NCC Version:
2022 Volume Two – Building Code of Australia (Class 1 and 10 buildings).
Area of NCC Requirements:
- Section H: Damp and weatherproofing
- Relevant Performance Requirements:
- H2P1: Rainwater management
- H2P2: Weatherproofing
- H2P3: Rising damp
Problem:
The project involves a planter box concrete upstand as part of a first-floor external wall without the standard 100mm minimum set-down. Without this set-down, there’s an increased risk of surface water penetrating the building envelope, leading to potential water damage, rising damp, and Mould growth, thereby compromising the building’s durability and occupant health.
Solution:
A Performance Solution was developed using a Waterproofing Membrane (MAPEI Mapelastic Smart) over a sloped screed, combined with a 170mm x 40mm MEGAFLO Green Panel drainage system and a Filter wrap geotextile layer. This system, installed according to AS 4654.2 and manufacturer guidelines, was assessed through expert judgement to ensure it meets NCC H2P2 weatherproofing requirements.
Finalised Report:
The final report concludes that the waterproofing and drainage design, when installed per the specified Australian Standards and manufacturer guidelines, meets the NCC 2022 Performance Requirements. Expert assessment confirmed that the system effectively manages water and prevents moisture ingress, satisfying the acceptance criteria and ensuring the planter box integration is compliant.