Before moisture is introduced into the building as a result of plastering or installing screed, the insulation should be installed into the spaces between the rafters and the vapour retarder layer should be sealed in an airtight manner.
The building should initially not be ventilated to allow the screed to harden without deformation or the formation of cracks. Depending on the type of screed used, the removal of building moisture can generally be initiated after just three days. This should then be done in a systematic, effective manner.
However, it is often the case that this moisture is not dried using drying equipment and is not removed by ventilation. If drying and ventilation are not carried out, a “tropical climate” can occur inside the building that can soon have a negative impact on a range of building components.
For this reason, the issue of increased moisture during the construction phase is now also dealt with in standards: for example, DIN 4108-7 states that increased construction moisture is to be removed from buildings and/or that drying equipment is required.