There are holes of various shapes in hollow bricks, due to which their thermal conductivity decreases. Therefore, the walls are made thinner – up to 1.3 meters. Hollow brick, as a rule, is always used for faces facing, as it is easier. Hollow porous brick is the most “warm” brick. He, like a hollow brick, has holes, but unlike it has a different structure of the material. In the manufacture of porous bricks, special mineral or organic additives fall into clay, which form microscopic closed pores when firing.