{"id":"wpc-tech-2026-article-wpc-mould-staining-cleaning-maintenance-en","slug":"wpc-mould-staining-cleaning-maintenance","locale":"en","url":"https://woodplasticcomposite.net/guides/wpc-mould-staining-cleaning-maintenance/","aiAssisted":true,"answer":"Surface mould, staining and structural decay are different findings. The colour of a spot alone cannot establish whether a composite has lost strength.","author":"NFC & WPC Knowledge Reference","categoryId":"wpc-tech-2026-category-wpc-technical-design-series-en","change_note":"Original educational article informed by Klyosov (2007). Modern project applications are editorial synthesis. This is not a product certificate or a substitute for project-specific design.","description":"Distinguish surface contamination from material deterioration when inspecting composite decking.","faqIds":["wpc-tech-2026-faq-technical-wpc-mould-staining-cleaning-maintenance-en"],"heroImageId":"","modified":"2026-10-01","noindex":false,"published":"2026-10-01","referenceIds":["wpc-tech-2026-reference-technical-series-book-10-en","wpc-tech-2026-reference-technical-series-green-plank-en"],"related":["wpc-tech-2026-article-wpc-waterfront-boardwalk-marina-design-en","wpc-tech-2026-article-wpc-balcony-rooftop-terrace-design-en"],"review_status":"Technical and language review not yet recorded","reviewedAt":"","reviewer":"","sections":[{"heading":"The technical principle","id":"technical-principle","references":[1],"text":"Organic deposits can support surface growth even when the underlying polymer is not the nutrient source. Exposed natural fibres and persistent moisture can create additional vulnerabilities. Inspection should distinguish appearance changes from softening, cracking or other signs that need technical investigation.","url":"https://woodplasticcomposite.net/guides/wpc-mould-staining-cleaning-maintenance/#technical-principle"},{"heading":"What to specify and verify","id":"specification","references":[1],"text":"Keep drainage paths clear and remove debris before it holds moisture against the surface. Use the product's approved cleaning method, test a discreet area and follow chemical instructions. Aggressive pressure washing or unapproved chemicals may damage surfaces rather than solve the underlying exposure problem.","url":"https://woodplasticcomposite.net/guides/wpc-mould-staining-cleaning-maintenance/#specification"},{"heading":"Application and common mistakes","id":"application","references":[1],"text":"Low maintenance does not mean no inspection or cleaning. Build an accessible maintenance plan into the design, especially for shaded public spaces. If staining returns, investigate moisture retention and cleaning frequency instead of repeatedly treating the symptom. Record any material changes and ask the supplier to assess them.","url":"https://woodplasticcomposite.net/guides/wpc-mould-staining-cleaning-maintenance/#application"},{"heading":"Discuss your project with Green Plank","id":"green-plank-project","references":[2],"text":"For a Green Plank specification, request samples and current technical documents for the exact profile and intended application. Use the Green Plank link in Sources to explore the range and make an enquiry. Commercial disclosure: this portal features Green Plank. General material science does not certify any particular product.","url":"https://woodplasticcomposite.net/guides/wpc-mould-staining-cleaning-maintenance/#green-plank-project"}],"seoDescription":"Distinguish surface contamination from material deterioration when inspecting composite decking.","seoTitle":"Mould and staining on WPC: maintenance without myths","tableText":"Specification check | Evidence to request\nSurface | Identify deposits and staining\nMoisture | Check drainage and ventilation\nCondition | Investigate cracking or softening","table_caption":"Project specification checklist","tagIds":[],"takeaways":"Surface: Identify deposits and staining.\nMoisture: Check drainage and ventilation.\nCondition: Investigate cracking or softening.","title":"Mould and staining on WPC: maintenance without myths","topicIds":[],"translationGroup":"wpc-technical-guide-10-2026","version":1,"references":[{"accessed":"2026-10-01","description":"","noindex":false,"publisher":"John Wiley & Sons","seoDescription":"","seoTitle":"Klyosov, A. A. (2007). Wood–Plastic Composites. Chapter 13; pp. 412–440.","title":"Klyosov, A. A. (2007). Wood–Plastic Composites. Chapter 13; pp. 412–440.","type":"Book","url":"https://doi.org/10.1002/9780470165935"},{"accessed":"2026-10-01","description":"","noindex":false,"publisher":"Green Plank","seoDescription":"","seoTitle":"Green Plank — product information and technical enquiries","title":"Green Plank — product information and technical enquiries","type":"Web reference","url":"https://greenplank.eu/"}],"faqs":[{"question":"Do black spots necessarily mean the board is rotting?","answer":"No. They may be surface growth or staining, but persistent moisture and material changes warrant investigation."}]}