaned by anyone, ask what happens to the joints afterward. That one question separates the two versions of this job.
It's also the reason the relative's driveway in that story ended up with ant hills. An empty joint is an open door. Fill the joints back up and that door closes on its own, without anything getting sprayed on your yard to make it happen.
The green film and the weeds are two different problems
Mold, algae and the dark film across the shaded end of the driveway are growth sitting on the surface. Growth responds to chemistry and a rinse, the same way it does on a wall. That part comes off, and the driveway looks like itself again the day the work is done.
Weeds are a seed problem. Seed blows in off the yard, lands in a joint, and the joint holds enough grit and moisture to sprout it. Cleaning takes out what's growing right now, which is why the surface looks so different afterward. It does not reach into the joint and change whether the next seed that lands there can take hold.
Why the shaded end and the low spots are always worse
Growth follows water and shade, not age. The end of the driveway under the oak, the strip along the north side of the house, the dip where a puddle sits after every afternoon storm: those hold moisture hours longer than the middle of the slab that bakes dry by noon. Same pavers, same age, completely different look.
Weeds follow the same map for the same reason. A joint that stays damp is a better place for a seed than a joint that dries out by lunchtime. So the low end of a driveway usually needs both things handled, the growth and the joints, while the sunny middle mostly just needs the film taken off.
What a cleaning will not do
It will not stop weeds from coming back. Nothing about washing a driveway changes the fact that seed lands in joints and the sun does the rest. Anyone telling you a cleaning ends the weed problem for good is selling something that doesn't exist. Expect them back. Expect the driveway to be a lot easier to stay on top of once the growth is gone and the joints are full again.
A cleaning also doesn't fix a paver that has sunk, a section that has shifted, or a base that settled after years of rain. Those are groundwork problems, and clean pavers on a settled base are still a settled base. Paver sealing is its own separate job with its own conversation, not something to staple onto a cleaning because a blog post brought it up.
Common questions
Will cleaning my pavers make the weeds worse?
Not if the joints get treated like joints. Weeds get worse after a cleaning when the sand is gone and nothing goes back in, because an empty joint holds more grit and more moisture than a full one. Clean stone and full joints is the outcome you're actually paying for.
Do the joints have to be re-sanded every time?
Not always. It depends on how much sand is in there to start with. Some driveways have already been washed hard once and need real sand work. Others just need the top of the joint topped off. Send photos and you'll get told which one yours looks like before anyone touches it.
Can I just pull the weeds and skip the cleaning?
You can, and plenty of people do. Pulling weeds handles the weeds. It leaves the black film, the green in the low spots and the dirty joint lines, which is usually what makes a driveway look tired from the street in the first place.
Send a photo of the driveway and one of a joint
Text two photos, one from standing height and one close enough to see into a joint line, and you'll get a real number back plus a straight read on whether those joints need sand. No appointment, nobody walking your property first. If you'd rather just talk it through, call (941) 257-8624, 8am to 7pm Monday through Saturday.