The Best NZ Guide -Water & Flood Proofing

In flood-prone New Zealand, property protection is crucial. Hurricane Gabrielle left homes debating whether to rebuild. Abandoning beachfront property is only possible whether it’s a tourist attraction, farming, or beloved home. It’s crucial to prepare your home for water damage.

Waterproofing protects your property from water damage. Regular roof, gutter, downspout, and foundation inspection and repair are essential. Emergency preparations and flood-resistant constructions are also vital safeguards.

New Zealand’s flood management laws have evolved since 1908, with no uniform law. Central and local governments play a role in managing flood risks.

Waterproofing and flood protection are crucial in the country, as water damage can lead to mould, mildew, and other issues.

Key legislation for flood risk management includes the Resource Management Act 1991 and Civil Defence Emergency Management Act 2002. Strategies for flood risk management include preventive decision-making, flexibility, and prioritizing no-regret and low-regret options.

Despite the climate change debate, floods have been very common in New Zealand making it crucial to find adaptable solutions.

Waterproofing, maintenance, and flood mitigation are needed to prevent water damage. You can safeguard your home against flooding by taking preventive steps.

The Destructive Power of Floods: Learning from New Zealand’s History

New Zealand has been affected by flood devastation for years. It has destroyed homes, infrastructure, natural resources, and people. Waterproofing and enhanced building flood solutions are necessary to prevent such severe results. A Māori tale of the enormous deluge and New Zealand’s flood history highlights the need for better architecture and infrastructure to survive nature.

Floods in NZ
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Tāwhaki, the thunder and lightning deity in Māori mythology, was nearly killed by his brothers-in-law. He recovered and erected a fortified village with his soldiers and their family on a mountaintop. He begged punishment from the gods, who caused the sky to flood, drowning Mataaho’s residents. This myth warns of floods’ destructive power and the need to prepare.

Recent floods in New Zealand include Cyclone Bola’s devastation of Hawke’s Bay and Gisborne-East Cape in March 1988 and West Auckland’s infrastructure problems. Floods, power outages and a national emergency have displaced families and towns. Limit flood hazards, develop flood-resistant infrastructure, and create emergency response procedures to identify and repair flood damage to prevent future harm.

Floods affect the environment as well as homes and infrastructure. Floor collapses, foundation fractures, electrical line damage, and mould and mildew growth in homes can also destroy biodiversity in rivers and wetlands.

After the storm, old streams regained themselves, showing Auckland’s pre-colonial morphology; Urbanisation continues to produce floods. New Zealand must prioritise flood-resistant infrastructure and emergency response measures to reduce flood risk and safeguard communities. New Zealand’s flood insurance payouts and civil defence expenses demonstrate the necessity of flood prevention.

In conclusion, the Māori legend of the enormous deluge and New Zealand’s history of floods demonstrate the need for better building design and waterproofing. As we seek to improve flood prevention and management, we must recall the lessons of the past and the stories of our predecessors, like Tāwhaki, who protected their communities from floods.

Steps to take after a flood to assess and repair damage to your home, including working with your insurance company and engaging a professional building consultant – Explanation of New Zealand’s building codes and regulations, including requirements for building in flood-prone areas

Preparing For Future Floods in New Zealand

Floods in 2023 devastated New Zealand, causing landslides, infrastructure damage, power shortages, and a state of emergency. The New Zealand government has created programmes and services to help homeowners prepare for and respond to floods.

The New Zealand Ministry for the Environment produced guidance for local governments on planning for future flooding, including flood risk management. Identifying flood-prone locations, analysing flood risk, and designing flood mitigation techniques, including erecting flood barriers and elevating homes.

Private companies like I-Dry Restorations help homeowners recover from flood damage in addition to government initiatives. Emergency water extraction, drying, and dehumidifying, as well as property restoration, are their services.

Homeowners must also prepare for floods. The New Zealand Ministry of Civil Defence and Disaster Management provides materials and instructions for establishing a family emergency plan, including safe evacuation routes, an emergency evacuation kit containing water, food, and first aid supplies, and learning how to switch off electricity, gas, and water.

