In the event that your decision was the complete reconstruction of the floor screed, you first need to prepare a mixture for filling the floor in compliance with the proportion. Then this mixture must be poured along the floor, throughout its perimeter, if you have a large room, then you need to divide it into sites and pour it in parts. When breaking the floor, not segments, the mixture is poured into them separately, as a result, a formed single space is obtained. The repair of the floor screed is completed by grouting the base.