No more standard confusion

With reference to the article “Timber in the firing line” (TTJ October 28/November 4), there seems to be some confusion between the European Standard class B and the current British Standard classification.

Class 0 is an assessment of tests carried out under BS 476 parts 6 and 7, which comprise propagation and spread of flame. The indices of the results are taken into account for class 0 to be defined, which is a Building Regulation requirement and not a BS classification.

The European test EN 13823 is based on a full-scale “corner” test, where life-size product is subject to stringent examination. The idea is that this test will eventually supersede the old-fashioned BS tests that originated in the 1950s, which use only coupon-size test samples.

It is in the application of products where an alignment has been made between the two test methods. Details can be found in Approved Document B Fire Safety European Supplement 4.1(7.1) Table 10(ES). This table will refer to the requirement for wall and ceiling innings. Here it will define where European class D, C or B can be used, along with the corresponding British Standard Class 3 & 1 together with Building Regulations class 0.

Therefore, Stephen Cope is correct to say that class 0 has not be replaced by Euroclass B. However, it is worth pointing out that either class 0 or class B tested products can be contemplated for the same application.

Graham Osborne

Marketing manager

Sundeala Ltd