1NF bricks can be used in all types of walls: structural, load-bearing, curtain and partition walls. Masonry on ordinary mortar with filled vertical and horizontal joints. After the introduction of the Silka E series, they are used as external layers in three-layer walls and when there is a need to leave the wall from a block in lime-sand without plaster, finished only with grouting or painted . Smooth side surfaces. The product has approval documents for use.