GN87 Rooflights and Roof Windows on Flat Roofs

Rooflights and roof windows are important features of many flat roofs, providing natural daylight, ventilation, smoke control or access. However, the junction between the roof waterproofing and the rooflight or roof-window assembly is also a common area of weakness. This guidance, created jointly by the National Federation of Roofing Contractors (NFRC), the Liquid Roofing and Waterproofing Association (LRWA), the Rooflight Association (RA) and the Single Ply Roofing Association (SPRA), offers practical advice on designing and installing these vital junctions.