Water ingress around windows remains one of the most common (and costly) defects in residential construction—especially in lightweight cladding systems where the external skin provides limited moisture protection. Correct flashing and installation are critical.
Standards to Remember
Under AS 2047, windows must be installed so they perform as tested.
Importantly, Clause 7.2.1 (General) notes that “window manufacturers’ installation procedures may need to be followed in particular installations.”
This means manufacturer instructions aren’t optional—they form part of compliance when the installation cannot be performed in accordance with the Standandard.
Lightweight Cladding Risks
Systems such as FC sheets, Axon, Rendered Foam and other panel products require:
Generic NCC or AS details will not always cover these requirements.
Where Standards Don’t Provide Detail
Situations like high-exposure designs, zero eaves, BAL zones, and proprietary wall systems often fall outside NCC/AS prescriptive guidance. In these cases, builders must default to the window and cladding manufacturer’s installation details to maintain weatherproofing performance.
Key Message
Correct flashing is essential. Combine:
to ensure windows perform as intended and to avoid future moisture-related defects.
