Mould grows on walls when airborne mould spores land on damp surfaces and find the right conditions to thrive.
Here's a breakdown of the process:
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Mould Spores Are Everywhere: Microscopic mould spores are present in the air both indoors and outdoors. They're a natural part of the environment.
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Landing on a Suitable Surface: These spores circulate until they land on a surface.
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The Importance of Dampness: The critical factor for mould growth is moisture. Walls become damp due to:
- Leaks: Plumbing leaks, roof leaks, or leaks from appliances.
- Condensation: Warm, moist air coming into contact with cool surfaces (especially in bathrooms and kitchens).
- Rising Damp: Moisture rising from the ground through the walls.
- Poor Ventilation: Inadequate airflow traps moisture.
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The Right Conditions: Mould thrives in environments that are:
- Damp: Essential for spore germination and growth.
- Warm: Mould prefers temperatures between 60°F and 80°F (15°C and 27°C), though some can grow in colder conditions.
- Nutrient-Rich: Mould feeds on organic materials found in drywall, paint, wallpaper, dust, and other common wall components.
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Germination and Growth: Once a spore lands on a damp, nutrient-rich surface, it germinates and begins to grow, sending out hyphae (tiny root-like structures) to digest the material it's growing on.
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Visible Mould: As the mould colony grows, it becomes visible as fuzzy or slimy patches on the wall. These patches can be various colors, including black, green, brown, white, or grey.
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Rapid Development: Under ideal conditions, mould can start to grow within 24-48 hours. A small spot can quickly expand into a larger problem if the source of moisture is not addressed.
Key Steps to Prevent Mould Growth:
- Control Moisture: Identify and repair any leaks promptly. Improve ventilation in bathrooms and kitchens. Use dehumidifiers to reduce humidity levels.
- Clean Regularly: Remove dust and dirt, which can serve as a food source for mould.
- Use Mould-Resistant Products: When painting or renovating, use mould-resistant paints and materials.
Addressing Existing Mould:
- Identify and Fix the Moisture Source: This is the most crucial step. Cleaning the mould without addressing the underlying moisture problem will only provide a temporary solution.
- Clean the Affected Area: Depending on the extent of the mould, you may be able to clean it yourself using a mould-killing cleaner and appropriate safety precautions (gloves, mask, eye protection). For larger infestations, it's best to consult a professional mould remediation service.
