GEKO GmbH

How Facade Cleaning Helps with Algae and Mold

What is often overlooked: Not every dark coating automatically means a renovation case. In practice at GEKO GmbH it repeatedly shows that the right initial assessment yields more than reflexively reaching for a new coat.","articleBody":"The most important thing first\n\nFor superficial algae, fungal and fine dust contamination on an intact EIFS facade, a professional facade cleaning is often sufficient. If the mineral top plaster does not chalk, does not peel, and the substance is intact, the facade can often be cleaned gently instead of being painted anew. In a practical case at GEKO GmbH, this required CHF 248,000 instead of CHF 920,000.\n\nWhat is often overlooked: Not every dark coating automatically means a renovation case. In practice at GEKO GmbH it repeatedly shows that the right initial assessment yields more than reflexively reaching for a new coat.\n\nHow to recognize an intact facade with algae infestation?\n\nThe condition of the plaster is decisive. In the described practical case the mineral top plaster was intact, did not chalk, and showed no structural delamination. Then it strongly suggests the coating is superficial and cleaning is more sensible than a complete coating renovation.\n\nThe plaster is firm and still bearing.\n\nThere are no delaminations or open damages.\n\nThe coating sits on the surface, not in the building substance.\n\nThe cause is biological or dirt-related surface contamination.\n\nHow was the cleaning conducted at GEKO GmbH specifically?\n\nIn a project in the Swiss plateau, 11 multi-family houses with a total of 12,500 m² EIFS facade were treated. GEKO GmbH cleaned directly from ground level with carbon telescopic wands up to 15 m high, without scaffolding or aerial platforms, and then rinsed gently with pressure-regulated hot water below 20 bar. Finally, a hydrophobic coating with long-term protection against renewed infestation was applied.\n\nCHF 248'000 Kosten der Reinigung im Projekt 2025\n\nCHF 920'000 Budget des Neuanstrichs im Projekt 2025\n\n3.5 Wochen Dauer der Reinigung im Projekt 2024\n\n28 Wochen Dauer des geplanten Neuanstrichs im Projekt 2024\n\n5 bis 7 Jahre Verlängerung der Fassadenlebensdauer ohne Eingriff in die Bausubstanz\n\nGEKO GmbH\n\nSuperficial algae and mold contamination on an intact plaster can often be cleaned in a substance-preserving manner instead of repainting the facade.\n\nWhy is repainting often the more expensive solution?\n\nContrary to common belief, the most expensive solution is not always the safest. In the practical case, repainting costs were CHF 920,000 because scaffolding, crack repair, and a double silicone acrylic coating were planned. Cleaning with long-term protection cost CHF 248,000, i.e., CHF 672,000 less.\n\nComparison from the 2025 practical case\n\nVariant\n\nCosts\n\nDuration\n\nIntervention\n\nRepaint\n\nCHF 920'000\n\n28 weeks\n\nScaffolding, crack repair, double silicone acrylic coating\n\nCleaning with long-term protection\n\nCHF 248'000\n\n3.5 weeks\n\nWork from ground level, gentle washing, hydrophobization\n\nWhat mistakes are particularly common in facade cleaning?\n\nThe most common mistake is making a decision based on appearance rather than substance. If you immediately plan a repaint for purely biological surface contamination, you quickly pay for work that is technically unnecessary. That is why an on-site assessment belongs at the beginning, not the end.\n\nOnly assess the color and not the plaster.\n\nSet up scaffolding and repainting even though the substrate is intact.\n\nUse too high a pressure and risk the insulation plaster structure.\n\nDo not plan long-term protection and later get the infestation again.\n\nImportant practical point\n\nWith intact mineral top plaster, first check whether a gentle cleaning suffices. Early renovation creates unnecessary costs and longer downtimes.\n\nWhen is DIY sensible, when is a pro needed?\n\nFor facades with biological coating, DIY is only sensible where the situation is clear and small-scale. As soon as the area is larger, height increases, or the substance remains unclear, expertise, coordinated agents, and a clean approach are required. GEKO GmbH works here with specialized systems for facade, roof, stone, and concrete.\n\nHave plaster condition checked on-site.\n\nIf the substrate is intact, evaluate cleaning as an option.