Absolutely open... and optimal sealing

Roof and façade membranes must meet high tightness requirements for protection from driven rain and water. At the same time, they should also be highly permeable to allow moisture to dry and evaporate quickly and reliably from the structural component to the outside.

The previously available microporous membranes could fulfil these requirements only to a limited extent. New, moisture-activated membranes with a non-porous, monolithic function film offer significantly higher protection levels for structural components.

Conventional reliability - micropores

Mikroporöse Bahn Bild

Microporous membrane: little protection against rainwater

Conventional PP membranes with micropores only protect against water from the outside when the surface tension of the drops makes them too large to pass through the pores of the membrane. However, in the case of driving rain or when wood components or solvents lower the surface tension, considerable amounts of water may penetrate the insulation and cause structural damage and foster the growth of mould and mildew.

Magnification of a conventional roof membrane. The PP film is stretched and calcium carbonate is added during production. This creates holes in the material.

Mikroporöse Bahn Grafik

Microporous membranes become more diffusion-tight

These microporous membranes must transport water vapour through tiny holes to the outside. This moisture transport is a passive process, which only works when a relatively high partial vapour pressure gradient is present.
In modern, highly insulated structures, this is difficult to achieve. Another disadvantage arises when a lot of vapour must escape. This may lead to a moisture film forming on the inside of the membrane. The result is that the membrane becomes denser, the structure does not dry effectively, and damage may occur. If a film of moisture freezes in the winter, a vapour barrier effect may even be created.

Absolute permeability and maximum sealing: Monolithic SOLITEX membrane

Porenfreie Bahn Bild

Pore-free membrane: high component protection

Pore-free membranes provide protection against driving rain in particular. Since their membrane functions without pores, even high impact speeds or reduced surface tension of water droplets are not a problem.
These monolithic membranes transport moisture to the outside - the more moisture is present, the faster the transport speed. Their diffusion resistance decreases. Only a minimal partial vapour pressure gradient is required for the transport.

Same microscopic magnification of a monolithic, non-porous SOLITEX membrane.

Porenfreie Bahn, aktiver Feuchtetransport

Pore-free membrane: active moisture transport

The result is that non-porous, monolithic membranes with moisture-activated functional film deliver a high level of reliable protection from outside moisture for structural components while maintaining consistent diffusion-openness at the same time.

  • Maximum protection against driving rain, water column up to 10 000 mm
  • Active moisture transport, minimum vapour partial pressure gradient required
  • Wet membrane becomes more open to diffusion
  • No tent effect & can be used as a temporary covering