We discusses about it seldom that absorption through leaky concrete of substances harms it , the most well-known are different kinds of chlorides which cause irreversible losses causing corrosion of concrete and corrosion of steel , next alkali as well as fungus spores causing biological degradation of concrete.

In our long standing experience we met with concrete articles, which in short time after building covered themselves by every essences possible together with moss , and complaints were very expensive . It is so proper to apply suitable admixture to receive concrete with planned proprieties.
Designers think very often about sealed concrete and they have in their mind every kind of perpendicular and horizontal sealing ,and it is obvious that during the building obtainment of continuity of sealing in this way is enormously expensive, very difficult and time-consuming, therefore you should protect against results of break of this type of sealing applying simply sealed concrete.