Despite a lack of regulatory guidelines on the management of condensation in Australia, the Australian Building Codes Board (ABCB) has warned that blindly following international standards is not the solution.
The warning is included in the updated Condensation in Buildings Handbook released by the ABCB this week.
It covers condensation requirements and new provisions within the National Construction Code (NCC) 2019.
The handbook includes key Australian and international standards as they relate to condensation. However, there is no Australian Standard that solely deals with the management of condensation.
Instead there are standards dealing with roofing, wall cladding, insulation, masonry, and bushfire management.
These are matters that all affect how designers and builders deal with issues that affect condensation.
“There are international standards that address condensation specifically. These standards are aimed at European climate zones and often use very different construction practices not common in Australia,” the handbook warns. “For these reasons designers need to be wary of blindly following International Standards.”
Condensation can occur in all types of buildings, largely due to poor design or inappropriate use of materials and, once present, it is difficult to eliminate.
There are a number of international standards available that provide details on moisture control and condensation risk assessment in buildings and building envelopes.
The assessment methods are mostly based on multi-variable calculations and enacted through computer simulation tools.
ANSI/ASHRAE Standard 160-2016 Criteria for Moisture-Control Design Analysis in Buildings sets minimum acceptable criteria for analytical tools capable of analysing thermal and moisture transfer and conditions in building envelope components.
The quantified performance evaluation criteria provided in the standard include measures for conditions affecting mould growth and corrosion of the various materials and surfaces within the building or the building envelope, excluding the exterior surface of the building.
The ANSI/ASHRAE Standard 160 cites two other ASHRAE Standards as references:
• ASHRAE Standard 55-2013, Thermal Environmental Conditions for Human Occupancy;
• ASHRAE Standard 62.2-2013, Ventilation and Acceptable Indoor Air Quality in Low-Rise Residential Buildings.
Both of the referenced standards have been updated since the release of ANSI/ASHRAE Standard 160-2016.
ASHRAE Standard 55-2017 and ASHRAE Standard 62.2-2016 are the current versions.
The ABCB handbook was first published in 2011, revised in 2014 and minor editorial changes were made in 2016. It was updated in 2019 due to new condensation provisions introduced in the NCC 2019.