Floods destroy homes, infrastructure, and natural resources. Government programmes, corporate services, and personal planning can reduce flood risk and damage.

In summary, New Zealand flood risk management includes government-led initiatives to assess and manage flood risk, private flood restoration firms, and household tools to prepare for and respond to floods.

Working together and being proactive can help safeguard our communities from flooding. Flood mitigation strategies are essential to consider in areas prone to flooding. Several options are available, including creating flood barriers and elevating your home. 

Creating Flood Barriers

Flood barriers safeguard properties near streams, rivers, and other waterways. Flood barriers have numerous applications. Let’s explore the various flood barriers, extra precautions homeowners may take, and flood engineering services that can be used to control flood risk better.

Inflatable Water-Filled Flood Tubes

Inflatable water-filled flood tubes are portable, lightweight, and reusable flood protection solutions. The tubes can be quickly deployed to form a barrier against incoming floodwaters, protecting homes and businesses. 

Garrison Flood Defense offers a range of sizes and configurations to suit different flood protection needs, and the tubes can be filled with water using a standard garden hose. 

Key features of this flood barrier include:

  • Made of high-quality PVC material resistant to punctures, tears, and UV rays.
  • Suitable for various flood-prone areas, including coastlines, riverbanks, and urban regions.
  • Portable and lightweight, making it easy to transport and store.
  • Reusable and can be quickly filled and emptied.

Weta Water Barrier

The Weta Water Barrier is a patented, modular, and reusable flood barrier system that can be installed easily in minutes. The system is water-activated, and the water pressure activates the interlocking mechanism, creating a solid barrier.

It is also suitable for various applications, including roofing, cladding, and window installations, to provide a durable and reliable water barrier. 

Key features of this flood barrier include:

  • Self-adhesive butyl waterproofing tape creates a seal to prevent water from entering a building.
  • It is resistant to UV radiation and temperature fluctuations, making it suitable for hot and cold climates.
  • Straightforward to install and requires no special tools or equipment.
  • Comes in a range of sizes to accommodate different building needs.

Additional Measures to Prevent Flood Damage

In addition to using flood barriers, homeowners can take additional measures to prevent flood damage, such as:

  • Elevating their homes to make them less prone to flooding.
  • Installing check valves on pipes prevents a flooded sewage system from backing into the house.
  • Ensure all outlets, switches, sockets, and circuit breakers are at least one foot above flood level.

Flood Engineering Services

Flood engineering services can help manage flood risk and design effective mitigation measures. Thomas Consultants provides various services related to flood engineering, including flood risk assessments, flood modelling, and flood mitigation design. 

Their engineers have experience working on projects related to rivers, estuaries, and stormwater drainage systems. They use various software and modelling tools to assess and manage flood risk. Key features of their flood engineering services include:

  • Customised flood engineering services to meet the needs of local governments, property developers, and homeowners.
  • Use software and modelling tools such as GIS and hydraulic modelling software to assess and manage flood risk.
  • Experience working on a range of projects related to flood engineering.
  • Ability to design effective flood mitigation measures.

Flood barriers are critical structures that can be installed around a property to prevent floodwater from entering the area. Inflatable water-filled flood tubes and Weta Water Barriers are examples of flood barriers available in the market. 

In addition to using flood barriers, homeowners can take additional measures to prevent flood damage. Flood engineering services can also help manage flood risk and design effective mitigation measures.

Flood Barriers: Types and Effectiveness

Various options for flood barriers are available in the market, each with unique features and applications. These options include sandbags, inflatable barriers, and permanent ones like concrete walls.

However, the effectiveness of flood barriers depends on various factors, such as the type of barrier used, the flood conditions, and how well the wall is installed. For instance, sandbags are inexpensive and readily available, but their effectiveness could be improved as they are susceptible to erosion and displacement.

 Inflatable barriers, on the other hand, are portable, lightweight, and reusable, making them a popular option. However, their effectiveness depends on the materials’ quality, the barrier’s size and configuration, and how well they are installed.

Permanent barriers such as concrete walls are the most effective at preventing flood damage, but they are also the most expensive and require significant planning and construction. Thus, choosing the appropriate flood barrier and ensuring proper installation is crucial to prevent flood damage.

