Humidity Happens, Mould Doesn't Have To

Understanding Damp, Mould, and Indoor Air Quality in Housing

Types and Causes of Damp

Part F Ventilation Regulations and Extractor Fan Performance

Causes and Prevention of Condensation

Damp in homes can arise from several sources, each requiring different solutions. The main types include:

· Penetrating Damp: Caused by water ingress through walls, roofs, or windows due to structural defects like broken gutters or missing roof tiles.

· Rising Damp: Occurs when moisture from the ground travels up through walls due to a failed or missing damp-proof course.

· Ground Damp: Similar to rising damp but often due to poor drainage or high water tables around the property.

· Condensation Damp: The most common type, caused by moist air condensing on cold surfaces, often due to inadequate ventilation or heating.

Causes and Prevention of Condensation

Part F Ventilation Regulations and Extractor Fan Performance

Causes and Prevention of Condensation

Condensation occurs when warm, moist air meets a cold surface, causing water droplets to form. Common activities that may increase humidity levels include:

• Cooking without lids or extractor fans

• Drying clothes indoors

• Inadequate ventilation in bathrooms and kitchens

• Poor insulation and cold surfaces

Mitigation strategies include:

• Using extractor fans during cooking and bathing

• Drying clothes outdoors or using vented tumble dryers where possible

• Maintaining consistent low-level heating to avoid cold surfaces

• Opening windows or using trickle vents to improve airflow

Part F Ventilation Regulations and Extractor Fan Performance

Approved Document F of the Building Regulations outlines the requirements for compliant ventilation in dwellings. Key points include:

• Bathrooms require extractor fans with a minimum intermittent extract rate of 15 litres/second.

• Kitchens require 30 l/s if adjacent to a hob or 60 l/s if not.

• Ventilation systems must be designed to ensure continuous airflow and avoid moisture build-up.

• Trickle vents and mechanical ventilation systems (e.g., MVHR) are recommended in airtight homes.

Advice for Tenants on Managing Condensation

Advice for Landlords on Responding to Condensation and Mould

Part F Ventilation Regulations and Extractor Fan Performance

Tenants can take steps to assist in lowering the amount of condensation produced:

• Ventilate rooms regularly by opening windows or using trickle vents.

• Use extractor fans when cooking or bathing.

• Avoid drying clothes indoors; if unavoidable, use a well-ventilated room.

• Keep furniture slightly away from external walls to allow airflow.

• Wipe down condensation on windows and cold surfaces daily.

Advice for Landlords on Responding to Condensation and Mould

Landlords have a legal duty to ensure properties are free from damp and mould.

Best practices include:

• Respond promptly to tenant reports of damp or mould.

• Inspect and repair structural defects (e.g., leaks, broken gutters).

• Install and maintain adequate extractor fans and trickle vents.

• Educate tenants on moisture management and provide guidance leaflets.

• Ensure heating systems are functional and insulation is adequate.

• Mitigate excessive condensation by way of additional HVAC or dehumidification.

Impact of Overcrowding on Indoor Air Quality

Advice for Landlords on Responding to Condensation and Mould

Overcrowding increases moisture production and reduces air circulation, leading to higher humidity and mould risk. Effects include:

• Increased CO2 and humidity from breathing and activities

• Greater wear and tear on ventilation systems

• Higher risk of condensation and mould in confined spaces

• Reduced sleep quality and increased stress

Health Risks of Damp and Mould

How Breathe Pure Supports Compliance and Prevention

Legal Responsibilities and Awaab’s Law

Exposure to damp and mould can lead to serious health issues, particularly for vulnerable groups. Risks include:

• Respiratory infections and asthma exacerbation

• Allergic reactions and skin irritation

• Increased risk of hospitalisation for children and elderly

• Mental health impacts due to poor living conditions

Legal Responsibilities and Awaab’s Law

How Breathe Pure Supports Compliance and Prevention

Legal Responsibilities and Awaab’s Law

Landlords must comply with several legal standards to ensure homes are safe and habitable:

• Housing Act 2004 and the Housing Health and Safety Rating System (HHSRS)

• Homes (Fitness for Human Habitation) Act 2018

• Landlord and Tenant Act 1985

• Awaab’s Law (from October 2025): Requires social landlords to investigate and resolve significant damp and mould hazards within strict timeframes (24 hours for emergency hazards, 10 days for significant damp/mould).

How Breathe Pure Supports Compliance and Prevention

Breathe Pure offers integrated solutions to tackle damp, mould, and indoor air quality issues:

• IW25-5 On Wall Dehumidifier with built-in ozone-free bipolar ionisation

• Actively reduces humidity below 60% RH to prevent mould growth

• Neutralises airborne mould spores and improves air quality

• Supports compliance with Awaab’s Law and HHSRS

• Low-maintenance, wall-mounted design suitable for social housing

• Reduces disrepair claims, mould wash costs, and improves tenant wellbeing