As an example, one small case can be given from your own practice, the one that will move back the deadlines for more than one month. The walls and ceilings of this room are already ready for painting and gluing with wallpaper. And here suddenly the owner of this premises decides to unexpectedly install the floors not on the lags, but to pour a small screed. The layer is naturally decent, and it will gain the fortress and it will dry out at least 20 days later. All work after the filling was suspended for this period.