Foundation and Below-Grade Waterproofing
Protecting the parts of the structure in contact with the ground against groundwater and moisture. Waterproofing systems that secure the building’s service life from the very start, from foundations to retaining walls.
The best waterproofing is the one born with the structure.
Water below grade is the structure’s quietest enemy. Moisture working its way in through foundation and basement-wall surfaces in contact with the soil starts a damage process that grows over the years, from rebar corrosion to basement spaces becoming unusable. And reaching these zones later is harder and more costly than anywhere else in the building.
That is why the soundest approach is to plan the waterproofing together with the structure. In new buildings we plan the system from the design stage onwards; in existing buildings we assess the source of the water and the access conditions on site, and define the most suitable approach from the outside or the inside.
- Integrated design in new builds: The waterproofing is planned as a natural part of the construction process.
- Diagnosis first in existing buildings: No system is selected before the water source and access conditions are established.
- Continuity of details: Uninterrupted protection at pipe penetrations, cold joints and transitions.
- Documented application: Every layer that will be covered and never seen again is recorded.
On every surface where the structure meets the ground.
Below-grade waterproofing requires a holistic approach covering all parts of the structure in contact with water.
Foundations and rafts
The surfaces the structure sits on, where later access is impossible.
Basement retaining walls
Basement wall surfaces in vertical contact with the soil.
Basement spaces
Below-grade spaces intended for dry, healthy use.
Elevator and utility pits
The lowest points of the structure, the most exposed to water.
Retaining structures
Walls carrying earth loads under constant moisture exposure.
Transition details
Pipe penetrations, cold joints and element connections.
Views from the field.
Sample images from applications in different buildings and conditions.
What will never be seen must be built with the greatest care.
Once applied, below-grade waterproofing is covered with soil and never seen again. That is why every layer must fully perform its duty, and the application must be verified before it is closed up.
- Backfill / soilThe medium covering the waterproofing, in constant contact with the system.
- Protection layerThe layer protecting the waterproofing from mechanical damage during and after backfilling.
- Waterproofing layerKeeping the water away from the structure: the layer carrying the system’s real duty.
- Surface preparationThe stage where the surface is prepared so the waterproofing can be applied without interruption.
- Structural elementThe concrete structure the system protects, its condition assessed beforehand.
The right approach for the building’s condition.
Below-grade waterproofing is not a single method but a family of approaches adapted to the building’s age and access conditions.
External application in new builds
Waterproofing planned at the right time, as part of the construction process.
External renewal on existing buildings
Renewing the waterproofing from the outside where perimeter excavation is possible.
Internal application
A solution from the inside where external access is not possible.
Detail and transition solutions
Localized continuity at pipe penetrations, joints and connections.
What is expected of below-grade waterproofing.
Protects the building’s service life
Prevents water and moisture from working into the structure from the start.
Protects the reinforcement
Reduces moisture-driven corrosion risk at its source.
Usable basements
Keeps below-grade spaces dry and healthy.
Verified application
Layers inspected and recorded before being closed up.
Supports indoor comfort
Prevents moisture-driven odors and deterioration.
Continuity in the details
Provides uninterrupted protection at transition points.
As the water’s effect grows, the system’s scope expands.
The classification below is indicative only. The final system is determined by assessing ground conditions, the water situation and the building’s intended use on site.
Below-grade waterproofing, or another system?
If your situation is close to one of the following, let’s evaluate a more suitable system together.
Technical documents for members
Technical data sheets, safety data sheets and application specifications are available in the membership area open to corporate clients, architects and engineers. Access is free with membership.
Other waterproofing systems
Let’s protect your structure from water from the very start.
Are you planning a new project, or seeing signs of moisture in your existing building? Let us assess the site and propose the right approach for you.