Waterproofing is one of the most important parts of any concrete structure, yet it’s also one of the most common points of failure. When waterproofing does not perform as intended, the results can be costly: leaks, corrosion, structural damage, and expensive remediation.
Through our work with engineers, asset owners, builders, and contractors across Australia, we’ve seen that many of these problems come from preventable causes. The good news is that with the right knowledge and materials, most waterproofing failures can be avoided before they begin.
This article highlights five of the most common waterproofing problems in concrete and explains how to prevent them using proven, long-term solutions.
Concrete is naturally porous, which means water can move through tiny capillaries and cracks if the waterproofing system is not applied or designed correctly. Most waterproofing failures happen because of poor installation quality, poor product selection, or design oversights rather than product defects.
Common causes include poor surface preparation, incorrect application methods, and using incompatible materials. Structural movement, cracking, and drainage issues can also contribute to failure over time.
Understanding why waterproofing fails is the first step in preventing it.
Waterproofing success begins with how well the surface is prepared. When concrete surfaces are dirty, uneven, or contaminated, the waterproofing product cannot bond properly. Common issues include dust, laitance, oil residue, curing compounds, and moisture trapped in the substrate. These problems prevent coatings or membranes from adhering and create weak spots that allow water to seep through.
To avoid this, ensure the surface is clean, dry, and structurally sound before applying any waterproofing material. Conduct moisture testing, remove laitance, and follow the manufacturer’s surface preparation guidelines. A properly prepared surface gives the waterproofing system the best chance to perform long-term.
Penetron products go a step further by working within the concrete itself. Our crystalline technology forms an internal barrier that seals microcracks and capillaries, eliminating the need for surface adhesion and reducing the risk of failure.
Even the best waterproofing materials can fail if they’re applied incorrectly. Uneven coating thickness, missed areas, and poor curing are some of the most common mistakes made on-site. These errors often happen when installers rush the job or skip key steps in the manufacturer’s instructions.
Incorrect application can leave gaps in coverage, creating weak points that allow moisture to enter. Over time, this leads to peeling, blistering, or full system failure.
To prevent this, use trained installers and follow the exact application guidelines for each product. Pay attention to curing times, temperature, and humidity conditions during installation. Consistent supervision and quality checks at every stage are essential for long-term performance.
At Penetron, our products are supported by a network of certified applicators and technical specialists who ensure every system is installed correctly. This partnership helps reduce the risk of failure and ensures reliable, lasting waterproofing results.
Concrete naturally expands, contracts, and settles over time. These movements can cause cracking, which allows water to travel through the structure. Even small cracks are enough to compromise waterproofing if the system cannot adapt or self-seal.
Common causes include temperature changes, shrinkage during curing, heavy loads, and ground movement. Traditional membrane systems often fail in these situations because they rely on surface adhesion and cannot respond to ongoing structural movement.
The most effective way to prevent water ingress is to make waterproofing an integral part of the concrete itself. When the protection is within the concrete matrix, cracks are less likely to lead to leaks.
Penetron’s crystalline technology activates in the presence of moisture to seal cracks up to 0.5 mm, even long after the concrete has cured. This self-healing ability helps maintain long-term waterproofing performance and reduces the need for costly repairs.
Waterproofing often fails when multiple products or systems are used without checking compatibility. Some materials react poorly when combined, leading to separation, blistering, or chemical degradation. For example, applying a coating over a membrane that doesn’t bond correctly can cause the entire system to delaminate.
Inconsistent performance also occurs when contractors mix products from different suppliers without confirming how they interact. These mismatched systems can leave gaps in protection, creating weak points where water can enter.
To avoid this, always use products that are designed to work together as part of a single, integrated waterproofing system. Follow the supplier’s technical data sheets and confirm compatibility before installation.
Penetron simplifies this process by providing a complete waterproofing system, from admixtures to surface treatments, all engineered to perform as one cohesive solution. This ensures reliability, consistency, and long-term protection for every project.
Even the best waterproofing system can fail if the structure’s design does not manage water effectively. Poor drainage, inadequate falls, or missing weep holes can cause water to pool against the surface. Over time, this builds hydrostatic pressure that forces moisture through cracks and joints.
