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Weatherproofing of masonry has been a crucial aspect of construction for decades, with historical houses built 1950 and earlier serving as a testament to its importance. Observing the prevalence of weepholes and brick air vents in these older structures, it becomes evident that proper weatherproofing measures have long been recognised as vital for ensuring the health and longevity of buildings. However, despite the significance of weatherproofing, Part 5.7 'Weatherproofing of Masonry' in the National Construction Code (NCC) is frequently overlooked or neglected during construction, leading to a range of issues such as rising damp and moisture-related problems in dwellings.

Part 5.7 in the NCC plays a crucial role in safeguarding the health and integrity of masonry buildings. Unfortunately, many modern constructions tend to overlook or neglect the implementation of weatherproofing measures outlined in this code. Consequently, buildings suffer from rising damp and moisture-related complications that can compromise structural integrity and create unhealthy living conditions for occupants. Conspar is often called out to review and remedy such issues.

This article delves into the significance of Part 5.7 'Weatherproofing of Masonry' in the NCC and sheds light on the essential requirements for effective weatherproofing. Specifically, we explore the importance of weepholes and air vents. By understanding and prioritising weatherproofing measures, construction practices can be improved, resulting in healthier and more durable buildings that stand the test of time.


When the guidelines and regulations outlined in the fact sheet for Part 5.7 Weatherproofing of Masonry are not followed, several negative consequences can arise, impacting the structural integrity, safety, and longevity of the building. Here are some potential issues that may occur:

  1. Water Infiltration: Failure to maintain proper cavities, damp-proof courses, and flashings can lead to water infiltration through the masonry walls. This water ingress may cause moisture-related problems, such as mould growth, rotting of structural components, and damage to interior finishes.

  2. Material Deterioration: Masonry materials are susceptible to deterioration when exposed to prolonged moisture. Without adequate weatherproofing measures, the masonry may weaken, spall, or crack over time, compromising the building's stability.

  3. Structural Damage: Water infiltration can erode mortar joints and weaken the bonds between masonry units, resulting in structural instability. Over time, this can lead to significant structural damage, posing safety risks to occupants and requiring costly repairs.

  4. Energy Inefficiency: Poor weatherproofing can contribute to air leakage and heat transfer through the walls, leading to energy inefficiency. This can result in higher energy bills as the building's heating and cooling systems work harder to maintain comfortable temperatures.

  5. Aesthetic Problems: Water stains, discolouration, and efflorescence (salt deposits) may appear on the masonry surface when water is allowed to penetrate the walls. These aesthetic issues can negatively impact the building's appearance and reduce its overall value.

  6. Termites and Pests: Inadequate weatherproofing can create entry points for pests, including termites, rodents, and insects. These pests can cause further damage to the structure and compromise the building's integrity.

  7. Non-compliance and Legal Issues: Building codes and regulations often mandate proper weatherproofing measures to ensure safety and quality standards. Failure to comply with these requirements may result in legal issues, fines, or the need for costly corrective actions.

  8. Early Degradation: Without proper weatherproofing, the masonry may experience premature degradation, reducing the expected lifespan of the building and necessitating premature renovations or replacements.

THE HEALTH IMPLICATIONS When weatherproofing of masonry is not properly implemented, it can lead to several health-related problems for building occupants. These issues are often associated with moisture intrusion and the growth of mold and mildew. Here are some health problems that can arise:

  1. Respiratory Issues: Mould and mildew thrive in damp environments, and when they grow within the building's walls or on surfaces, they release spores into the air. Inhaling these spores can trigger respiratory problems, especially in individuals with allergies or asthma. Symptoms may include coughing, wheezing, shortness of breath, and throat irritation.

  2. Allergic Reactions: Exposure to mould spores and other indoor allergens can cause allergic reactions in some people. Common allergic responses include sneezing, runny or stuffy nose, itchy or watery eyes, and skin rashes.

