Most Florida homes need washing every 12 to 24 months. That's noticeably more often than the "every two to three years" advice you'll find on national sites, and the reason is simple: those articles are written for climates where exterior growth is seasonal. In Florida it's continuous. Your interval inside that 12–24 month band depends almost entirely on how quickly your walls dry out.
Below: why Florida is genuinely different, the five conditions that halve your interval, a breakdown by Jacksonville area, the best time of year to book, and how to tell you've left it too long.
The short answer
Work it out from your own conditions rather than a national average:
- Every 24 months — open lot, full sun on most elevations, newer construction, no overhanging trees, more than a mile inland.
- Every 18 months — partial shade, some tree cover, average suburban lot. This is where most Jacksonville homes sit.
- Every 12 months — heavy canopy, coastal, backing onto water or marsh, or north-facing walls that never get sun.
- Every 6 months — rare, but genuine for deeply shaded homes on creeks and for rental or commercial property where appearance is the product.
Why Florida is different
Three things stack up here that don't stack up in most of the country.
Humidity is year-round. Jacksonville averages roughly 50 inches of rain a year and stays humid through most of it. Algae and mildew need moisture, warmth and a food source; two of those three are permanently available.
There's no hard winter. In northern states a freeze knocks growth back every year, which effectively resets the clock. Here it just slows down for a few weeks.
The organisms are established. Gloeocapsa magma — the black roof streaking — is endemic across the south-east. Spores are constantly in the air, so re-colonisation starts the day after you clean.
The practical consequence: whether you're on a 12 or 24 month cycle, the method matters more than the interval. A soft wash that kills the organism resets you to zero. A pressure-only rinse leaves the roots and you're back where you started in eight weeks regardless of how often you do it.
The five factors that shorten it
Each of these roughly halves the time before growth is visible again. If two or more apply to you, you're on an annual cycle.
| Factor | Effect | Why |
|---|---|---|
| Heavy tree canopy | 2× faster | Walls never dry; leaf litter and tannins feed growth |
| Within 1 mile of the coast | 2× faster | Salt aerosol is hygroscopic — holds moisture on the wall |
| Backing onto water or marsh | 1.5–2× faster | Constant humidity on the water-facing elevation |
| North-facing walls | 2× faster on that face | Least direct sun, so slowest to dry and no UV kill |
| Sprinklers hitting the wall | 2× faster, plus rust | Permanent damp line, and iron staining on top |
| Blocked or overflowing gutters | Localised, severe | Water runs down the wall continuously after rain |
Two of those you can fix for free. Turning a sprinkler head so it stops throwing water at your siding, and clearing your gutters, will do more for your exterior than an extra wash a year.
Interval by Jacksonville area
We've cleaned across the First Coast long enough to see clear patterns by neighbourhood. These are the intervals we actually recommend:
| Area | Interval | Driving factor |
|---|---|---|
| Mandarin | 12 months | Heaviest live oak canopy in Jacksonville |
| Atlantic Beach | 12 months | Salt plus maritime oak shade together |
| Jacksonville Beach | 12 months | Airborne salt film |
| Ponte Vedra Beach | 12–18 months | Marsh humidity; HOA appearance standards |
| St. Johns (32259) | 12–18 months | Well-water rust; shade in older Julington Creek |
| Yulee | 12–18 months | Pine pollen and marsh damp |
| Orange Park | 18 months | Mature but not dense tree cover |
| Nocatee | 18–24 months | Open, new construction, good sun exposure |
The best time of year to book
Late April to May in north Florida, and the reason is pollen.
Slash and loblolly pines drop from roughly February through April. Pine pollen isn't like dust — the grains have a waxy coat that makes them cling, and plain water won't shift the film. Wash your house in March and you'll be looking at a yellow-green house again within a fortnight. This matters most in Yulee and Nassau County, which is pine country, but it applies across the whole area.
Autumn — October into November — is the second-best window. Growth from the summer is at its heaviest, so the visual improvement is dramatic, and you go into the damp winter months with a clean surface.
The one time we'd avoid is deep summer. Not because results suffer, but because the solution dries on the wall too fast in 95°F heat, which means working in smaller sections and taking longer.
Signs you've left it too long
Check the north and east elevations first — they always go first. In rough order of severity:
- A dusty film that comes off on your hand. Earliest stage; easy clean.
- A green tint at the base of walls, especially behind shrubs.
- Dark streaking under gutter joints and window sills.
- Black spotting on soffits and the underside of eaves.
- Black streaks running down the roof slope — that's gloeocapsa magma, and it's consuming your shingles.
- Visible green on the driveway and walkway — which is also a slip hazard.
Once you're at black spotting on soffits, expect a second application and roughly 15% more on the price. It's cheaper to be early.
My honest take
I'd rather you washed less often and did it properly than signed up to an annual plan you don't need. Genuinely — if your house is in open sun in a newer subdivision, a wash every two years is fine, and anyone pushing you to annual is selling rather than advising.
The exception I'd argue the other way on is roofs. People leave those far too long because the streaking creeps up gradually and you stop seeing it. The algae is eating the limestone filler in your shingles the entire time. Every two to three years on a roof is real maintenance, not cosmetics.
And the cheapest thing you can do costs nothing: walk around your house once a year, look at the north wall, turn any sprinkler that's hitting the siding, and clear the gutters. That alone pushes most homes from a 12-month cycle to an 18-month one.
Not sure which band you're in? Send us a photo of your worst elevation and we'll tell you honestly — including if the answer is "leave it another year". You can also read what we do on the main pressure cleaning page or check your specific area.
