Remedial Waterproofing Solutions & Services

Waterproofing is crucial for any construction project, whether residential or commercial. Proper remedial waterproofing in Sydney prevents water penetration or ingression, which can cause structural damage, mould growth and other issues. Without adequate waterproofing, a building can deteriorate quickly and become uninhabitable.

Our Clients

MJ Engineering Projects - Sydney - Remedial Waterproofing

What To Expect From Our Waterproofing Consultants

At MJ Engineering Projects, we specialise in remedial waterproofing services for buildings to repair existing failed waterproofing systems. We understand the importance of proper waterproofing in construction projects to prevent water damage, structural deterioration and potential health hazards such as mould growth.

Our experienced Australian waterproofing consultants have the expertise to identify the underlying cause of waterproofing issues. We provide a comprehensive solution that includes diagnosing the issue and providing specifications to prevent future water penetration.

Remedial Waterproofing Repair Process

With over 18 years of industry expertise, our waterproofing consultants at MJ Engineering Projects have built a reputation for delivering reliable and compliant waterproofing solutions. We work to the highest standards, ensuring projects align with the NCC and relevant Australian Standards.

Our process combines innovative diagnostic techniques with proven repair methodologies to achieve lasting outcomes. By tailoring solutions to each building’s unique conditions, we provide clients with certainty, quality and peace of mind.

Remedial Waterproofing

Options For Waterproofing Repair

When it comes to waterproofing repairs, there are several options available. If the damage to the waterproofing system is not too severe, it may be possible to repair the existing system. This is often the most cost-effective approach, as it involves our waterproofing consultants fixing the current system rather than replacing it entirely. Repairs include patching cracks or holes, sealing gaps and re-applying waterproofing products.

A full system replacement may be necessary if the existing waterproofing system is beyond repair or if a partial replacement would not be effective. While this can be costly, ensuring the building is adequately protected from water intrusion is often necessary.

Industry Affiliations

Balcony/Terrace Waterproofing

Balcony-Terrace Waterproofing

Balconies and terraces commonly fail at door thresholds, ponding areas, balustrade fixings and movement joints. We investigate falls, drainage and substrate condition, then design a system that addresses the root cause, not just the symptoms. Typical solutions include re-grading screeds, installing flashings, banding joints, and applying compatible membranes with protection boards and slip-resistant finishes.

Our details follow the NCC weatherproofing requirements and relevant Australian Standards such as AS 4654.1/2 for external above-ground membranes. We specify drainage outlets and overflows, conduct flood tests, and implement site QA to verify coverage and thickness. The result is a durable, maintainable balcony or terrace that sheds water correctly and prevents leaks to apartments below.

Roof Waterproofing

A watertight roof protects everything beneath it. Indicators such as ceiling stains, rusted gutters or leaks around penetrations warrant a professional review. We evaluate the existing roof system, falls and outlets, then recommend a clear solution. This may involve repairing flashings, overlaying a new roof membrane, improving drainage or detailing penetrations to accommodate plant and solar equipment.

Our emphasis is on long-term performance and straightforward maintenance. We coordinate safely around live services, provide regular progress updates and deliver concise care instructions at completion. Roof waterproofing undertaken in this manner reduces call-outs, extends service life and improves building resilience during heavy rainfall events. MJ Engineering Projects provides a watertight outcome supported by transparent documentation and practical maintenance guidance.

Roof Waterproofing

Planterbox Waterproofing

Planterbox Waterproofing

Leaking planter boxes can stain façades, deteriorate finishes and introduce moisture to interiors. Successful remediation considers the entire assembly rather than the membrane alone. We review structural falls, outlet capacity and irrigation settings, then develop a build-up that allows water to move freely out of the planter. Typical solutions combine a compatible membrane, protection layer, drainage cell, geotextile, root control and a free-draining soil blend, with an overflow sized for peak rainfall.

Prior to reinstatement, outlets are verified and flood testing is completed to confirm performance. Clear guidance is provided for irrigation and seasonal maintenance. Whether located on balconies, podiums or rooftops, our planter box waterproofing supports healthy planting while protecting the building fabric. The result is a clean façade and dry internal spaces.