Above the Waterline: Elevating Your Home for Floods

Elevating a home by lifting the foundation involves raising the entire structure above its existing foundation to mitigate the risk of flooding or to address foundation problems. The steps involved in lifting a home vary depending on the type of foundation and the desired outcome.

Types of Foundations:

Houses in New Zealand are typically constructed on one of two types of foundation: concrete slab on the ground or a system of timber piles and bearers.

Pros and Cons:

Lifting a home can replace or strengthen the foundation and add more living space by constructing a basement or second story. Additionally, raising a home can reduce insurance premiums by 30% to 60% and increase resale value by 15% to 25%. On the downside, lifting a home is expensive, and the cost-benefit analysis should be considered before undertaking this project.

Foundation Problems:

Foundations can shift and settle over time due to poor soil strength, expansive clay, poor drainage, or poor grading before the foundation is poured. These issues can improve and compromise the home’s structural integrity. The cost of foundation repairs ranges from several hundred to thousands, depending on the extent of the damage.

Methods of Lifting:

Helical piers can be installed around the home’s exterior to repair foundation stability. Alternatively, if the foundation has shifted and settled to the point of creating structural problems, lifting the house and placing it on a new foundation or adding an elevated level may be necessary.

The most common methods for elevating a home are either raising the house and laying a new foundation or adding an elevated level.

Elevation Process:

Design specialists should evaluate the home before lifting it to consider hazards such as severe winds, earthquakes, and erosion.

Different homes require specific elevation methods, including frame, masonry veneer, and slab-on-grade homes. Popular methods include elevating foundation walls and expanding house walls.

Considering access and the home’s size, design, and form is crucial before selecting an elevation method.

Companies – NZ

Companies such as Mainmark and House Lifters Limited are available to provide services for house lifting, house repositioning, and foundation repairs.

In essence, elevating a property reduces flood danger, but it’s costly, so homeowners should weigh the pros and risks before doing it. For flood-prone homeowners, raising a property may minimise flood damage. 

Before elevating, homeowners should contact professional experts and examine local rules. Water-resistant materials, flood vents, drainage systems, and flood-resistant vegetation should also be considered. Before starting, seek professionals and follow local construction codes.

Flood Mitigation Strategies

Various materials and products, including roofing, flooring, and foundation, can be used for water protection and waterproofing. 

Additional strategies such as flood vents, waterproof building materials, and stormwater redirection can be used to mitigate the impact of floods. For instance, French drains, rain gardens, and wetlands can also help to minimise the damage caused by floods. 

Some examples of water protection products include:

These are just a snippet of the many materials and products available for water protection and waterproofing. The specific products and materials used will depend on the location, type of housing, and other factors.

Effective Waterproofing: Homeowners in New Zealand

Water damage can be a significant problem for homeowners, but effective waterproofing can help prevent it. Here are some tips and techniques for effective waterproofing in New Zealand:

Roof Waterproofing

  • Apply waterproof coatings, membranes, or sealants to roof joints and seams to prevent water from penetrating your roof.
  • Protect your assets with a waterproof and rustproof floor safe or a sliding door in front of your safe.
  • Apply anti-moss spray on roof tiles or cover them with potted plants to avoid heat accumulation and protect your roof from moss and other impurities.

Floor Waterproofing

  • Use low-tack tape to tie the floor protector to the ends and sides closest to the wall while moving heavy furniture.
  • Consult a professional to waterproof your flooring by smoothing and cleaning the substrate, applying the waterproofing membrane, and checking for leaks.
  • Shower floor and wall finishes must be impermeable, and tiles must absorb no more than 6% water.

Foundation Waterproofing

  • Excavate the ground around the perimeter of the foundations and seal all cracks in the concrete.
  • Apply a waterproofing membrane to the outside of the foundation and backfill the trench dug around the foundations.
  • Poly Wall® Waterproofing Barrier Systems are the best approach to waterproofing new foundation walls, significantly minimising moisture-related problems in your home.

