“Marry in haste, repent at leisure”, as the saying goes. This case is not quite so dramatic but PAS 121 (in common with most PAS) was written in haste and it shows.
At last though we have a replacement (in fact 2 replacements) in the form of BS 8524-1 and BS 8524-2, both published last month. These have been developed through the full BSI process and are much better.
Of course it will take a while for manufacturers to test and certify their products to part 1 (the product standard), but although its scope states that its use is limited to curtains complying with part 1, part 2 (the application standard), can be used right away.
One major change is that the “insulating zone” concept, an unfortunate innovation in PAS 121, has been dropped and replaced by use of conventional radiation data. Of course this data is not always easy to use, so for protection of means of escape simple tables have been developed.
Otherwise the selection tables have been simplified and a lot of loose ends tied up.
Within the product standard there is (as seems inevitable these days) more testing, but the test requirements are better thought out and developed, with less room for interpretation.
One frustration with the standard (unfortunately enforced by the prEN 16034 European standard) is that when a fire curtain directly replaces a fire door the above standard cannot apply; the European fire door standard applies instead. This is fine for the actual fire test, but there is so much more to BS 8524 which the fire door standards do not address.
Overall, though, a good step forward.
If you would like more information on fire and smoke curtains and their respective legislation, Paul Compton is holding a webinar on the subject on the 14th June. Please click the link below for more information and to register.
Paul is a Technical Director for Colt, experienced in smoke control, HVAC, solar shading and louvre systems.