Bison VCL Variable

Product description
Bison VCL Variable is a UV stabilized polyester based membrane used on the warm side of the wall or roof construction. The VCL is used to airproof and to control water vapor. The VCL enables a so-called bidirectional vapor transport. A certain steam flow is permanently ensured outwards in the structure, but also inwards. This increases the ability to dry out while reducing the risk of harmful condensation and moisture accumulation.

Variable vapor density
During the summer, the membrane opens at higher humidity, increasing the possibility of inward drying. In winter, the function is reversed and the membrane closes. This means that moisture migration into the structure is prevented. The variable vapor density of the VCL leads to an efficient flow of vapor in the structure.

Use
Bison VCL Variable works well with Bison House Wrap / House Wrap Pro/100 and also with Bison Permeable Roofing Underlay / Permeable Roofing Underlay 175. The vapor control layer can be used in most types of construction and in sloping roof constructions, for example, the air gap between the insulation and the tongued and grooved board can be eliminated. The properties are particularly suitable for, for example, holiday homes / seasonal accommodation where heating takes place periodically. The vapor control layer is also ideal for structures insulated with organic materials and even in old houses where air and vapor barriers are not suitable. The vapor control layer should not be used in structures with permanently high humidity (e.g. bathhouses)

Storage
Bison VCL Variable should be stored in unopened packaging or in such a way that it is not exposed to moisture, UV light and heat.