Design oversights such as poorly placed joints, insufficient waterproofing coverage, or incorrect detailing at transitions are also common causes of failure. These issues often arise when waterproofing is considered too late in the design or construction process.
To prevent this, waterproofing should be planned early and integrated into the overall design. Proper slopes, joint detailing, and drainage systems are essential to direct water away from the structure and reduce pressure on the waterproofing layer.
Penetron works closely with engineers and builders during the design phase to identify potential risks and specify solutions that prevent future problems. Our technical support team provides detailed advice and on-site guidance to help ensure every project achieves a watertight result.
Most waterproofing failures can be prevented with the right planning, materials, and execution. The key is to treat waterproofing as part of the concrete structure, not just a surface coating. When the waterproofing system works from within, the protection becomes permanent, and maintenance requirements drop significantly.
To ensure lasting performance:
Penetron’s crystalline technology provides a permanent solution by turning concrete into its own barrier against water and chemical ingress. Our team supports every stage of the project, from design and specification to on-site implementation, ensuring every structure stays protected for decades.
For expert advice or to discuss your next project, contact Penetron Australia today. Our team can help you specify the right system and avoid common waterproofing problems before they occur.
Every waterproofing method has trade-offs, and cementitious systems are no exception. They are widely used because they are simple, reliable, and cost-effective, but they also have clear limits.
By looking at both the advantages and disadvantages, you can see where cementitious waterproofing delivers strong results and where another approach might be better. This balanced view makes it easier to choose the right solution for your project.
The products are mixed with water or a liquid additive and applied with a brush, roller, trowel, or spray. This makes them easier to use than membranes or multi-layer systems.
Cementitious coatings form a solid bond with concrete and masonry, ensuring long-term stability without peeling or blistering.
Effective against both positive and negative water pressure, protecting structures exposed to groundwater or stored water.
Provides reliable waterproofing at a relatively low material and labour cost, making it appealing for large projects.
VOC-free, non-toxic, and suitable for potable water applications such as drinking water tanks and reservoirs.
Because it is cement-based, it integrates naturally with concrete and maintains the same thermal expansion rate, reducing stress on the structure.
Suitable for basements, foundations, wet rooms, tunnels, bridges, swimming pools, and water tanks.
Once cured, coatings require little upkeep, especially in sheltered areas not exposed to direct sunlight or harsh chemicals.
Used globally in residential, commercial, and infrastructure projects, with decades of performance history.
Cementitious coatings are rigid. They may crack if the substrate moves or vibrates, which makes them less effective on dynamic structures.
Surfaces must be cleaned and repaired before application. Any dust, oil, or loose particles can prevent proper bonding.
The coating needs time to harden and cure. If curing is rushed or skipped, the waterproofing layer can weaken and fail.
Expansion joints, suspended slabs, or structures exposed to regular vibration are better suited to flexible systems like liquid membranes.
Exposure to aggressive chemicals, high abrasion, or strong UV light can shorten the life of cementitious coatings.
If applied too thin, the coating may not resist water pressure. Skilled application is needed for best results.
Cementitious finishes are plain and functional. They are usually hidden behind finishes or left in non-visible areas.
In harsh environments, reapplication or repair may be needed to maintain performance.
Cementitious waterproofing is best suited for projects where the structure is stable and not subject to frequent movement. It works well in below-ground and water-retaining applications, where durability and cost efficiency are more important than flexibility.
This makes it a strong option for:
For structures that move, expand, or face harsh chemical exposure, a more flexible system like liquid membranes or advanced crystalline products may be the better choice.
Cementitious waterproofing is a simple and reliable way to protect concrete and masonry from water damage. It uses a cement-based coating that bonds strongly to surfaces, creating a barrier against moisture and pressure.
This method is widely used in basements, water tanks, bathrooms, and large structures like bridges and tunnels. Builders and engineers value it for its durability, ease of application, and cost efficiency.
If you need long-term protection against water intrusion, cementitious waterproofing offers a proven solution that works across residential, commercial, and infrastructure projects.
Cementitious waterproofing is a method that uses a cement-based coating to stop water from passing through concrete and masonry. The coating is mixed with special additives that improve strength, flexibility, and resistance to water pressure.
Once applied, the coating hardens to form a protective layer that bonds to the surface. This layer blocks moisture from entering the structure while still allowing the surface to breathe. Because it uses cement as the base, it integrates well with concrete and delivers reliable performance over time.