  3. Asthma Exacerbation: For individuals with asthma, mould exposure can worsen their symptoms and lead to asthma attacks. Mould spores can trigger inflammation in the airways, making it more difficult to breathe.

  4. Infections: In some cases, certain types of mould can produce mycotoxins that may cause infections if inhaled or come into contact with open wounds or compromised skin.

  5. Sick Building Syndrome: Prolonged exposure to indoor air pollution caused by mould and other contaminants can lead to a condition known as Sick Building Syndrome (SBS). Symptoms of SBS may include headaches, dizziness, fatigue, nausea, and difficulty concentrating.

  6. Immune System Suppression: Prolonged exposure to mould and other indoor pollutants may weaken the immune system, making individuals more susceptible to infections and illnesses.

  7. Skin Irritation: Mould and moisture can also lead to skin irritation or exacerbate existing skin conditions, especially if individuals come into direct contact with affected surfaces.

It's essential to address weatherproofing issues promptly and conduct proper remediation if mould or moisture-related problems are detected in a building. This includes repairing leaks, improving ventilation, and using appropriate materials and construction techniques to prevent water infiltration and mould growth.

In addition to the health risks, poorly weatherproofed masonry can also lead to structural problems, as mentioned in the previous response. Addressing both structural and health-related concerns is crucial to maintaining a safe, comfortable, and healthy living or working environment. Regular inspections and maintenance are vital to identify and address weatherproofing issues before they escalate and cause significant problems.


If homeowners feel that their home is lacking in some or all of the aspects of Part 5.7 'Weatherproofing of Masonry', there are several steps they can take to address the issue and improve the weatherproofing of their property:

  1. Inspect the Property: Conduct a thorough inspection of the home, both inside and outside, to identify any potential weatherproofing deficiencies. Look for signs of moisture infiltration, such as water stains, mould growth, or dampness on walls and ceilings.

  2. Consult Professionals: Seek advice from qualified professionals, such as building inspectors, architects, or experienced contractors, who can assess the weatherproofing condition of the property and suggest appropriate solutions.

  3. Repair or Replace Damaged Components: If any components related to weatherproofing, such as weepholes, flashings, or damp-proof courses, are damaged or missing, arrange for their repair or replacement promptly to prevent further issues.

  4. Install Proper Weepholes and Flashings: If the property lacks proper weepholes and flashings, consider installing them around the full perimeter of the masonry building and above any openings wider than 1.2 meters. Ensure that the weepholes are appropriately spaced and installed to allow proper drainage.

  5. Improve Ventilation: Good ventilation is crucial for preventing moisture buildup. Ensure that the property has adequate ventilation in areas such as the kitchen, bathroom, and laundry, as well as in the attic or crawl spaces.

  6. Seal Cracks and Gaps: Seal any cracks or gaps in the masonry walls to prevent water intrusion. Use appropriate sealants and materials to ensure effective weatherproofing.

  7. Consider External Coatings: Explore the option of applying external coatings, such as water repellents or waterproof coatings, to enhance the weatherproofing of the masonry walls.

  8. Manage Landscaping: Ensure that the landscaping around the property encourages proper drainage away from the masonry walls. Avoid allowing water to accumulate near the foundation.

  9. Monitor and Maintain: Regularly monitor the property for any signs of weatherproofing issues and conduct routine maintenance to address any emerging problems promptly.

  10. Seek Professional Weatherproofing Services: If the task seems complex or beyond your expertise, consider hiring professionals with experience in weatherproofing to ensure that the job is done correctly and effectively.

Improving the weatherproofing of a home is crucial for the long-term health and durability of the property. By taking proactive steps and investing in appropriate weatherproofing measures, homeowners can create a safer, healthier, and more comfortable living environment for themselves and their families. HOW TO

If you are interested in finding out more about what is involved in retrofitting weepholes or air vents into your building, click here for our guide.

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