TS EN 14909

TS EN 14909 is a European standard for the definitions, characteristics and conformity assessment framework of flexible plastic and rubber sheets intended for use as damp proof courses in buildings. It provides a technical basis for understanding how these products are identified, what performance-related properties are considered, and how compliance with the standard is assessed.

What a damp proof course does in building construction

A damp proof course is used to limit the upward movement of moisture through building elements such as walls and floors. Flexible sheets made from plastics or rubber are chosen for this function because they combine impermeability with the ability to accommodate installation details and surface irregularities. In practice, flexibility matters because the sheet must be handled, lapped and integrated into joints and transitions without losing its sealing effectiveness.

Technical scope covered by the standard

The standard specifies the characteristics of these sheets, their test methods and the basis for evaluating conformity to its requirements. From a general technical standpoint, this means the document is concerned not only with the material form of the product, but also with the properties that influence its performance in service. Characteristics such as thickness, mechanical behavior and resistance to water-related exposure are central to how such products are specified and assessed for building use.

It also excludes related products such as preformed cavity trays, coping and flashings. That distinction is important because these items serve closely related moisture-management functions but differ in geometry, installation details and performance expectations. TS EN 14909 is therefore focused specifically on flexible plastic and rubber damp proof course sheets rather than on all waterproofing accessories used in masonry or envelope detailing.