Cementitious waterproofing is common in both residential and commercial projects. It is often applied in areas that face constant moisture or water pressure. Typical uses include:
Method | Key Features | Limitations | Best Use Cases |
Cementitious | Cement-based coating, easy to apply, cost-effective | Less flexible than membranes | Basements, tanks, bathrooms, infrastructure |
Liquid Membranes | Flexible, seamless finish | Higher cost, skilled application needed | Roofs, podium decks, complex surfaces |
Bituminous Coatings | Good adhesion, resistant to moisture | Degrades under UV exposure | Foundations, areas not exposed to sunlight |
Crystalline Systems | Self-healing, penetrates concrete | Higher cost, more specialised | Long-term protection in critical structures |
Cementitious waterproofing stands out as a practical, affordable option when you need reliable waterproofing without complex installation.
Our cementitious waterproofing products:
Cementitious waterproofing is reliable, but it is not always the best fit for every situation. Its rigid nature means it can crack if the structure moves or shifts. This makes it less suitable for buildings exposed to high vibration or frequent structural changes.
The surface must also be properly prepared before application. Any dust, oil, or uneven areas can weaken the bond and reduce effectiveness. In environments with high water pressure or chemical exposure, the coating may wear down over time and require maintenance.
Another drawback is its limited resistance to prolonged sunlight and weathering. For this reason, it is most effective in internal areas or places protected from direct exposure.
When applied correctly, cementitious coatings and mortars can last for decades. They bond with concrete and resist water pressure, providing long-term protection with minimal maintenance.
Yes. Products like Penetron’s cementitious systems are VOC-free and non-toxic, making them safe for use in homes, commercial buildings, and water storage structures.
Penetron Australia offers a full range of cementitious solutions. Each product is tested to Australian standards and proven in demanding conditions.
Yes. With proper surface preparation, cementitious coatings and mortars bond well to existing concrete and masonry. They are often used in repair and remediation projects.
The surface is cleaned and repaired first. The product is then mixed and applied as a slurry, mortar, or plug, depending on the product type. Application can be done with a brush, roller, trowel, or spray.
Yes. These products perform well in conditions with continuous water exposure, such as water tanks, pools, and basements.
Positive-side waterproofing is applied to the surface in direct contact with water (e.g., the outside of a tank). Negative-side application is applied to the opposite surface, stopping water from entering interior spaces. Cementitious products can often handle both.
Waterproofing is a critical part of any construction project. Done properly, it protects buildings from water damage, extends the life of the structure, and reduces long-term repair costs. But in Australia, it’s not just about protection, it’s about meeting strict building standards.
The National Construction Code (NCC) and relevant Australian Standards, such as AS 3740 and AS 4654.2, set out clear waterproofing requirements for both residential and commercial buildings. These aren’t suggestions, they’re legal obligations. Failing to comply can lead to costly rectification work, insurance issues, and safety concerns.
Builders, engineers, and contractors need to ensure that every waterproofing system used is tested, approved, and applied correctly. That means using the right products, following the right methods, and working with experienced professionals who understand the standards inside and out.
Waterproofing in Australia must comply with the National Construction Code (NCC) and relevant Australian Standards. These documents define how waterproofing should be designed, installed, and tested to ensure long-term performance.
The two main standards are:
AS 3740:2021 – Waterproofing of Domestic Wet Areas
This standard applies to internal wet areas such as bathrooms, laundries, and toilets. It outlines the correct installation of waterproofing membranes, floor gradients, and wall junctions to prevent water ingress.
AS 4654.2:2012 – Waterproofing Membranes for External Above-Ground Use
This applies to balconies, rooftops, podiums, and other above-ground structures. It specifies performance requirements for external membranes, including UV resistance, durability, and bond strength.
Together with the NCC, these standards form the legal baseline for waterproofing in construction. Builders, engineers, and waterproofers must ensure that all materials and methods used meet or exceed these requirements.
These standards apply across residential, commercial, and infrastructure projects. Meeting them is not optional, it’s essential for certification, insurance, and long-term structural protection.
Compliant waterproofing isn’t just about following rules, it protects your project, your reputation, and your bottom line.