Bathroom and Internal Wet Areas Waterproofing

Wet area failures commonly arise from inadequate falls, poor junction detailing and incompatible materials. Warning signs include swollen skirtings, loose tiles and odours. Our approach establishes correct falls to the waste, applies a tested membrane system and seals all corners and transitions prior to tiling. Movement joints and set-outs are coordinated so the finish performs as intended.

Execution is carefully staged to suit occupants or programme requirements. Dust and noise are controlled, surfaces are protected and the area is left tidy at the end of each shift. Final checks confirm watertightness before handover. For bathrooms, ensuites and laundries, this method provides a durable and hygienic finish that remains easy to clean and resistant to leakage over the long term.

MJ Engineering Projects Sydney Remedial Engineers Bathroom and Internal Areas Waterproofing

Underground Areas Waterproofing

Underground Areas Waterproofing

Basements, car parks and lift pits are exposed to persistent moisture and groundwater pressure. Typical symptoms include damp walls, peeling coatings and recurring puddles. We trace the water path to its source, then select a practical remediation method for the conditions present. Solutions may include internal treatments, joint sealing, targeted injection works and drainage improvements such as sump and pump upgrades.

Programming is planned to maintain access and safety wherever possible. Stakeholders receive regular updates, and the site is presented neatly throughout delivery. At completion we provide simple maintenance guidance for pumps, drains and joints to preserve performance. Our underground waterproofing restores dry, usable spaces and reduces the likelihood of ongoing moisture-related issues within the asset.

The MJ Engineering Projects Experience

Remedial Waterproofing

Over 18 Years Of Experience

With more than eighteen years of proven experience in remedial engineering, our firm has built a strong reputation for delivering reliable and long-lasting results. As registered design practitioners, we specialise in repairing building defects across a wide range of projects, from heritage façades that require delicate restoration to modern high-rise towers that demand technical precision.

Our structured project management approach, combined with thorough quality control processes, ensures every repair is handled with efficiency and care. We focus on minimising disruption, controlling costs and tailoring repair strategies to meet the unique requirements of each client.

This commitment to detail and excellence enables us to consistently provide durable, value-driven solutions that stand the test of time.

Leading industry expertise

Leading Industry Expertise

Our engineers bring extensive expertise in remedial engineering, supported by years of specialised experience and a detailed understanding of industry standards. We take pride in delivering tailored remediation strategies that address both visible and hidden defects across a wide range of building types.

By staying informed of changing regulations and compliance requirements, our team ensures every project achieves technical excellence and long-term durability. We also place a strong emphasis on sustainability, applying environmentally responsible practices and innovative methods wherever possible.

From diagnosing complex issues to implementing cost-effective repair programs, we are committed to providing clients with outcomes that are reliable, compliant and built for the future.

Over 1,000 Buildings

Over 1,000 Buildings

We have successfully completed inspections and remedial work on more than one thousand residential, commercial and industrial buildings across Sydney. This extensive experience allows us to identify and resolve issues with accuracy, from water ingress and façade deterioration to concrete spalling and structural concerns.

Each project benefits from a customised repair strategy designed to achieve durability, compliance and lasting performance. Our large and diverse portfolio equips us to anticipate challenges, optimise resources and streamline delivery to minimise site disruption.

With this proven track record, we are confident in managing projects of any scale or complexity, delivering solutions that are efficient, cost-effective and built to endure.

Reach Out To MJ Engineering Projects For Your Remedial Waterproofing Needs

Don’t let water damage undermine the safety and value of your property. Take proactive steps today by choosing MJ Engineering for comprehensive building waterproofing services by our industry-leading waterproofing consultants in Australia.

With over 18 years of industry-leading experience and a track record of inspecting and protecting over 1,000 buildings in Sydney, we offer unmatched expertise and reliable solutions tailored to your specific needs. If you have any questions, contact our team, who will be happy to assist.

Certifications

Use Cases

Little St, Lane Cove

Client: Owners Corporation

Remedial works at Little Street, a three-storey strata complex of eight apartments in Lane Cove, have repaired concrete spalling, renewed balcony finishes and introduced...

Milsons Point

Client: Owners Corporation

Remedial works at Milsons Point have stopped persistent water ingress, repaired concrete damage and delivered a modern balcony enclosure that satisfies the Design and...

