The concept of a zero fall (dead flat) roof is accepted in the UK, across Europe and around the world. For the UK and Europe there are a number of documents relevant to the specifier and waterproofing manufacturer. These include European Technical Approval ETAG 31, which reinforce the need for the architect and main contractor to consider the design and installation of the roof slab and drainage points, to avoid ponding and where necessary locate outlets at anticipated low points.
BBA Building Bulletin No. 4 provides further clarification on the specific requirements of a Zero Falls roof.
The simplest way to ensure a product is suitable for Zero Falls application is to look at a product BBA Certificate, which will clearly state if a product is suitable for Zero Falls applications.
For zero falls design advice please contact your local Radmat Area Technical Manager.