Understand The Facts About Group Numbers
Just as the need to identify the correct Group Rating for your project is critical (see our article ‘What Group Rating do I need’ ), it is also vital to ensure that the product you select does in fact meet the rating requirements.
Standards Australia introduced into the BCA ‘AS5637.1 : 2015 – Determination of fire hazard properties – Wall and ceiling linings’ to help determine accurate group numbers, particularly around multi-layered and perforated products.
Under the Standard:
- Group Numbers can only be obtained when assessed to AS5637.
- Products which are multi-layered & perforated must be assessed to AS5637
- AS3837 (Cone Test) or AS9705 (Full Room Test) alone cannot be used to issue a Group Number.
Prior to the introduction of AS 5637, panels were often tested as a solid panel and were therefore achieving a Group 1 Rating. All perforated acoustic panels whether it is timber, plaster or fibre cement generally consist of multiple layers of materials glued together and they are perforated with holes or slots to achieve acoustic performance. Fire experts identified that multi-layered products with perforations can reduce the fire performance of a product, hence why AS 5637 was introduced.
Group Rating Certificate Tips
We have put together tips to help know what to look for when viewing your Group Rating certificate to ensure it exactly matches the product you want to specify.
1. Check to ensure the product has been assessed to AS5637
- Look for the Standard Number on the test certificate.
- Old certificates prior to 2015 may show a Group number but take note this has not assessed to the new standard. Customers are advice to seek clarification from their fire engineers if they can use old certificates.
2. Check that the test certificate is the same as the manufactured product.
- A test carried out on a SOLID MDF panel should not be used for an Acoustic Perforated Panel where there are multi-layer and perforations.
- For Example: An architect has specified: 12mm FR MDF timber veneer acoustic perforated panel with a 22% open air percentage. They have received a Group Rating Certificate for a panel that is 12mm FR MDF timber veneer solid panel. Therefore as it was tested as a SOLID panel, not a perforated panel – that certificate does not match their specified product, so is not acceptable to use.
3. Inspect the test certificates for the following information and make sure it matches your product:
- Product Code
- Material Type
- Material thicknesses
- Material Finish
- Material constructions
- Check all the materials, layers and perforations are clearly displayed
- Multiple layers of products are considered a system.
- Solid panel certificates do not include perforated or slotted variations using the same material.
4. Check the open area percentage on the certificate matches the open area percentage of the product you are specifying.
- Different open area percentages can also affect the fire rating achieved so important to ensure it is within the range that has been tested
5. Take caution when suppliers are claiming their products are FR certified
- Check what this means. FR could have a different meaning in different industries.
- Always ask for the Fire Test Certificates regardless of the claims.
- Example: some certificates like AS1530.3 will not provide a pass or fail and will only give you a set of results. Don’t be fooled to believe the marketing claims that the product is ‘certified to AS1530.3’. This is a misleading statement and widely used in the industry.
6. Find out what the exact Group number for your project is by reviewing against the BCA Wall & Ceiling Lining Materials table in NCC Specification C1.10.
- Atkar Group have introduced a Group Rating Calculator using the data from the above table to help your identify your Group Rating easier.
Group Rating certificates can be difficult to decipher, especially given all the recent changes. Most suppliers are doing the right thing and updating their Fire certificates to the new standards, however there are some that are still using old version. As the results can be disastrous if you get it wrong. If you are still in doubt speak please to an Atkar Group representative for assistance.
Atkar have also introduced our Wall & Ceiling Lining Material Group Rating Calculator, that helps you easily identify what Group Rating rating you need for your project – click here to check it out.
If you have any enquiries around Group Rating then please contact our Architectural Team on 03 9796 3333 or email@example.com