Airtightness sealing has a wide range of significant impacts on buildings. After all, air can flow through the building envelope in an undesired manner if the airtightness sealing is poor. Substances or energy can be transported in this way – this is referred to as convection.
This means that heat leaves the building in an undesired manner during the winter or enters in summertime.

A joint with a width of 1 mm and a length of 1 m in a building structure looks small, but has a major impact. The heat losses increase by a factor of 4.8. In addition, up to 0.8 litres of humidity can enter the building structure in a single day.
Scientific studies have shown that the thermal insulation performance can be reduced to just 20 per cent in the case of strong air flow (i.e. through leaks).
Alongside these heat flows, water that is present in the interior in the form of air humidity can enter into building components through leaks in the airtightness. In winter, the temperature in these building components falls. Condensation liquid can then form, which can lead to subsequent damage such as mould.
Unwelcome odours or harmful substances can also spread – and who wants to be able to smell what the neighbours are cooking?
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