Understanding Mould

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Mould is a type of fungus that grows in damp, poorly ventilated environments. While small amounts of surface mould are often treated as a maintenance issue, uncontrolled or widespread mould growth can become an environmental biohazard.

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Mould reproduces by releasing microscopic spores into the air. These spores can travel throughout a property, settle on surfaces, and remain present even after visible mould has been removed. In severe cases, mould contamination affects not only walls and ceilings, but also air quality, furnishings, insulation, and structural materials.

When mould growth is extensive, persistent, or linked to health symptoms, it should be treated as a contamination issue rather than a cosmetic one.

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Common Causes

 

Mould thrives in environments where moisture is present over time.

Common contributing factors include:

• Poor ventilation in bathrooms, kitchens, and bedrooms

• Condensation caused by inadequate heating or insulation

• Leaking pipes, roofs, or appliances

• Flooding or water damage

• Long-term neglect or vacant properties

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In some cases, mould growth may indicate a hidden issue behind walls or under flooring. Treating only the visible mould without addressing underlying moisture can allow contamination to continue spreading unseen.

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Health Risks

Exposure to mould spores can affect people differently depending on the type of mould present, the extent of contamination, and individual vulnerability.

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Potential health effects include:

• Respiratory irritation and persistent coughing

• Worsening of asthma and other breathing conditions

• Allergic reactions such as sneezing, skin irritation, or watery eyes.

• Headaches and fatigue in prolonged exposure cases

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Children, elderly individuals, and those with weakened immune systems are particularly at risk. In heavily contaminated environments, prolonged exposure may present a serious health concern and should not be ignored.

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Black Mould

Black mould is often used as a general term, but it typically refers to Stachybotrys chartarum, a mould species associated with prolonged moisture exposure. This type of mould can produce mycotoxins, which may pose additional health risks when inhaled or touched.

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It is important to note that not all black-coloured mould is toxic, and not all toxic mould appears black. Visual identification alone is unreliable, which is why professional assessment is often required to determine the severity of contamination.

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Surface cleaning

Many mould issues appear to improve after wiping or using household cleaning products. However, this approach often removes only the visible growth while leaving spores embedded in surfaces or airborne.

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Incomplete treatment can:

• Allow mould to return quickly

• Spread spores to unaffected areas

• Give a false sense of safety

• In severe cases, disturbing mould without proper containment can worsen contamination rather than resolve it.

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When does it require specialist cleaning?

 

Mould may require specialist intervention when:

• Growth is extensive or recurring

• Multiple rooms or shared ventilation systems are affected

• There is a strong or persistent musty odour

• Occupants are experiencing health symptoms

• The property has suffered flooding or long-term water damage

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Specialist mould remediation focuses on containment, safe removal, decontamination, and prevention of further spread. Not just appearance.

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Professional Mould Remediation

 

A professional biohazard-led approach to mould contamination may include:

• Assessment of affected areas and contamination extent

• Containment to prevent spore spread

• Use of appropriate PPE and filtration equipment

• Removal of contaminated materials where necessary

• Decontamination of surfaces and air

• Safe disposal of contaminated waste

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The objective is to restore the environment to a condition that is safe to occupy, not simply to improve how it looks.

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Mould in rental or communal buildings

 

Mould contamination in rental or communal properties can present additional risks and responsibilities. Landlords, housing providers, and managing agents have a duty of care to ensure properties are safe and habitable.

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Unresolved mould can:

• Affect neighbouring units

• Lead to repeated tenant complaints

• Escalate into a more complex and costly remediation issue

• Early identification and professional handling of mould contamination can prevent long-term damage and protect occupants.

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Key Takeaway

 

Mould should never be dismissed as purely cosmetic when it is persistent, widespread, or affecting health. Understanding when mould becomes a biohazard is essential for protecting people and properties.

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This section is intended to provide clear, factual information to support informed decisions about mould contamination and environmental safety.