There are no permitted routes under a floor or above a ceiling.
Are you saying that the whole cable is plastered over, or just where it runs under or through a joist?
There are special plates that you can obtain from builders merchants or electrical wholesalers that will prevent the cable being pierced by nails or screws.
Whole cable is plastered, cable is attached to underside of the joists in the ceiling, then plastered over. I chased into the ceiling.