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Air Leaks and Draughts

Air leaks reduce the thermal performance of a building and the main culprits are openings and cracks in the building’s walls and roof.​

Air leaks can lead to excess moisture, which leads to mould and other health risks. It also has a host of other downsides and living in a building with air leaks is considered both dangerous and expensive. 

Air Flow and Building Design

Understanding airflow is essential for constructing a building that is comfortable and energy efficient.

Here are some key terms to know:

  • Exfiltration: Air that exits a building uncontrollably through cracks and other openings.
  • Infiltration: Air that enters a building through uncontrolled means.
  • Ventilation: The controlled movement of fresh air in and out of a building.

Builders aim to construct buildings with controlled ventilation to reduce air leaks and improve energy efficiency. This is particularly important with the demand for energy-efficient buildings within Australia.

Before finalising a development application, a Thermal Performance and Energy Efficiency Assessment is conducted to determine the most efficient building materials, orientation, design layout, window glazing, insulation, cross-ventilation and other specifications to ensure compliance with the National Contruction Code (NCC).

The Importance of Moisture Control and Mould Prevention

One of the primary consequences of air leaks is the accumulation of moisture on walls, which can lead to the formation of mold. This can have an immediate impact on those who reside within the building.

Air Leaks at Home

The Effects of Mould on Health

Inhaling mold fragments or spores can cause inflammation of the airways, resulting in nasal congestion, wheezing, chest tightness, coughing, and throat irritation. Prolonged exposure to high levels of indoor dampness can reduce lung function and lead to chronic health issues such as asthma.

Mycotoxins, which are present in some molds, can damage and kill neurons in the brain, affecting our mental capacity and psychological well-being. Neurological symptoms of mycotoxin ingestion include confusion, dizziness, a “foggy” brain, hallucinations, seizures, and trembling.

Other symptoms to watch out for, such as respiratory, circulatory, and other conditions, include difficulty breathing, bleeding gums, nosebleeds, cold and flu symptoms, vomiting blood, wounds that won’t heal, blurred vision, nausea, and jaundice. If you notice any of these symptoms, it’s essential to seek medical attention as the infection from damp and mold can be severe.

There’s also evidence that mycotoxins can cause cancer, highlighting the importance of mold prevention.

Overall, airtight buildings are not only better for your health, but they’re also more comfortable to live in and have a higher Thermal Performance Rating, making them far more energy-efficient than those with uncontrolled air leaks.

Identifying Common Causes of Air Leaks in Buildings

Air leaks can be very problematic for building owners, and it’s important to identify the root cause of each leak. Here are some common construction details that can lead to uncontrolled airflow:

Lack of Drywall

Buildings with dropped ceilings, angled staircase ceilings, and knee walls are often less airtight due to the absence of a plaster or drywall layer.

By paying attention to these factors, building owners can work to minimise air leaks and improve energy efficiency.

Insufficient Insulation Behind Skirting Boards

It’s not uncommon for areas behind skirting boards to lack proper insulation, which can lead to issues. While builders are typically responsible for addressing these concerns, homeowners can also take some effective measures to mitigate them.

Preventing Air Leaks in Garages

Garages are often more susceptible to air leaks, in particular, the foundation is a common source of cold air. While older homes may require significant modifications to address this issue, caulking gaps is an effective temporary solution. Additionally, garage doors can be weather-stripped to further prevent air leaks.

Recessed Lighting

Recessed lighting is a frequently used source of air leakage as each light requires individual insulation, which can be both time-consuming and costly. For new homes, it is recommended that alternative lighting positions be carefully considered.     Light choices   

The Impact of Wind on Air Leakage

The amount of air leakage can be significantly influenced by wind.  For example, on the windward side of the building, air infiltration occurs due to the higher-pressure zone created by the wind.  In contrast, the non-windward walls are exposed to lower pressure, which results in most of the exfiltration.

The best bet in either case is to seal any gaps and cracks on the walls’ surface. Below are some examples of how to do that.

Improving Energy Efficiency: Tips for Doors and Windows

Doors and windows are common culprits for temperature drops and draughts in your home. To combat this issue, homeowners can utilise weather-stripping on every door to seal the cracks.

Note that weather-stripping is also effective for windows with inadequate sealing, however; if you have unopenable windows, caulking may be more appropriate.

Older buildings may require a more comprehensive solution, including the reconstruction of doors and windows. Although it may be a lot of work, installing new doors and windows is the best solution.

For new buildings, choosing high-quality windows and doors that seal well is essential to avoid future regrets.

Pipes and Kitchen Units

Air leaks are common around sink pipes and soil pipes. Additionally, they can happen through the panel beside the sink, behind kitchen counters and/or behind appliances.

In short, leaks can be a problem anywhere there is pipe penetration.

At times, these gaps are an error in construction, but they can also be created later, in the case of plumbing repairs.

Fortunately, this type of air leak has a fairly straightforward solution. If the gaps are smaller than 1/4 inches across, it’s enough to caulk them. For homeowners, it’s usually best to use acrylic latex caulk, which is easy to apply even with little experience with household repairs.

In the case of larger gaps (up to 3 inches), soft foam is necessary, which is another affordable and easy-to-use tool.

Electric Cables and Fittings

Electricians, like plumbers, can also leave gaps through drywall.

Fortunately, you can tackle this issue yourself with the right tools and materials. Begin by identifying all the draughts around electric fittings and other installations.

From there, apply caulking to fill in the gaps. It’s a simple solution that doesn’t require expert assistance.

Window Installation