Airtightness

What is Airtightness?

Airtightness refers to the ability of a structure to prevent the unwanted flow of air between its internal and external environments. It involves designing and constructing buildings to minimise air leakage, ensuring that conditioned indoor air remains inside while preventing the entry of uncontrolled outdoor air.

Internally, airtightness is achieved through careful attention to the building envelope, including walls, windows, doors, roofs, and other components. Sealing joints, using insulation materials, and addressing gaps and cracks help prevent air infiltration, improving energy efficiency and thermal comfort.

Externally, airtightness involves protecting the building envelope from external elements like wind and rain. Properly installed cladding and weather-resistant barriers, along with sealed penetrations, ensure that air infiltration is minimised, maintaining the desired indoor environment.

Overall, achieving airtightness in building construction requires a comprehensive approach that considers both internal and external factors. It improves energy efficiency, reduces carbon footprint, and provides a healthier and more comfortable living or working environment by minimising drafts and controlling humidity levels.

Benefits of Airtightness

1. Reduced heating costs

When properly installed, the Airstop system saves energy and can dramtically reduce your heating costs. Warm air is not allowed escape through gaps and cold air is not allowed to blow into your home, resulting in:

• Substantial ongoing savings in heating costs
• Reducing of your carbon footprint
• Improving the energy rating of your home
• Increasing future resale of your home
• Protecting your home against condensation

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2. Improved comfort

In the absence of an airtight envelope, cold air coming in through unsealed points is heavier than the warm air in your house. This cold air falls to the lowest point in the room – the floor. Cold floors result in cold feet, no matter how effective your heating system.

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3. Outperform Building regulations

In July 2008 the new Part L Building regulations came into effect. These new regulations introduced specific airtightness requirements for the first time. This requirement translates to an air permeability rate of 10m3/(hr.m2) at 50 pascals. Compliance to these standards will be measured by air pressurisation tests known as the Blower Door Test.

The Airstop system has a proven track record in some of the harshest climates in Europe but more importantly, our system is used where the level of air permeability required is far more exactly. The Airstop system is often used in projects where the minimum requirement is 3m3/(hr.m2) at 50 pascals. Furthermore, other energy saving systems such as heat recovery units, operate far more effectively in conjunction with an airtight system.

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4. Improved Air Quality

Draughts through internal walls are not beneficial to the atmosphere in your home, as dust and insulation fibres can be circulated. The Airstop airtight system ensures any dust and fibres remain in your wall cavity and do not escape into the atmosphere in your house.

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5. Protect from condensation

When using the Airstop vapour control barrier, your house can breathe and moisture in the air can pass through your walls and evaporate.

Dangers of uncontrolled condensation:

• Deterioration in the U-value of your insulation
• Build up of mould, mildew & fungus that can lead to health problems
• Structural damage due to rotting timber