It is important to choose the right insulation for each building application and where applicable (e.g. BCA requirements) the minimum energy efficiency, acoustic ratings, fire and safety requirements.
There are many types of building materials available for use as thermal and acoustic insulation. Most have distinctive appearances, unique characteristics and differing performance levels - and as such are measured and tested differently for BCA compliance.
ASINZS 4859.1 2002 Materials for thermal insulation of buildings Part 1 : General criteria and technical provisions. This is the foundation insulation Standard and is called up in the BCA.
The Standard has:
- categories by type of Insulation (e.g. low-density fibrous batts and blankets, loose fill insulations, reflective membranes)- Different sampling and standard test methods and for each insulation type.
- Performance criteria (e.g. for blankets and balls a 10% shortfall in thickness could result in 5% loss in thermal performance, loose
- Fill cellulose density and thickness coverage requires consistency to meet thermal performance claims, and dust or air leakage will reduce thermal performance of reflective foil insulation).
- Performance claims guidelines by type of insulation (e.g. Material R for batts and loose fill, Total R for foil).
- Required labelling, product disclosures and safety information to comply with this Standard.
- AS/NZS 4200.1 1994.1 'Pliable building membranes and underlay’s - Material" is relevant for reflective insulation materials and is cross referenced in AS/NZS 4859.1
AS/NZS 4BS9.1 DOES NOT cover insulation fire properties by type. The main reference fire performance tests are AS1530.1 non combustibility (the most stringent test); AS1530.2 - surface fire performance for facings and foils, and As1530.3 general indices for batts and loose fill.
In order to demonstrate compliance with AS/NZS 4BS9.1, testing must be performed by a recognised laboratory relevant to this Standard. Test results are valid for 5 years. In recent times noncompliance with this requirement has increased. A provision of this Standard is that copies of test reports, and where required, calculation reports, are to be made available on request for verification.
Correct installation is all-Important to achieving the claimed thermal performance.
Installing Insulation can be classified into distinct sections:
1. Bulk insulation
b. Loose fill materials (e.g. macerated paper (cellulose fibre), blown glasswool and granulated Rockwool).a. Batts and blankets (e.g. glasswool, Rockwool, polyester, sheep wool).
2. Reflective foils
a. Reflective Insulations (e.g. single and double sided fall laminates, bubble wrap, foam foil-faced wrap).
a. Rigid Boards.
b. Foam insulation.
Insulation Installation standards for bulk insulations
AS 3999 '992 Thermal insulation of dwellings – Bulk insulation installation requirements is the current Standard for bulk insulation installations.
Provisions in this standard cover the importance of:
- Site Inspections prior to proceeding wit h Installation.
- Perimeter edge restraints and protective barriers for down lights, flues, fans etc. for loose fill insulations.
- Minimum clearances from ceiling penetrations such as flues, fans and downlights.
- Some jurisdictions also refer to provisions in AS/NZS 3000 2007 Clause 4.5.23 for installation of insulation around down lights. Insulations that cannot satisfy criteria of
- Sub-sections (a), (b) or (c) are required to meet the default provisions of subsection (d). (Refer to manufacturers as compliance differs by insulation type).
- Electric cabling and separators from insulation in stated circumstances.
- Snug fitting, butted to timbers and joists. Non-compliance to insulation gaps in A53999 can cause significant losses in the thermal efficiency of insulation. This has been recognised in the BCA where added insulation requirements are included in a calibrated table of adjustments for the % of uninsulated ceiling area. Refer to BCA tables Vol 1 : J1.3b and Vol 2: 184.108.40.206b