In the case of screeds on separation layers in accordance with DIN 18560-4 and screeds/heating screeds on insulation layers in accordance with DIN 18560-2, edge joints must be made for all rising components (e.g. walls, columns, installations, door frames). These must allow all expected movements of the screed panes, e.g. due to drying out of the screed or thermal length changes due to solar radiation or heating. In the case of screeds/heated screeds on insulating layers, the edge strips must also ensure that the screed pane is acoustically decoupled from all adjacent components. In order to enable the movement of at least 5 mm required in accordance with DIN 18560-2 for heated screeds, a joint width of at least 10 mm is required. This width is also required for mastic asphalt screeds that are to be covered with hard surfaces (e.g. parquet or tiles).
Especially for larger rooms and for screed surfaces without movement joints within the screed surface, a calculation of the required joint width is strongly recommended, as this can also be significantly more than the minimum size according to DIN. Information on how to calculate the required width of edge joints for floating screeds and screeds on a separation layer can be found in the following >link to the Institute for Building Materials Testing and Flooring Research (IBF).
According to DIN 18560-2, the plastering of walls must always be carried out before laying the insulation layers for the screed.
1 Shell wall
2 Wall plaster
3 Covering
4 Screed
5 Insulation layer
6 Load-bearing substrate (raw ceiling)
Schematic representation, without connection details and separation layers!
Source: bauwion
