3.4. Optimum mortars based on EU standards for rendering, plastering
and masonry
High compressive strength is less critical when mortars are
used for masonry. The relevant EU standard specifies that type
CS III mortars must have a compressive strength greater than
3.5 MPa to be used for rendering and plastering [54]. Therefore
mortars containing up to 20% PSA, using either powdered or
ground EPS are suitable for type CS III rendering and plastering
application. However, type CS II mortars must have compressive
strength of between 1.5 and 5.0 MPa. Mortars with up to 30%
PSA using powdered EPS and up to 20% PSA with ground EPS are
appropriate (Table 4). Type CS I mortars must have compressive