Airtightness

What is Airtightness?

Airtightness refers to a building’s ability to prevent the unwanted flow of air between its interior and exterior, achieved by installing effective airtightness barriers. This process focuses on minimising air leakage to retain conditioned indoor air and block uncontrolled outdoor air.

Internally, airtightness is achieved by sealing gaps, cracks, and joints in the building envelope, including walls, windows, doors, and roofs. Using high-quality insulation and sealing materials helps improve energy efficiency and thermal comfort by preventing air infiltration.

Externally, airtightness involves safeguarding the building envelope with weather-resistant barriers, such as cladding, and ensuring sealed penetrations to protect against wind, rain, and air leaks.

By incorporating airtightness barriers both inside and outside the structure, a building can significantly reduce energy consumption, lower carbon footprints, and provide a more comfortable, healthier living or working environment free from drafts and humidity issues.

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

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.

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.

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.

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