What is AS/NZS 4859.1?
AS/NZS 4859.1 is a standard that outlines the general criteria and technical provisions of thermal insulation materials for buildings.
How is it Changing?
The updated AS/NZS 4859.1:2018 standard will see changes introduced to the way the product is tested and how thermal performance (R-value) is calculated and declared, affecting bulk, reflective foil and rigid foam insulations.
The biggest changes within the amended standard AS/NZS 4859.1:2018 are to do with thermal testing and formal declarations of performance labelling.
Thermal Testing:
- A statistical assessment of at least 10 test results is required for each material assessed under the standard.
- This statistical assessment shall determine the R-value and thermal conductivity for the products tested from the statistically adjusted mean values representing a 50% fractile with 90% confidence for a one-sided tolerance interval. To be expressed as R50/90 or λ50/90.
- The same statistical assessment is applicable for all insulation materials, except for vacuum insulation panels.
- The adopted heat aging methods required for determination of long-term thermal values for rigid foam insulation materials are now aligned with European standards and are more stringent than before to more accurately represent long term in-situ performance:
- Phenolic foam (PF) insulation is now included with an accelerated aging requirement for aging for 14 days at 110oC, or for 175 days at 70oC, or aged using a prescribed slicing method.
- Polyisocyanurate (PIR) and Polyurethane (PUR) insulations are now required to be heat aged for 175 days at 70oC, or aged using a fixed increment method.
- Extruded Polystyrene (XPS) insulation is now required to be aged for up to 90 days, either sliced or unsliced, at 23oC, depending on product thickness and composition, i.e. whether faced or unfaced with foil.
- Expanded Polystyrene (EPS) is not required to be aged before testing.
- Manufacturers shall prepare a thermal value summary report which includes the product label details, including statement of conformance with the standard, and the statistical calculation of R50/90.
Thermal Declarations and Labelling:
- The ‘Declared R-value’ or ‘Declared λ-Value’ shall not be higher or lower than the R50/90 or λ50/90 respectively.
- Additional requirements for labelling are:
- Location of the manufacturing plant
- The relevant temperature for the declared thermal values (23oC for Australia and 15oC for New Zealand) must be consistently applied across the relevant markets.
- It should be noted that Total R-values are no longer acceptable for product labelling.
How will this Impact the Industry?
With the AS/NZS 4859.1:2018 introducing significant changes to product testing and labelling, the insulation market in Australia will see a change to product R-Values being declared and advertised in data sheets. The new thermal testing requirements are more stringent, meaning that the declared product R-values will decrease across the insulation product offering.
Specifiers and builders need to be vigilant and make sure that products they are specifying, and buying, are abiding by the newly amended standard.
If the manufacturers and suppliers aren’t following the new standard, it might mean that the advertised thermal values are not matching the actual values of the product in the market. This will affect the thermal performance of the finished building and in some cases might make it fall short of the minimal required thermal performance under the NCC.
For more assistance with the NCC 2019 changes regarding thermal insulation, contact our Technical Services team on 1300 247 235 or email technical@kingspaninsulation.com.au
