Wall Cladding- Class O??

[jakespop]

Has anyone any information on whether "Altro Whiterock" satisfies Class O surface spread of flame rating? The information I have is that it satisfies Clsss 1 of BS 476 and Class O of BS 476 Part 6. What is difference?

[Tom Sutton]

From what I understand jake Class "O" is a definition which only applies to Building Regulations (ADB)

Appendix A Para 13

The highest National product performance classification for lining materials is Class 0. This is achieved if a material or the surface of a composite product is either:

a. composed throughout of materials of limited combustibility; or

b. a Class 1 material which has a fire propagation index (I) of not more than 12 and sub-index (i1) of not more than 6.

Note: Class 0 is not a classification identified in any British Standard test.


To check if its class O then you will require the test results.