When warm, moist air interacts with cooler surfaces, the condensation is produced – in other words, it turns into water. This happens because the air, which cooled down from the surface cannot maintain the moisture, as the warm air does. Anti-condensation films help to reduce the amount of condensation in the room.
Anti-condensation films, also called waterproofing films, are used to protect all types of roof surfaces. Anti-condensation films are usually used for sloping roofs when insulation for cold roofs is not used as the anti-condensation film has low permeability to steam in comparison with the diffusion film, but it is particularly resistant to tearing.
Let’s start with what types of roof films are there. There are 3 types of roof films: anti-condensation film (membranes), diffusion film (membranes) and steam insulation film. The anti-condensation roof film costs from 0.30 to 0.50 euro cents per square. It is designed for installation on the rafters of the uninsulated lofts. This film is technologically outdated, it has long been replaced by a much more advanced product – the diffusion film. The price of the diffusion film is practically the same as the price of the anti-condensation membrane, but according to its characteristics it is much more advanced. The anti-condensation film does not let the steam go through from the bottom, and the diffusion membrane lets it go through – thus, the diffusion film allows the roof structure “to breathe”. What is more, the diffusion membrane protects the roof structure from condensation that forms under the roof. The price of the diffusion film ranges from 0.30 to 1.5 euro per square. The range of diffusion films is very wide, although their names are similar, but the technical parameters are very different. Therefore, there is a risk of using a diffusion film intended for walls while carrying out the roof installation. When choosing a roof film, avoid double-layer diffusion films, because they are intended specifically for walls. It is not advisable to buy the thinnest membranes. It is not recommended to choose films which are thinner than 120 microns because it is very easy to tear. The steam insulation films are designed to protect the insulation layer from the steam coming from the premises. The price of steam insulation films ranges from 0.13 to 0.5 cents per square. The use of such films is very simple: the most important thing is to seal the junctions with adhesive tape in order to ensure that the film performs its functions properly.