I read Austin Williams' interesting article on flat roofing membranes (AJ 5.7.01) and wish to point out that although the British Standards quoted are indeed elderly, specifiers can rely on the British Board of Agrement's certificates in this and indeed many other product areas where no BS exists.
The list of BBA-approved membranes (available via our website www. bbacerts. co. uk) is extensive and each certificate details installation methods, compliance with the relevant Building Regulations and, of course, as is the case with all BBA certificates, durability.
There are also developments at European level - not just European Standards but also European Technical Approvals - a kind of pan-European BBA Certificate. ETAs will be available for mechanically fastened and liquid applied membranes during the next two to three years.
Alan Thomas, British Board of Agrement