Interior Waterproofing

  • Seal any potential water and moisture entryways in your property, including doors, windows, floor, and wall cracks.
  • Hydraulic cement is an excellent option for sealing cracks or holes in the concrete walls and the foundation.
  • A coat of waterproof masonry cement on the walls is a good idea.

Waterproofing Materials

Polyurethane, cementitious coating, EPDM rubber, rubberised asphalt, thermoplastic, bituminous membrane, and PVC waterproofing membrane are all effective materials. Choose the right one for your surface and consult an expert if necessary.

Ultimately, effective waterproofing helps prevent water damage and protect your belongings. When picking a waterproofing solution for your surface, contact an expert and follow the proper application procedures.

Interior waterproofing is often more cost-friendly than exterior waterproofing, but a professional can help you decide which option is suitable.

Flood Mitigation and Resources – New Zealand

Flooding can have a severe impact on communities in New Zealand. Here are some tips and resources to help mitigate flood damage and aid in recovery:

Solid Tips and Tricks:

  • Keep sandbags or other barriers on hand to block floodwaters from entering homes or businesses.
  • Keep essential documents in a waterproof container or safe.
  • Stay informed about weather patterns and flood alerts in your area.

Working with Local Authority and Correcting Them When They Get it Wrong:

  • Contact your local council for flood mitigation plans and resources.
  • Report any damages or issues with infrastructure, such as stopbanks or culverts, to the council.
  • If you believe the council needs to respond appropriately to a flooding event, bring it to their attention and consider contacting the ombudsman.

Addressing Issues with Silt and Forestry Debris:

  • Silt and forestry debris can clog up drainage systems and exacerbate flood damage.
  • Contact your local council for resources on adequately disposing of silt and debris.
  • Consider using vegetative measures, such as terraces or vegetation cover, to absorb water and prevent further damage.


  • Consult with your insurance company to understand coverage options for flood damage.
  • Consider building structures and waterproofing to protect against future flooding.
  • Contact the New Zealand Claims Resolution Service for expert support with insurance claims.

Helpful Hints for People Affected on How to Rebuild and Who Best to Contact:

  • Contact your insurance company and local council for guidance and resources on rebuilding after flood damage.
  • Consider consulting with professionals, such as builders or architects, to ensure proper waterproofing and flood mitigation strategies.
  • Look for aid from Habitat for Humanity New Zealand or the Emergency Relief Fund.

Local Law Office, Library, Finding People within the Community:

  • Check with local law offices or libraries for flood mitigation and recovery resources.
  • Connect with community members through local organisations or social media to share information and resources.
  • Contact your local community council for information on community outreach programs and aid initiatives.

In Auckland:

  • The government provides support and funding initiatives for disaster recovery and economic development, including the Freshwater Improvement Fund, the Primary Growth Partnership, and the Provincial Growth Fund.
  • The Ministry for the Environment offers guidance on flood risk management and resources for planning and response.
  • Effective flood risk management initiatives include the Community-Based Flood Mitigation and Management Program, Hill Country Erosion Programme, and solutions from companies like Binnies.
  • Sign up for flood warning alerts and prioritise catchments for freshwater farm plans to prevent future disasters.

In Northland:

  • Implement effective flood mitigation strategies such as structural, non-structural, and vegetative measures.
  • Consult with professionals and consider the specific circumstances of your property before choosing a flood mitigation strategy.

In flood-prone New Zealand, it is essential to establish a flood emergency plan for your family. Water damage prevention best practices include waterproofing, regular maintenance, and flood mitigation. Here are some practical tips to follow:


Waterproofing prevents water damage, so roofs, flooring, and foundations should be waterproofed. Installing waterproofing and sump pumps provides extra protection.


Asphalt shingles with waterproof underlayment: This involves installing waterproof underlayments, such as ice and water shield, before laying down asphalt shingles to prevent water from penetrating the roof

Metal roofs with sealant: Metal roofs can be sealed with various products, such as silicone, to prevent water from seeping through seams or gaps.

Roof coatings: A roof coating can be applied to a flat or low-sloped roof to create a waterproof barrier. Examples of roof coatings include acrylic, silicone, and polyurethane.

