Publication of the CSTB guide "Flexible underlayment membranes"

Flexible underlayment membranes help protect pitched roofs made of small elements (primarily tiles and slates). They prevent the penetration of powdery snow, soot, or dust, but they also have other functions such as protecting insulation and improving airtightness, which are detailed in this guide.

The practical guide "Flexible underlayment screens" presents the different types of screens and the criteria for choosing products.

He details and illustrates the implementation by answering the following questions:

What are the principles of safe implementation?
How to manage ventilation (positions and dimensions of air blades and ventilation openings)?
How to achieve the overlaps, the counter-battens?

Regarding the treatment of singular points of the roof, the author presents numerous examples for implementation: connection to the sewer, ridge, ventilation outlets, edges, valleys, sealing around the roof window and chimney, etc.

A final chapter sets out recommendations for screen maintenance and troubleshooting.

This new edition takes into account the implementation recommendations of NF DTU 40.29 and the application of the certification framework.

This guide will be of interest to all professionals who prescribe or install under-roof screens (project owners, architects, design offices, building companies).

This edition has been updated by Marc AUGEAI, Rapporteur of GS 5.1 "Roofing Products and Processes" at the Building Envelope Directorate of CSTB and Valérie WESIERSKI, Technical Director of Sloping Roofs at BMI Group.

To find out more, consult the extract from the guide and order it: CSTBoutique