About house washing
The green and grey film that creeps across siding is algae and mildew feeding on the surface. It is not dirt, which is why hosing it down does nothing and why it comes back faster each year once it takes hold.
Soft washing, not pressure washing
A soft wash runs at roughly garden-hose pressure and does the work with a cleaning solution rather than force. The solution kills the organism at the root, so the surface stays clean far longer than it would if the growth were simply blasted off. High pressure on vinyl is the classic mistake: it drives water up behind the panels, where it sits in the wall cavity and has no easy way out.
What it will and will not fix
Washing removes organic growth, pollen, spider webbing and general grime, and it is often the difference between siding that looks tired and siding that looks new. It will not restore vinyl that has faded from UV, and it will not hide chalking — the powdery residue on older panels that comes off on your hand. Those are refinishing or replacement problems, not cleaning problems.
Why the north side is always worse
Growth needs moisture, and the elevation that gets least sun stays damp longest. In Georgia that is usually the north and shaded sides, which is why one wall can look filthy while the sunny side looks fine. Overhanging trees and irrigation spray have the same effect wherever they land.
What moves the price
- Square footage and how many storeys
- How heavy the growth is — light film versus years of build-up
- Access: fences, slopes, tight side yards and dense planting all slow the job
- Whether gutters, soffits or a deck are being done at the same time
- Delicate landscaping that needs protecting
This is why a photo prices most jobs without a visit.