Cement mortar or lime mortar?

Advantages and disadvantages of cement mortar

• Cement mortar is suitable for all indoor and outdoor areas. It can be used for basement masonry or for base plaster.
• The somewhat difficult processing is a disadvantage. That's why you usually add a little lime mortar. Cement mortar also absorbs little moisture and therefore quickly becomes brittle. The water vapor permeability is also difficult.
• The advantages of cement mortar: It is weather-resistant and frost-proof. Cement mortar is also characterized by good adhesion. Cement mortar also absorbs bumps and pressure very well.
• The processing is also very easy: the mortar is mixed with water and applied to the masonry with a spatula. However, the plaster should not be applied too firmly, as otherwise unsightly clods can form.

Lime mortar - the advantages and disadvantages

• Lime mortar is not suitable for outdoor use because it is sensitive to moisture. If the humidity is too high or if it rains, lime is converted into calcium bicarbonate. This is a completely harmless process and, at most, a minor blemish because it eliminates lime.


DIN 18550: Plaster - Notes

DIN standards (German Institute for Standardization) are managed by the ...

• Due to the large pores, there is a high level of air and moisture permeability. This has a positive effect on the growth of fungi, which is also disadvantageous.
• Lime mortar also has a long hardening and setting time.
• Advantages of the lime mortar are its elasticity and suppleness when used. In addition, lime mortar is climate-regulating due to its porosity.
• Due to the positive property of water vapor permeability and the capillary suction capacity, lime plaster is also suitable as a base coat for heavier wallpapers.

Avoid skin and eye contact when applying mortar because it has an alkaline effect when it is wet.