Here’s why it matters:
Legal Requirements
The NCC and Australian Standards are enforceable. If waterproofing doesn’t comply, you risk building approval delays, fines, or legal action.
Structural Integrity
Water damage weakens concrete, corrodes steel, and leads to cracks, mould, and deterioration. Proper waterproofing prevents long-term structural issues.
Cost Avoidance
Non-compliant work often needs to be redone, sometimes after the structure is complete. Fixing failed waterproofing can cost more than doing it right the first time.
Insurance and Warranty Issues
Many insurance providers require proof of compliance. If waterproofing doesn’t meet the standard, claims may be rejected, and warranties can become void.
Project Reputation
Poor waterproofing can delay handovers and damage trust with clients. Consistently meeting standards shows professionalism and reliability.
Waterproofing compliance is a shared responsibility. Each party involved in the project plays a role in meeting Australian building standards.
Builders and Site Supervisors
Responsible for coordinating trades, checking that waterproofing is correctly installed, and ensuring products used are compliant.
Waterproofing Contractors
Must apply membranes and systems according to manufacturer guidelines and Australian Standards. Licensing and training are essential.
Engineers and Architects
Specify waterproofing systems that meet project needs and comply with the NCC and AS standards. They also assess compatibility with other structural elements.
Certifiers and Building Surveyors
Inspect and sign off on completed work. They require evidence that all waterproofing meets code.
Product Suppliers and Manufacturers
Have a duty to provide certified systems backed by testing, technical documentation, and application guidance.
Not all waterproofing systems meet Australian standards. Choosing the right product is essential to ensure compliance, performance, and durability.
Here’s what to look for:
Certified to AS Standards
Products should be tested and verified to meet AS 3740 (internal wet areas) or AS 4654.2 (external membranes), depending on the application.
Compatible With Concrete and Substrates
Ensure the product bonds effectively with the specific materials used on-site, including precast, cast-in-place, and high-performance concrete.
Backed by Technical Documentation
The system should come with data sheets, application guidelines, test results, and compliance statements. This supports design, installation, and certification.
Proven in Australian Conditions
Products should withstand local climate extremes – heat, humidity, rain, and UV exposure, without failure or breakdown.
Supported by Industry Experts
Look for suppliers who offer technical advice and ongoing support, from planning to final inspection.
Penetron waterproofing systems are engineered to meet these requirements. Our solutions are certified, high-performing, and trusted by builders and engineers across Australia.
Penetron Australia provides concrete waterproofing systems that are trusted for their performance and compliance. Our products are engineered for Australian conditions and meet the requirements of the National Construction Code and relevant Australian Standards.
Here’s how we support compliance on every project:
Certified Waterproofing Solutions
Our products are tested to AS 3740 and AS 4654.2 standards and come with full technical documentation to support specification and certification.
Expert Technical Support
Our team works closely with engineers, architects, and contractors to recommend the right solution based on your design and compliance needs.
Proven Track Record
Penetron products have been used in major infrastructure, commercial, and residential projects across Australia. Our experience spans over 18 years in the local market.
Ongoing Product Development
We continue to improve and test our systems to stay ahead of changes in standards and building codes.
With Penetron, you’re not just getting a product, you’re partnering with a team that understands the compliance requirements and supports you at every stage of the build.
Before you start waterproofing, use this checklist to reduce risk and ensure your project meets Australian standards:
✔️ Use certified products tested to AS 3740 or AS 4654.2
✔️ Engage qualified waterproofing contractors with the right licences and experience
✔️ Follow the manufacturer’s installation guidelines without shortcuts
✔️ Document all work and product details for inspection and certification
✔️ Ensure compatibility between waterproofing systems and surrounding materials
✔️ Consult with your engineer or certifier if unsure about specifications
✔️ Keep up to date with changes to the NCC and Australian Standards
Waterproofing compliance isn’t optional – it’s essential for project success. Whether you’re planning a large-scale development or a small residential build, Penetron Australia can help you get it right.
Our certified waterproofing systems, expert support, and industry knowledge give you the confidence to move forward with certainty. We work with builders, engineers, and contractors across Australia to deliver compliant, long-lasting solutions that perform.
Get in touch with our team to discuss your project requirements and find the right waterproofing system for your needs.