Sump plugs: Flat roofs often utilise sump plugs to avoid ponding. They create a hole on the roof surface to drain water to the drainage system below, improving drainage and reducing roof damage. Sump plugs prevent flat roof ponding and extend roof life.

TPO roofing membranes: These single-ply white roofing materials reflect heat and can last up to 25 years if properly installed. However, the white membrane may become dusty and affect the roof’s appearance over time.

Single-ply white PVC roofing membranes: These perform similarly to TPO but are more flexible and have been used longer. They also reflect heat, making them ideal for keeping a living area’s roof cool. However, they may fade over time.

EPDM roofing: This synthetic rubber black membrane absorbs heat instead of reflecting it, making it suitable for commercial and medical buildings. It can last up to 25-30 years if installed correctly, but it’s not ideal for bedrooms or living areas.

If you seek expert advice on waterproofing in West Auckland, look no further than Superior Waterproofing. As industry professionals, their trustworthy Waterproofing Technicians are committed to delivering top-notch solutions tailored to your needs. Choose Superior Waterproofing for reliable, high-quality services and experience the difference.


Concrete sealer: A concrete sealer can be applied to a basement floor to prevent moisture from seeping through the porous concrete.

Epoxy flooring: This excellent waterproof coating can be applied to various flooring materials, including concrete, to create a durable and long-lasting waterproof barrier.

  • Epoxy coatings – come in different forms, including water-based and solvent-based, and they are typically applied in multiple layers using a roller or a sprayer. Some popular epoxy flooring products include Rust-Oleum EpoxyShield, ArmorPoxy, and Epoxy-Coat.
  • Rubber or PVC flooring: is a great waterproof option for areas where moisture is a concern, such as basements and laundry rooms. These materials are naturally resistant to water and can withstand spills, leaks, and flooding.
  • Rubber and PVC flooring – comes in various shapes and sizes, including tiles, rolls, and mats. Some popular rubber and PVC flooring options include Tuff-N-Lastic, Diamond Nitro Rolls, and Interlocking Rubber Floor Tiles.

Installing these flooring types properly ensures they are entirely sealed and provide optimal waterproofing protection.

Installing a sump pump: A sump pump can be installed in the basement to remove any excess water seeping through the flooring.


Waterproofing a house’s foundation prevents water damage and preserves its structure. DIY and professional foundation waterproofing options exist.

  • Applying a waterproofing membrane to the foundation’s outside is one of the more effective methods. This requires digging the earth surrounding the foundation and waterproofing its exterior. The waterproofing membrane separates the foundation from the earth, preventing water from entering the structure via the concrete.
  • A perimeter drainage system may also waterproof a foundation. This entails digging the earth around the foundation and constructing a French drain to divert water from the structure. Sump pumps may drain surplus water from the drainage system.
  • A waterproofing sealer or paint may waterproof a foundation’s interior. These treatments may need regular reapplication and may not give long-term protection.
  • Professional waterproofing may require excavation, drainage, and membrane application. It’s complicated and expensive, but it protects the structure from water damage and lasts.

Regularly examine and maintain the roof, gutters, downspouts, foundation, and waterproofing. Frequent inspections may discover possible flaws before they become severe problems and enable rapid fixes.

Leaks blocked gutters and drains, and improper water connections should be fixed immediately to avoid structural damage. These standard construction methods may help homeowners waterproof their foundations.

Flood Mitigation

  • Elevate or build flood barriers to prevent flood damage.
  • Create a family flood strategy and stockpile emergency supplies for extra safety.
  • New Zealand’s history of disastrous floods has shown the significance of better building design and waterproofing
  • We can safeguard our communities by learning from the past and prioritising flood-resistant infrastructure.
  • Flood mitigation options include installing inflatable water-filled flood tubes or modular, reusable flood barriers. (To avoid flooding and foundation difficulties, lift your home above the waterline.)

