Unenclosed Shower
Secondary floor waste alternatives
NCC 2016, Volume 2
Area of NCC Requirements:
- Part 3.8 Health and Amenity
- Part 3.8.1 Wet Areas and External Waterproofing
- Clause 3.8.1.2 Wet Areas
- Relevant Objectives: O2.4.1 Wet areas
- Functional Statements: F2.4.1 Wet areas
- Performance Requirements: P2.4.1 Wet areas
The Challenge
Timber floors look fantastic, feel warm underfoot, and suit heritage and high-end residential design. The compliance problem is that bathrooms and ensuites are high-moisture environments, and solid timber is vulnerable to swelling, warping, joint movement, and long-term deterioration if moisture gets into or beneath the boards.
Because solid timber flooring is not a typical Deemed-to-Satisfy (DTS) solution for wet areas under NCC 2016, the proposal raised legitimate concerns about water resistance, durability, hygiene, and whether the wet areas would maintain safe and healthy internal conditions over time.
A performance-based solution was therefore required to demonstrate that the timber floor system could achieve the same outcomes intended by Clause 3.8.1.2.
What This Really Means
Wet area compliance is outcome-based. The NCC’s objective is to ensure that wet areas resist moisture, remain durable, and do not create conditions that damage building elements or reduce occupant health and amenity.
When a non-traditional finish is proposed, the real question becomes whether the floor system can function like a wet-area floor should—resisting moisture exposure, maintaining integrity, and remaining serviceable throughout its life—rather than whether it matches a prescriptive material list.
The Solution
A performance-based assessment was undertaken to confirm that the proposed timber flooring system could satisfy the intent of O2.4.1, F2.4.1, and P2.4.1 under NCC 2016 Volume Two.
The assessment considered:
- Whether the flooring system resists moisture exposure in wet area conditions
- How the system manages water at the surface and reduces the risk of absorption at joints and interfaces
- Durability under repeated wetting, cleaning, and normal bathroom use
- Hygiene and whether the system avoids conditions conducive to microbial growth
- Installation controls and ongoing maintenance factors required to preserve performance
- Whether the overall outcome is equivalent to, or better than, a DTS wet-area floor finish
Rather than focusing on timber as a material in isolation, the assessment focused on the floor as a complete system and how it performs in service.
Why This Matters
The final report confirmed that the proposed wet area floor system satisfies the NCC 2016 performance intent for bathrooms and ensuites when installed and maintained in accordance with the assessed conditions. Despite departing from typical DTS expectations, the solution demonstrated an acceptable level of moisture resistance, durability, and long-term amenity.
This project shows how performance solutions can unlock design-driven material choices—like timber floors in wet areas—while still achieving the NCC’s required health and amenity outcomes.