\n\nChoose appropriate cleaning agents and pressure values.\n\nPlan long-term protection or hydrophobic coating.\n\nIf in doubt, engage a professional company.\n\nFrequently asked questions about cleaning facades with algae or mold\n\nCan a heavily dirty facade still be cleaned?\n\nYes, if the substrate is intact and the infestation remains superficial. The amount of discoloration is not the only decisive factor; the plaster condition matters most. Only when the substance is damaged does it become more of a renovation case.\n\nWhy is long-term protection after cleaning sensible?\n\nBecause cleaning alone removes the existing coating, but does not automatically prevent re-colonization. A hydrophobic coating or a suitable protection system makes the surface less prone to attack. This is especially helpful for facades exposed to the weather.\n\nHow quickly can such a project be completed?\n\nIn the described case, cleaning took 3.5 weeks or 18 workdays. A repaint was planned to take 28 weeks, much longer. For administrations and owners, this difference is often an important part of the decision.\n\nIs a repaint never necessary?\n\nYes, if the plaster is damaged, cracks are present, or the facade layer is no longer intact. Then cleaning is not enough because the problem lies deeper. The core question is always first: surface or substance?\n\nFor GEKO GmbH, the most important point is the sequence: first assess, then decide. Those who correctly assess the facade on-site avoid unnecessary costs and often gain several years of usable life.\n\nIf you need a solid decision between cleaning and repainting, a professional assessment of the facade on-site is worthwhile. Exactly there it shows whether a gentle procedure suffices or whether a renovation is truly necessary.\n\nFassadenzustand prüfen lassen\n\nGEKO GmbH, Wiler B. Utzenstorf","dateModified":"2026-08-31T10:02:37.297Z","author":{"@type":"Person","name":"Sergio Donadei","url":"https://maxq.ch/en/companies/geko-gmbh"},"keywords":["scrubbing machine","single-disc machine","floor cleaning machine","cleaning machine","facade cleaning","algae infestation","mold infestation"],"articleSection":"Rental of Machinery & Equipment","wordCount":898,"about":{"@id":"https://maxq.ch/en/companies/geko-gmbh#localbusiness"},"speakable":{"@type":"SpeakableSpecification","cssSelector":["h1"]}},{"@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Directory","item":"https://maxq.ch/en/search"},{"@type":"ListItem","position":2,"name":"Rental of Machinery & Equipment","item":"https://maxq.ch/en/industries/business-technical-services"},{"@type":"ListItem","position":3,"name":"GEKO GmbH","item":"https://maxq.ch/en/companies/geko-gmbh"},{"@type":"ListItem","position":4,"name":"Knowledge","item":"https://maxq.ch/en/knowledge"},{"@type":"ListItem","position":5,"name":"How Facade Cleaning Helps with Algae and Mold","item":"https://maxq.ch/en/knowledge/how-facade-cleaning-helps-with-algae-and-mold"}]},{"@type":"FAQPage","mainEntity":[{"@type":"Question","name":"Can a heavily dirty facade still be cleaned?","acceptedAnswer":{"@type":"Answer","text":"Yes, if the substrate is intact and the infestation remains superficial. The amount of discoloration is not the only decisive factor; the plaster condition matters most. Only when the substance is damaged does it become more of a renovation case."}},{"@type":"Question","name":"Why is long-term protection after cleaning sensible?","acceptedAnswer":{"@type":"Answer","text":"Because cleaning alone removes the existing coating, but does not automatically prevent re-colonization. A hydrophobic coating or a suitable protection system makes the surface less prone to attack. This is especially helpful for facades exposed to the weather."}},{"@type":"Question","name":"How quickly can such a project be completed?","acceptedAnswer":{"@type":"Answer","text":"In the described case, cleaning took 3.5 weeks or 18 workdays. A repaint was planned to take 28 weeks, much longer. For administrations and owners, this difference is often an important part of the decision."}},{"@type":"Question","name":"Is a repaint never necessary?","acceptedAnswer":{"@type":"Answer","text":"Yes, if the plaster is damaged, cracks are present, or the facade layer is no longer intact. Then cleaning is not enough because the problem lies deeper. The core question is always first: surface or substance?