Modern building systems like Dincel, Rediwall, Rise Products and Clearform have made construction faster and more efficient – but they also bring new challenges when it comes to keeping water out.
Without the right waterproofing strategy, issues like efflorescence, persistent leaks and long-term structural damage can quickly emerge, leading to costly repairs and safety concerns.
This is where negative cementitious waterproofing becomes a reliable solution.
Unlike traditional methods that only deal with water from the outside, this waterproofing system is designed to resist negative hydrostatic pressure: the force of water pressing through walls or slabs from the outside in. It’s one of the most common problems in basements, retaining walls and below-ground structures.
To show how this works in practice, we recently connected with the team at FANDR Constructions[AM1] [JA2] , who put Drizoro products to the test on a complex basement project.
Read on to discover how negative waterproofing works, the waterproofing products that make it possible and the lessons learned from this real-world application.
What is negative cementitious waterproofing?
When most people think of waterproofing, they picture applying a membrane to the outside of a wall or slab to block water at the source. This is called positive waterproofing.
But in many cases, like basements, lift pits or retaining walls, it’s not possible to access the outside face once the structure is built.
That’s where negative waterproofing becomes essential.
Negative cementitious waterproofing is applied to the inside face of a structure to resist negative hydrostatic pressure – the force of water pushing through concrete or masonry from the outside in. Waterproofing products like Drizoro®are engineered to meet this exact challenge. They penetrate the substrate, bond tightly even to a wet surface and remain flexible under pressure.
Because the positive surface side isn’t always accessible, negative waterproofing provides builders with a reliable solution.
The key is correct waterproofing application: Drizoro waterproofing membranes must be brushed onto a thoroughly wet surface, so it enters the pores of the substrate as rolling won’t deliver the same level of protection.
Key challenges in waterproofing modern systems
Negative cementitious waterproofing provides a reliable way to handle water pressure when you can’t access the outside face of a structure.
But to appreciate why it’s so effective, it helps to look at the challenges builders face with today’s construction systems.
Permanent formwork systems such as Dincel, Rediwall, Rise Products and Clearform have become increasingly popular in modern projects. They speed up construction and deliver strong structural results – but they also present unique waterproofing challenges. Some of the most common waterproofing issues include:
- Water ingress through joints and cracks: Even small gaps between panels can allow water to track through.
- Efflorescence: Mineral salts carried by water can leach out and stain surfaces, leaving a white crystalline residue.
- Persistent dampness: If not treated, moisture build-up can weaken finishes, damage interiors and lead to mould growth.
Beyond the surface issues, these systems require careful planning around drainage and substrate preparation. Without proper backfill, drainage cavities and attention to detail, any applied membrane will be under unnecessary stress.
This is why negative waterproofing is so important for structures built with permanent formwork.
Once the walls are in place, access to the positive side is limited or impossible – making a cementitious system like Drizoro® products the most reliable way to resist water pressure from the inside.
The solutions behind the FANDR basement project
When it came to waterproofing a basement renovation project with retaining walls and underpinned slabs, the team at FANDR Constructions turned to Scientific Waterproofing Products for proven solutions.
With water pressure pushing from the outside in, a negative cementitious system was the only way to ensure long-term protection.
Here’s the toolkit that made it possible:
- Drizoro MAXSEAL® Flex
- A two-component, flexible waterproof coating designed to be applied to wet surfaces. Unlike traditional membranes, it doesn’t just sit on top of the wall, it enters the substrate, creating a barrier that resists both positive and negative hydrostatic pressure. This makes it especially effective for retaining walls and below-ground slabs where outside access is limited.
- Drizoro MAXMESH
- An open-weave mesh that reinforces critical areas. At cold joints, junctions or transitions between materials, MAXMESH is embedded into the first coat of MAXSEAL® Flex to provide extra tensile strength, reducing the risk of movement cracks over time.
- Drizoro MAXJOINT® Elastic
- A flexible joint sealant for both positive and negative hydrostatic pressure, applied to a wet surface, formulated for active control joints. It stretches and moves with the substrate while maintaining a watertight seal, preventing leaks where structural movement is expected.
- Drizoro MAXREST®
- A high-performance repair mortar used to patch cracks or voids larger than 3mm before waterproofing begins. By smoothing and sealing damaged areas, it ensures the membrane has a sound, continuous surface to bond with.
- Drizoro MAXGRIP®
- A rapid-setting, waterproof anchoring mortar. It was used to secure fixings and penetrations in the concrete without creating weak points in the system, keeping the entire structure watertight.
The waterproofing process itself was straightforward but critical:
- Substrate preparation: Repairing cracks or voids over 3mm with MAXREST where needed, and ensuring surfaces are sound, clean and damp (as MAXSEAL® Flex requires a wet substrate for best adhesion).
- Membrane application: Applying MAXSEAL® Flex in coats, with MAXMESH embedded in stress points for extra durability.
- Joint treatment: Using MAXJOINT® Elastic to ensure all control joints were fully sealed and flexible.
- Fixings and service points. Applying MAXGRIP® to secure elements into the concrete without compromising waterproofing integrity.
Together, these waterproofing products formed a completely negative waterproofing system that gave the basement structure long-term resistance against water pressure.
How FANDR and SWP delivered a lasting waterproofing result
For the basement renovation, FANDR Constructions took the lead on-site, applying SWP’s Drizoro® system to tackle the challenge of negative hydrostatic pressure.
The FANDR team handled the substrate preparation, membrane application and joint sealing, while the SWP technical specialists provided guidance to ensure every step was carried out to specification.
The result is a robust waterproofing system that protects the retaining walls and underpinned slabs against leaks, efflorescence and long-term water damage.
By pairing FANDR’s construction expertise with SWP waterproofing solutions, the project achieved a finish built to stand the test of time.
Solve water challenges the right way with SWP’s expertise and products
At Scientific Waterproofing Products, our team is here to provide you with the most effective waterproofing product for your unique project.
For any questions about your next waterproofing job, or which product is best for your project, contact us today.
You can also check out a list of local Drizoro resellers and applicators here.
SWP is committed to providing the right waterproofing solution for any water-related problem or application.