Before-and-after photos sell exterior cleaning, and the good ones are genuine. But they are also selected, and they are almost always of the surfaces that respond best.
Here is what actually comes back, what partially comes back, and what does not — so you know which you are buying before you pay for it.
What produces a dramatic result
These are the jobs that photograph well, and they are not misleading.
Organic growth on any sound surface. Green and black algae, mould and mildew on render, painted walls, fencing and paths. This is a chemical kill and the difference is total. The most dramatic results in exterior cleaning are all of this type.
Concrete driveways with surface grime. Years of traffic film, dirt and light algae come off cleanly, and the contrast against the uncleaned section is genuinely striking.
Paths and paved areas with moss and dirt.
Roofs with moss and algae, treated chemically.
In all of these, what was on the surface has been removed and what is underneath was in good condition.
What improves substantially but not completely
Oil stains. Fresh ones usually come out. Old ones that have soaked deep into unsealed concrete generally lighten considerably and leave a shadow. A poultice gets further but rarely to nothing — here.
Rust staining. Responds well to the right chemistry, though deep staining in porous concrete can leave a trace — here.
Lichen. Dies and releases over weeks rather than on the day. The honest before-and-after for lichen is taken a month apart, not an hour — here.
Weathered timber. Cleaning removes the grey surface layer partially; full restoration needs sanding.
What will not come back
This is the part worth knowing before the quote.
Etched glass. Mineral deposits left long enough pit the glass itself. No clean fixes it — here.
Chalked and faded Colorbond or powder coat. The pigment has degraded. Washing removes the loose chalk; the fade is permanent, and aggressive washing makes it patchy — here.
Etched stone. Acid damage to limestone, travertine or marble is a change in the surface, not a stain.
Eroded concrete from previous over-aggressive pressure washing. The cement paste is gone and the aggregate is exposed. Only resurfacing changes it — here.
Iron spotting in basalt. The iron is in the stone — here.
Tannin deep in old concrete. Lightens; rarely disappears.
Paint ghosting. Paint that soaked into porous concrete leaves a shadow after the surface paint is removed — here.
The patch problem
Worth understanding, because it causes more disappointment than anything else.
Cleaning one area of a surface makes it look different from the rest — cleaner, lighter, sometimes smoother. On a uniform driveway, treating a single stained patch can look worse than the stain did.
Which is why a proper job cleans the whole surface to a consistent finish rather than spot-treating, and why a quote for one patch is often the wrong quote.
How to judge a contractor’s photos
- Same angle, same framing, same time of day. Different lighting does a lot of work in a bad before-and-after.
- A wet after shot against a dry before shot exaggerates the difference — wet concrete always looks darker and richer.
- Ask for photos of a surface like yours, not their best job.
- Ask what they could not remove. An operator who says everything comes out, on an old driveway, has not looked closely.
What we do
Photo reports on every job, before and after, from the same positions, and a note on anything that did not come out and why.
And at quote stage, an honest answer about which category your surface is in. Setting the expectation correctly is most of the job — more in how a job runs, start to finish.