Kensington

Client: Owners Corporation

Remedial works at Kensington tackled persistent balcony leaks, blocked scuppers and early concrete decay that were staining interiors and increasing insurance risk. MJ Engineering...

Other Related Services

Window & Door Repairs

Window & Door Repairs

MJ Engineering Projects conducts window and door rectification to ensure functionality, water tightness and compliance with BCA.

Tender Processing

Tender Processing

MJ Engineering Projects conducts a tender process with several specialised remedial contractors to ensure the best fit for the job.

Technical Specification

Technical Specification

MJ Engineering Projects provides an in-depth specification to ensure remedial rectification works are completed in a methodical manner.

Superintendent Duties

Superintendent Duties

MJ Engineering Projects acts on behalf of the client for all Remedial Building Services to ensure the contractor completes a smooth rectification process.

Maintenance Planning

Maintenance Planning

MJ Engineering Projects conducts an inspection of your assets and provides a maintenance regime plan to optimise cost savings.

Magnesite Repairs

Magnesite Repairs

MJ Engineering Projects conducts floor topping investigations and repairs to prevent and rectify corrosion to the internal concrete slab.

Inspection Reports

Inspection Reports

MJ Engineering Projects conduct inspection reports that highlight building defects and recommend rectification methods.

Facade Rejuvenation

Facade Rejuvenation

MJ Engineering Projects conducts facade rejuvenation to ensure optimal performance and appearance of the building.

Expert Witness Reports

Expert Witness Reports

MJ Engineering Projects specialises in delivering thorough and litigation-compliant expert witness reports for construction claims, tailored for building dispute resolution cases.

Diagnostic Investigations

Diagnostic Investigations

MJ Engineering Projects conducts diagnostic investigations prior to remedial works to search for any potential building deficiencies.

Design Practitioner

Design Practitioner

MJ Engineering Projects provides expert design practitioner services, specialising in regulated designs and technical specifications for Class 2, 3, and 9c buildings.

Concrete Spalling Repairs

Concrete Spalling Repairs

MJ Engineering Projects conducts concrete corrosion repair as part of its Remedial Building Services to return the structure to its sound and safe state.

Cladding & Fire Protection

Cladding & Fire Protection

MJ Engineering Projects conducts rectification of existing cladding that is both unsafe and non-compliant with the BCA.

Balustrade Replacement

Balustrade Replacement

MJ Engineering Projects conducts ballustrade rectification to ensure compliance to the BCA and safety to the public and building occupants.

Balcony Repairs

Balcony Repairs

MJ Engineering Projects specialises in expert balcony repairs, ensuring safety, compliance, and long-lasting solutions tailored to your property needs.

FAQs About Remedial Waterproofing Repair Services

Key Concerns and Frequently Asked Questions About Remedial Waterproofing Repair in Australia

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What Are The Common Reasons For Waterproofing Failure?

Waterproofing systems can fail for several reasons, including:

  1. Poor Installation: Inadequate installation is one of the most common reasons for waterproofing failure. If the waterproofing system is not installed correctly, it may not withstand water pressure or other environmental factors. Poor installation can include incorrectly applying waterproofing products, using inferior quality materials and not following the manufacturer’s installation instructions.
  2. Wear and Tear: Over time, even the most robust waterproofing systems can become damaged or worn out, leaving them vulnerable to leaks and other problems. Exposure to UV rays, changes in temperature and humidity and mechanical damage can all contribute to wear and tear. Chemical exposure, such as in cleaning products or nearby construction, can damage waterproofing systems.
  3. Structural Damage: Structural damage to a building can also lead to waterproofing failure. If the foundation of a building shifts or settles, it can cause cracks in the walls or floors, leading to water intrusion. Similarly, if the building settles unevenly, it can cause the waterproofing system to stretch or tear, leading to leaks.
  4. Environmental Factors: Extreme weather conditions, such as heavy rain or flooding, can also cause waterproofing systems to fail. When a building is exposed to prolonged periods of heavy rain or flooding, water can seep into the structure and compromise the waterproofing system.