Foundation Maintenance and Repair

  • Maintaining and fixing your foundation prevents water damage and preserves its structural integrity. 
  • Foundation cracks should be checked routinely. Soil movement, water pressure, and temperature variations may create leaks and structural instability.
  • Get a professional to evaluate and repair your foundation periodically. 
  • This may include sealing water-entry fissures. Your home’s drainage and water concerns must also be addressed.
  • Maintaining house drainage prevents soil erosion and foundation damage. 
  • Gutter and downspout installation and sloping the land around the foundation to slope away from the house may enhance drainage.

Basement Waterproofing

  • Basement waterproofing has interior and outdoor solutions. Internal basement waterproofing is less offensive than exterior waterproofing. 
  • DIY waterproofing inside basement walls costs $6 to $7 per square foot, whereas professional waterproofing costs $10.25.
  • External basement waterproofing alternatives include a minimum 100 mm diameter perforated subsoil drainage pipe placed at the base of the wall on free-draining metal at a level above the foundation, ensuring the invert drain level is at least 200 mm below the completed floor level. 
  • Water-permeable cloth prevents pipe blockage. Outside waterproofing costs more than inside.
  • Sump pumps drain basement water and is crucial to waterproofing. 

(The kind of sump pump, basement size, and installation difficulty determine the cost. Interior basement waterproofing, including a sump pump, costs $200–$3,000.)

Insurance Coverage

  • Reviewing and upgrading your insurance coverage is crucial to protecting yourself and your belongings.
  • A yearly evaluation ensures continuing coverage and maximises discounts and savings.
  • Regularly reviewing term life insurance and business insurance ensures it suits your needs.
  • Update your homeowner’s insurance for firm longevity.
  • Working with an insurance broker, obtaining the lowest rate, considering additional coverage for high-risk vocations, and checking your policy regularly may protect your career and possessions.

Waterproofing protects your property from leaks, floods, and severe rain, retains its structure, and lowers insurance claims. Proactive risk management may decrease insurance rates.

A well-maintained, waterproofed house attracts purchasers and ensures sufficient insurance coverage. Insurers are more likely to accept and handle claims promptly if a home is waterproofed.

Finally, waterproofing prevents mould and mildew growth, keeping inhabitants healthy and reducing health-related liability claims. Waterproofing protects your property and your insurance.

The Science of Waterproofing

Check out this fascinating video that delves into the science of waterproofing! From ancient techniques to modern solutions, you’ll learn how proper waterproofing ensures the longevity of our infrastructures.

The Engineering Hub. (2022, December 31). Waterproofing 101: The Science of Keeping Water Out of Buildings [Video]. YouTube.

So, let’s explore the secrets behind how structures stay dry and evolve with society’s demands.


New Zealand has a history of floods, and it’s crucial for homeowners to protect their homes from water damage, especially if they’re in flood-prone areas

To prevent water damage, waterproofing, maintenance, and flood mitigation are essential, as well as elevating homes, building flood barriers, and making a family flood plan. 

Effective flood protection measures like inflatable flood tubes and flood barriers like the Weta Water Barrier exist. Regular maintenance checks and proper drainage can also help prevent water damage. 

By taking preventive measures and utilising available resources, we can minimise the impact of floods and keep our communities safe.

Sources of Infomation

Flood Restoration In Auckland, NZ | iDry Restorations. (2022, August 13). iDry Restorations.

I. (2023, February 28). Climate of Fear: Outdoor Phone Store.


Metis Consultants – Land Development – Civil & Environmental Engineering. (2021, May 25). Metis Consultants.

Farm Bureau Financial Services. (2021, June 7). Life Insurance Needs at Different Stages in Life.

Ltd, M. (n.d.). Builderscrack | Find NZ Tradespeople. Builderscrack.

Top Waterproofing Systems Tauranga | Versatile Waterproofing Solutions. (2021, July 20). Versatile Waterproofing Solutions.

Quimby, S. (2019, December 4). Get Downspout Drainage Away From Your Foundation » Frontier Tips Notebook. Frontier Tips Notebook.

(2006, November). Overview of Flood Management Legislation in New Zealand. Retrieved March 18, 2023, from

Ministry for the Environment. (2010). Preparing for future flooding. Ministry for the Environment -NIWA, ME 1012, 978-0-478-33280–3.

Special Solutions Trade Company. (n.d.). Special Solutions Trade Company.

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