Concrete is strong, but it is not immune to damage. Without protection, it can crack, erode, or allow water to seep through. This can lead to structural issues, high repair costs, and shorter lifespans for buildings and infrastructure. Knowing how to protect concrete is essential for long-term durability.
Concrete faces daily exposure to water, chemicals, temperature changes, and physical stress. These conditions can lead to:
Protecting concrete early prevents long-term problems and increases performance in harsh environments.
Several factors influence how long concrete lasts:
Surface sealers act as barriers. They prevent water and chemicals from entering the concrete.
Common types include:
These products require reapplication over time and are best for short to medium-term protection.
Crystalline technology protects concrete from within. It forms microscopic crystals that block water pathways when moisture is present.
Benefits:
Protects from both positive and negative water pressure
Protection starts during construction. Best practices include:
These steps help minimise future water intrusion and material stress.
Even well-protected concrete requires periodic checks. Look for:
Addressing issues early prevents deeper problems and costly repairs.
Concrete protection is essential for:
Each use case benefits from a different protection method depending on risk and function.
Penetron offers a range of solutions that protect concrete internally. Our products are used in infrastructure, commercial buildings, and water facilities across Australasia.
Professionals rely on Penetron for:
Knowing how to protect concrete is critical to extending its service life and performance. Whether for new construction or restoration, the right system can prevent damage and reduce costs.
Need a proven concrete protection method for your project? Contact Penetron for technical guidance and long-term performance.
Yes. Expansion joints allow the concrete to move without cracking under stress. Even when protected, these joints are critical to managing thermal movement and load changes.
Yes. Older concrete can be treated using repair mortars with crystalline additives or surface-applied systems that reactivate in the presence of moisture. This helps seal cracks and stop leaks.
Saltwater exposure increases chloride penetration, which corrodes steel reinforcement. Wind-driven moisture and sand abrasion also contribute to faster surface wear.
Some crystalline waterproofing products, including Penetron systems, are certified safe for use in potable water tanks and treatment facilities. Always check product certifications.
Yes. Quality treatments reduce water absorption, which helps prevent freeze-thaw damage. Crystalline systems are effective in both cold and humid environments.
Concrete is one of the most widely used construction materials due to its strength and versatility, but it has one significant vulnerability—it is porous. This means that water and other liquids can seep through its surface, potentially causing damage over time. So, can you waterproof concrete? The answer is yes, and doing so is critical for maintaining its durability and structural integrity.
Waterproofing concrete helps protect it from issues like cracking, spalling, and water ingress, which can weaken the material and compromise the structure’s safety. Whether you’re working on a basement, retaining wall, or swimming pool, understanding how to make concrete waterproof is essential for prolonging its lifespan and ensuring its performance.
Despite its strength and versatility, concrete is naturally porous. This means it contains tiny capillaries and voids that allow water and moisture to seep through. Over time, this permeability can lead to significant issues, especially in structures exposed to water or high humidity. Waterproofing is essential to protect concrete from these vulnerabilities.
Unprotected concrete is vulnerable to water ingress, which can compromise its structural integrity. When water seeps into the concrete, it can cause embedded steel reinforcement to corrode, leading to cracks and spalling. Freeze-thaw cycles can further worsen these problems as trapped water expands upon freezing, increasing stress on the material.
Beyond structural concerns, water penetration can lead to aesthetic damage like discolouration and encourage mould and mildew growth in adjacent areas. Therefore, waterproofing concrete is not just about durability—it also plays a role in maintaining the overall safety and appearance of the structure. Whether for foundations, retaining walls, or other critical elements, understanding how to make concrete waterproof is a key step in construction and maintenance.
Sealing concrete is an effective method to protect it from water damage. The process starts with cleaning the surface to remove dirt, debris, and oils that may interfere with adhesion. Once clean and dry, the sealer is applied evenly using a roller, brush, or sprayer, ensuring full coverage. Some sealers may require multiple coats, with proper drying time between applications.
Curing is crucial for the sealer to bond with the concrete and form a protective layer. Always follow the product’s instructions for curing times and environmental conditions. Proper sealing enhances water resistance and extends the lifespan of concrete surfaces like driveways, patios, and walls.
