Bird Fouling Removal & Cleaning

Bird fouling is the job most often handed to whoever is available with a hose, and it's one of the few where that approach is actively dangerous. Dried guano contains bacteria and fungal spores, and the risk isn't from touching it — it's from disturbing it. Hosing or sweeping dried fouling aerosolises the dust and puts it straight into the breathing zone of whoever is doing the work and anyone nearby.

Done properly it's a controlled job with the right PPE, the right method and the right disposal. Done casually it's a health risk to a member of site staff who was only trying to be helpful.

Why it's a health issue

Guano can carry organisms associated with respiratory illness — psittacosis, histoplasmosis and cryptococcosis are the ones usually named — along with salmonella and E. coli. Actual infection is uncommon, and we're not in the business of alarming people, but the risk is real enough that it should be managed rather than ignored, particularly where the fouling is long-standing and dry.

The controlling factor is dust. Wet fouling is comparatively low-risk to handle with basic precautions; dried, powdered fouling disturbed by brushing or a jet becomes airborne, and that's the exposure route that matters.

So the method is always to wet it down thoroughly and let it soften before anything else happens, use appropriate respiratory protection and disposable coveralls, and bag the waste for correct disposal rather than washing it into a drain or sweeping it into a bin.

What it does to the building

Guano is acidic — strongly so when fresh — and it stays in contact with the surface for months or years.

On limestone and soft sandstone it etches and pits, and on a carved detail or an inscription that's irreversible loss. On metal it attacks protective coatings and accelerates corrosion, which matters on structural steelwork, balustrades and signage fixings. On painted surfaces it lifts and blisters the coating.

It also blocks things. Fouling accumulating in gutters, hoppers and outlets causes overflows, which soak the wall below and produce the damp and organic growth we then get called about separately. A surprising number of the green streaks we clean start as a blocked outlet under a roosting ledge.

And on walkways, steps and entrances it's simply a slip hazard, which for a public building or a retail frontage is a liability question rather than an aesthetic one.

How we clean it

Steam is particularly well suited to this work because the heat sanitises the surface as it cleans, which reduces the amount of chemistry needed on what is often a public-facing area. Where guano has been in place long enough to etch or stain stone, a poultice deals with the residual mark.

• Assess and cordon — establish the extent, the access and who needs to be kept clear
• Wet down thoroughly with a biocidal solution and allow it to soften — never disturb it dry
• Remove and bag the bulk material for correct disposal
• Clean the surface, usually with steam, which sanitises as it cleans
• Treat residual staining, with a poultice where guano has etched into stone
• Report the roosting points so the cause can be dealt with

Cleaning is the symptom, roosting is the cause

We'll be straight about this: cleaning fouling without addressing why birds are roosting there is a recurring cost with no end. The birds return to the same ledge, and you're booking the same clean next year.

We're cleaning specialists rather than a pest control company, so we don't install netting or spike systems ourselves. What we do is report exactly where the roosting is happening, with photographs from the access we've already got up there — which is genuinely useful information, because ledges and steelwork are hard to assess from the ground.

That report lets you get a proofing contractor in with a clear brief. The sensible sequence is clean first, proof immediately afterwards while the surface is clean, and then the cleaning becomes a one-off rather than an annual line in the budget. Where a client is arranging both, we'll happily coordinate so the access is shared between the two visits.

Access and timing

Most fouling is high up — ledges, parapets, canopies, signage, structural steelwork — so access is usually the item that shapes the job. If a MEWP is being mobilised, it's always worth doing everything else at that level in the same visit: gutters, high-level cleaning, signage washing.

Timing is worth thinking about too. Nesting birds are protected under the Wildlife and Countryside Act, and it's an offence to disturb an active nest. In practice that means work near likely nesting sites is best scheduled outside the main nesting season, and if we find an active nest we'll stop and tell you rather than press on. It's better to plan around that than discover it on the day the platform is booked.