The standards DIN 18550-1 (edition 2014-12) and DIN 18550-2 (edition 2015-06) have replaced the pre-standard DIN V 18550 (edition 2005-04). The division into plaster mortar groups PI to PIV, which is regulated in the previous standard , is referred to as "former" in the new regulations, i.e. it is officially no longer existing. The same applies to the classification into P Org 1 and P Org 2 for plasters with organic binders.
Nevertheless, these classifications are still relevant for construction practice, as literature and product approvals still refer to them.
In the old DIN V 18550, plaster mortars are divided into four groups according to their material:
PI Lime mortar
PII Lime cement mortar
PIII cement mortar
PIV gypsum mortar
Tables 2 (Exterior plasters) and 3 (Interior plasters) of the old DIN V 18550 specify which mortar group is suitable for which applications (exterior plasters: without special requirements/ water-retardant/ water-repellent/ basement wall exterior plaster/ exterior plinth plaster; Interior plasters: usual use/damp rooms, suitable as a base or top plaster.
The designations are still in use, even though DIN EN 998-1 contains a system in which a distinction is made according to the properties or the intended use of the plaster mortar.
Plasters with organic binders (synthetic resin plasters) are also divided into the groups
P Org 1 suitable as exterior and interior plaster and
P Org 2 only suitable as interior plaster
in the old DIN V 18550.
Source: bauwion