Concrete waterproofing is possible and essential for protecting structures from water damage and ensuring their long-term durability. Whether achieved through admixtures, crystalline technology, or surface sealers, waterproofing concrete helps prevent cracks, spalling, and other forms of structural degradation caused by moisture.
Incorporating waterproofing during construction provides a proactive solution, while retrofitting existing structures with effective methods can restore and protect their integrity. By taking the right steps to waterproof concrete, you guard your investment and enhance the lifespan of your structure. With the knowledge and tools available, waterproofing concrete is a practical and achievable goal for any project.
Concrete is one of the most durable and widely used construction materials, known for its strength and versatility. However, over time, cracks can develop due to various factors, from natural shrinkage in a concrete slab, to hairline cracks in exposed concrete surfaces. These cracks are not just cosmetic problems, left unaddressed they can lead to serious structural issues. Water ingress can weaken the concrete and exacerbate damage, especially under vehicle traffic, leading to costly repairs in the future.
Repairing cracks requires using an appropriate repair compound or concrete crack filler to maintain structural integrity. Below is a comprehensive overview of crack causes, repair methods, and tips for durable results.
Concrete is a resilient material that is not immune to cracking. Understanding why cracks form is the first step in addressing them effectively and preventing further damage. Here are some of the most common causes of concrete cracks:
As concrete sets and hardens, it naturally loses moisture. This process, known as curing, can cause shrinkage, leading to small hairline cracks on the surface. These cracks are often superficial but should still be monitored and addressed if they grow.
Concrete is designed to bear significant loads, but excessive weight or uneven settling of the ground beneath can lead to cracks. Over time, stress from heavy vehicles, machinery, or even normal use in areas like concrete driveways and car parks can weaken the material and cause fractures.
Temperature fluctuations, freezing and thawing cycles in exposed concrete surfaces, and exposure to water can all contribute to cracking. In colder climates, water that seeps into concrete can freeze, expand, and create pressure that results in cracks.
Cracks may also occur due to improper mixing, inadequate reinforcement, or insufficient curing time during construction. Ensuring high-quality workmanship is key to minimising the likelihood of cracks.
Understanding what caused the crack in the first place is critical. Whether it’s due to shrinkage, load stress, or environmental factors, addressing the root cause helps prevent future cracking.
Not all cracks are the same, and neither are the repair materials. Small, surface-level cracks may only require sealers, crack fillers or repair compounds, while deeper structural cracks need more robust solutions like epoxy injections or crystalline products. Always choose materials that match the specific requirements of the crack.
Cleanliness is crucial for a successful repair. Before applying the repair material, ensure the crack is free of debris, dust, and contaminants. A clean surface allows the product to adhere better and perform as intended.
Each repair product has unique application guidelines, including mixing ratios, application methods, and curing times. Following these instructions ensures the material performs to its full potential.
Curing is a critical step that should not be rushed. Allowing the repair material to set and harden as recommended by the manufacturer ensures a durable and long-lasting repair.
Preventing cracks in concrete begins with proper construction practices and ongoing maintenance. Achieving a durable mix requires the right balance of water, cement, and aggregates during preparation. Slow, controlled curing is also essential, allowing the concrete to strengthen while minimising the risk of shrinkage cracks.
Using high-quality materials, such as crystalline waterproofing admixtures, can significantly enhance the concrete’s resistance to water ingress and environmental stress. Reinforcing areas prone to heavy loads or ground movement and planning control joints to accommodate natural movement can further reduce the likelihood of cracking.
Protecting concrete from environmental stress through sealers or coatings and conducting regular inspections helps identify and address minor issues before they escalate. A proactive approach to maintenance is key to ensuring the longevity and integrity of your concrete structures.
Repairing cracks in concrete is an essential step in preserving the integrity and safety of structures. Whether the cracks are minor surface issues or signs of deeper structural concerns, addressing them promptly and effectively can prevent further damage and costly repairs. By understanding the causes of cracks, selecting the appropriate repair methods, and following best practices, you can ensure a durable and reliable fix.
While prevention is always better than repair, cracks can still occur even with the best practices. Having access to high-quality materials and expert guidance makes all the difference. If you’re unsure how to fix cracks in concrete or need assistance with a specific project, seeking advice from experienced professionals can help you achieve the best results. With the right approach and tools, concrete can remain strong and resilient for years to come.
