Laying of pipes through grooved screed

Hello everyone,

my electrician has finally started the work, but I'm not sure if what he is doing with the screed is really great. It is an old building from the 60s with about 4cm thick floating screed.

To get past the chimney, the electrician chiseled several centimeters off the screed along the chimney wall. I think that is still somewhat okay, but now he is filling these slots with screed without an expansion joint to the adjacent wall. He laid NYM cable. Shouldn't it be at least NYY? Can a Cat7 cable withstand this type of installation?

To get past a room entrance door, he slit the screed again and laid a cable across the door threshold area, instead of going around the door frame above. That can't be good for the NYM cable if people keep stepping on it... here too, I am worried about the movement of the screed. The more I think about it, the less I want such a cable in the door threshold. That can't be right.

For the ceiling lamps, the electrician plans to slit the screed of the floor above and drill directly down. He has already drilled and the NYM cable is still lying on the screed without slots. Is this installation in the screed acceptable, or do I have to urgently stop this procedure before he further damages the (thin?) screed tomorrow?

Sorry that I can only provide the photos tomorrow.

Best regards
Tassimat

NYM is sufficient for installation in screed or plaster. NYY is not necessary.

CAT should of course be installed in a protective conduit.

Sheathed cables may also be installed in screed without protective conduit. This installation method can be found in VDE 0100-520, Table 52H under reference No. 52. According to Table 9 in DIN VDE 0298-4, reference installation method C should be chosen to determine the current-carrying capacity. However, it should be noted that saving on installation conduit is associated with a reduction in mechanical robustness. Installing cables and conductors in installation conduit with at least classification code 2 according to DIN 50086 (VDE 0605) can be considered mechanically protected according to subsection 522.6.1. The executing professional must assess whether the mechanical protection undoubtedly provided also by the floor is sufficient. If sheathed cables are installed in conduits (reference No. 5A), this is associated with a reduction in current-carrying capacity.

Wow, thank you. I did not expect such a detailed answer including the norm. The mechanical load capacity is still my biggest concern. I would need to be able to restore the currently partially filled expansion joint of the screed. Photos are coming soon, I have to attend an appointment at work first.

Photos definitely do not forget.

Here are a few photos.

To mechanically stress the cables there, you would already have to hit the slot quite precisely. I wouldn't see that as so critical.

What rather catches my eye is the missing airtight lower connection of the window (Bild 1)!