The Florida schedule
How often should you pressure wash a house in Florida?
The national answer is every one to two years. Florida runs on a different clock — humidity feeds algae year-round, and the shady side of a Jacksonville house can show green in eight months. Here is the honest surface-by-surface schedule.
Published
The short answer
House wash: every 12 to 18 months, sooner if you are under oak canopy or near the water. Roof: a soft wash treatment every 3 to 5 years, with inspections in between. Driveway and concrete: once a year. Pavers: cleaned every year or two, sealed every 3 to 5. Pool cage: annually.
Those numbers assume Florida. A house in Denver can stretch to three years. A house in Fleming Island under live oaks, ten minutes from Doctors Lake humidity, cannot. The algae does not care what the national blogs say.
Why Florida is on a different clock
North Florida runs 70 to 90 percent humidity most of the year, and algae needs three things: moisture, shade, and a surface to eat. Every house in Jacksonville has all three. The north and west walls — the ones the sun never hits — grow Gloeocapsa magma first. That is the black streaking on shingles and the green film on siding, and it is alive.
Then add the local accelerants. Oak canopy drops tannins that stain stucco. Salt air off the St. Johns and the ocean leaves a film that holds moisture against the paint. Pollen season coats everything in spring. A First Coast house is basically a petri dish with a mailbox.
The surface-by-surface schedule
House wash, soft wash: 12 to 18 months. If the north wall greens up early, that is your clock, not the calendar. Roof: a professional soft wash treatment every 3 to 5 years keeps the black algae from eating the limestone filler out of the shingles — which is how a roof dies early. Light streaking between treatments is normal; heavy black coverage is not a wait-and-see situation.
Driveway and sidewalks: yearly. Concrete holds moisture in its pores, and the shaded strips along the house line go green first. Pavers: clean every 12 to 24 months, seal every 3 to 5 years — sooner if the sand keeps washing out of the joints. Screen enclosure and lanai: annually, because the frame oxidizes and the mesh holds pollen.
What waiting actually costs
A roof is the expensive lesson. Black algae is not cosmetic — it feeds on the limestone in asphalt shingles, granules loosen, and the roof ages years early. Manufacturers will void a warranty over pressure damage, and an untreated roof in river humidity can lose a third of its life. A roof cleaning costs hundreds; a roof replacement costs a house payment times sixty.
Paint is the second cost. Algae holds moisture against siding and trim, and moisture is what peels paint and rots fascia. The wash is cheaper than the repaint by an order of magnitude. And if you live in an HOA, the third cost is the letter — most First Coast associations cite dirty roofs and driveways on a schedule, and the fine math is never in your favor.
The signs your house is telling you
Green film on the north wall. Black streaks running down the roof planes. Green stripes along the driveway edges where the sun does not reach. Mildew behind the porch lattice. Any one of these means the schedule already started — the question is just whether you set the appointment or the algae does.
If you keep hitting these signs early every year, you are a candidate for the Autopilot Plan: a founding clean plus scheduled care, so the calendar owns the maintenance instead of you. Same surfaces, same crew, no phone tag.