The impact of waterproofing failure can be severe and may include the following:

  1. Structural Damage: Water intrusion can cause significant structural damage to a building, leading to costly repairs. Over time, water can weaken the structure of a building and lead to the rotting, rusting or warping of building materials. This can compromise the integrity of the building and make it unsafe to occupy.
  2. Health Hazards: Water intrusion can also lead to mould growth, which can be hazardous to human health. Mould can cause respiratory problems, allergic reactions and other health issues. Additionally, water damage can create an environment that promotes the growth of bacteria and other microorganisms, harming human health.
  3. Cosmetically Unappealing: In addition to structural and health hazards, water intrusion can cause cosmetic damage, such as peeling paint or wallpaper, which can be unsightly. This can negatively impact the value of the building and create a negative impression on visitors or customers.

The investigation may also involve reviewing construction documents and historical data. After the assessment, findings are compiled into a detailed report outlining the nature, extent and cause of the issues, along with recommendations for remedial works to restore the building’s integrity and safety.

Regular waterproofing inspections and maintenance can help prevent more significant problems from occurring down the line. By detecting and addressing minor issues early on, building owners can avoid more extensive and costly repairs later.

It is important to consider local codes of compliance when undertaking waterproofing repairs. In Australia, waterproofing repairs must comply with the Building Code of Australia (BCA). The BCA outlines the requirements for waterproofing in various buildings, including residential and commercial buildings. At MJ Engineering, we can assist with the tender process to find a suitable contractor who adheres to all relevant codes and regulations for waterproofing repairs.

Services may involve repointing mortar joints, replacing damaged materials, applying protective coatings and waterproofing. Additionally, upgrading insulation and improving thermal performance might be included. These services enhance the building’s aesthetic appeal and ensure it’s protected against weathering and environmental damage.

As consultation and repair project management experts, we assist a wide range of clients in need of remedial waterproofing in Sydney. Our services are available to:

  • Strata managers
  • Asset managers
  • Facility managers
  • Residential unit owners
  • Builders and developers

Whether you’re managing a large strata complex or need waterproofing solutions for a private residence, our team is here to help. Contact us to discuss your waterproofing needs and find the best solution for your property.

Insurance statistics show the highest number of waterproofing failures stem from issues with the balconies, terraces, rooftops in high-rise dwellings and commercial buildings. There are a number of issues that may be the cause, including;

  1. Use of cheap/inferior materials to save money.
  2. Railing posts and penetrations causing water ingress due to poor preparation and detailing.
  3. Failure to pick up building defects through the building surveyors’ inspection process.
  4. Inadequately waterproof detailing from balcony to wall interfaces
  5. Poor design criteria within many buildings, which lack appreciation of water control, leading to costly damage that can be difficult to properly remedy.

The simple fact is that waterproofing membranes are only as good as the surface to which they have been applied or installed. The single biggest cause of waterproofing failures stems from poor workmanship, making it more crucial than ever to entrust your waterproofing needs to reliable and proven builders. It’s important to remember the failure of a waterproofing membrane or device can occur at any stage of the life of a building – it may fail straight away or after 1, 5, 12 or 20 years.

Simply put, water ingress is when water from outside gets into a building. It can happen in many different ways and for many different reasons in a building or property.

To determine the responsibility of water damage, it is important to find out where the water damage or water leak started.

Common strata property is everything outside of the individual units or apartments. This includes the hallways, lobby, lifts, stairs, car parks, gardens, gyms, swimming pools and so on. It also includes the walls that connect the units and flats as well as any other space that isn’t on the building plan for a specific unit. If water damage to a strata property starts here, it usually could be claimed that the owner’s corporation is responsible for the water damage.

On the other hand, a unit or apartment is a private space in the house. According to NSW Fair Trading, “the basic rule is that everything inside the airspace of the unit, including all internal walls, fixtures, kitchen, bathroom and paint on the walls, is usually the lot and, therefore, the responsibility of the unit/apartment owner.” If the water damage comes from inside a unit or flat, the owner of the unit/apartment is usually responsible for fixing it.

In addition to our building waterproofing services, MJ Engineering offers a range of solutions to help maintain and restore buildings, ensuring long-term structural integrity:

  • Remedial diagnostic investigations – We conduct thorough assessments to identify potential building issues before they escalate, helping property owners address concerns early.
  • Remedial concrete spalling repairs – We repair deteriorating concrete caused by water damage, chemical exposure or environmental wear, preventing further structural weakening.