30 Jan 2023

Updated Guidance Note: Ponding on Flat Roofs

GN12, Ponding on Flat Roofs, has been reviewed and updated.

Guidance Note 12 (GN12) Ponding on Flat Roofs has been reviewed and updated. The guidance is specifically about flat roofs with exposed coverings. As well as a general overview on the topic, the guidance also details the issues caused by ponding and considerations to avoid excessive ponding.