2021 NCC Seminars: Is this group number test certificate ok?

Is this group number test ok? I've got this wall lining or ceiling lining, and C1.10 has sent me to spec C1.10 Clause 4, and we need to have a smoke growth rate index not more than a hundred, or an average specific extinction area less than 250 metre squared per kilo, and I needed to meet a particular group number. And that's okay.

I've gone to the manufacturer's website, I've downloaded the certificate, and all the values check out. That's all I need to do, right? Wrong. Because this is one of those occasions where the NCC is interested in how those results were found.

This is the start of Spec C1.10 Clause 4. Subclause sets out the values you need to achieve, and Table 3 lists the various classifications, whether the room is sprinklered or not, and then provides a group number for that particular application. What I want to show you today is subclause . Yes, we need to know what the group number is, but we also need to know how. Well, the NCC is interested in how that was found. You must determine your group number in accordance with AS 5637.1.

Now, some of you may be saying: "Well, that's okay. That's the test standard, is it not? 5637.1 would be the test standard, which contains the test for calculating the group number." Well, no. 5637.1 is a signpost standard. It doesn't have any test procedures in it, but what it does is send you to our other standards, either AS/ISO 9705 for the room corner test, or the cone calorimeter test, that's per AS/NZS 3837 or ISO 5660-1. AS 5637.1 sends you to either of these tests.

Now the room corner test, you need to build a room 3.6 by 3.6 by 2.4, so about bedroom size. The walls and ceiling must be made from the material that you're testing. Heat is applied at the corner, a fire starts, and data is recorded. This is a full-scale test. It's a very expensive and involved test. Now the cone calorimeter test, it's a small scale test. You take a sample, 100 millimetres by 100 millimetres, place it in the machine, heat's supplied by a cone shaped heater.

That's why it's called the cone calorimeter test. The material reacts, and the data is recorded. Now for some materials, it's possible to use this data to predict how well the material will perform in a room corner test. And of course, being a small-scale test, it's much quicker and much cheaper to use this method.

The cone calorimeter isn't suitable for all materials, and that's where AS 5637.1 comes in. It sets out the criteria for materials that can use the cone calorimeter method, and some are listed here on the right. And if you don't meet those criteria, 5637.1 sends you to the room corner test, the expensive one.

So when you get a test report for wall linings and ceiling linings, not only do you have to check the what, that is, what the results are. You also need to check the how, how those test results were obtained. Was it done in accordance of AS 5637.1? We have an article about this on our website.

It's in ABCB Connect, and it's called "The what and how of fire hazard properties for wall and ceiling linings." It's on our website, abcb.gov.au, and I recommend that to you.

Is this group number test certificate okay? Well, it is if it's carried out in accordance with AS 5637.1.