Weatherproofing in 3DCP Homes
Solutions for New Technology
NCC 2022 Volume 2
Area of NCC Requirements:
- H2P1 – Rainwater Management
- H2P2 – Weatherproofing
- H2P3 – Rising Damp
The Challenge
3D concrete printing (3DCP) is revolutionising the way we think about residential construction. The technology offers precision, reduced waste, and the freedom to create designs that are difficult (or impossible) with conventional methods.
But concrete alone isn’t a silver bullet against moisture.
While the printed layers of concrete have excellent compressive strength, the surface can still be porous, and without proper detailing, moisture can travel through the wall profile or accumulate at cold joints. For Class 1a dwellings, the NCC requires external walls to resist moisture penetration so internal spaces remain dry, safe, and healthy.
In other words, you can’t just print a wall and call it weatherproof.
Why Weatherproofing is Different for 3DCP Walls
Unlike traditional blockwork or brick veneer, 3DCP homes:
- Often use a single skin wall with integrated voids or infill rather than separate cladding and cavity systems.
- May have visible layer lines that, without treatment, can create capillary paths for water ingress.
- Can have unconventional jointing at window and door openings, requiring customised flashing solutions.
The Solution
A weatherproof 3DCP wall system needs to satisfy more than the basics. For NCC compliance, we recommended a strategy that addresses surface porosity, joint sealing, and water management detailing:
- Surface Protection (Barrier Layer)
- Integral Waterproofing (Within the Mix)
- Joint and Opening Detailing
- Cavity or Drainage Gap
- Rising Damp Prevention
Thoroughly researching the scientific papers on this technology, assessing various case studies, Australian Standards and deep diving into industry publications allowed us to provide a tailored Performance Solution that layer by layer supports the use of this incredible technology that will become more mainstream as its benefits are realised.
Why This Matters
Bottom line:
The Deemed to Satisfy (DTS) provisions in the Building Code of Australia is a reactive set of rules and will always be catching up to modern or bespoke technological advancements in the building space. Performance Solutions Australia can help satisfy the Building Code of Australia and enable new and emerging technologies to be used in exciting ways for Builders, Designers and Architects.