Residential
Below-Ground Waterproofing (Exterior)

We carefully excavate a trench alongside the affected wall down to the footing, exposing the full area requiring waterproofing. A high-performance SBS torch-on membrane is then applied to the exterior wall, creating a continuous waterproof barrier designed specifically for below-ground tanking.

A protection and drainage layer is installed over the membrane using a drainage board system, while a Novacoil drain is placed at the footing level and connected to a suitable discharge point, such as stormwater, a natural gravity outlet, or a sump pump system.

The excavation is then backfilled with free-draining scoria to relieve hydrostatic pressure, before the area is reinstated and left neat and tidy. The result is a complete waterproofing and drainage system that prevents water from reaching the wall in the first place.

We hand-dig almost all of our excavations, so tight access is rarely a problem. Unlike machinery, hand excavation allows us to work safely around underground services, cables, pipes, gardens, and existing landscaping with minimal disruption. A trench is typically excavated approximately 600mm wide alongside the affected wall and taken down to the footing, regardless of depth. This careful approach helps protect your property while giving us the access needed to install a complete waterproofing system.

We take every reasonable step to minimise disruption to your property. Excavated soil is neatly stockpiled, pathways are protected where required, and gardens are carefully worked around wherever possible. While some disturbance is unavoidable during excavation, all areas are reinstated on completion and left clean and tidy. We treat your property as if it were our own.

We take every reasonable step to minimise disruption to your property. Excavated soil is neatly stockpiled, pathways are protected where required, and gardens are carefully worked around wherever possible. While some disturbance is unavoidable during excavation, all areas are reinstated on completion and left clean and tidy. We treat your property as if it were our own.

Most residential waterproofing projects take between 3 and 10 working days, depending on the length of wall, excavation depth, access, weather conditions, and drainage requirements. In almost all cases, you can remain in your home throughout the works, as the waterproofing is completed from the outside of the building.

Every project is different, but most residential below-ground waterproofing projects range between $10,000 and $45,000. A typical single-wall excavation and tanking project is often around $10,000–$20,000, while larger projects involving two or three walls around a property can range up to $45,000 or more, depending on depth and access requirements.

These price ranges are generally based on excavations up to approximately 1.5 metres deep. Where excavations extend beyond this depth, additional safety measures such as shoring, benching, or engineered support systems may be required, which can increase the overall cost.

The main factors affecting price are the length and depth of excavation, ease of access, drainage requirements, existing landscaping, ground conditions, and the condition of the wall. Following a site inspection, we provide a detailed fixed-price quotation so you know exactly what is included before work begins.

Our below-ground waterproofing system is designed as a long-term solution. The tanking membrane system we use has an expected durability of up to 50 years when correctly installed and protected, and we provide a 10-year workmanship warranty on our installation.

Because we waterproof the wall from the exterior and install proper drainage in accordance with proven moisture-management principles, failures are extremely rare. Unlike internal coatings that simply hold water back after it has entered the wall, exterior tanking prevents moisture from reaching the structure in the first place. If an issue does arise during the warranty period, we will inspect the area and rectify any workmanship-related defects covered under our warranty.