Electrical cable fixing/nail shot through bitumen welding membrane

Is it really allowed to damage the bitumen sheet during installation?

Regards Daniel

Do you have an alternative way to secure the pipes on the raw floor?

Yes, glue or something similar,
It somehow can't make any sense to damage the bitumen membrane.
How would it be done with the others?

I am a trained electrician and would have preferred to simply nail them down with OBO dowels, but our engineer advised against doing that. If the bitumen membrane is not damaged, there is no need to worry about whether it is permitted or harmful.

We then glued the pipes (including water pipes and supply/return for the heating control valve) to the bitumen membranes using strips of bitumen membrane. It was a lot of work, but it went quite well.
I would do it that way again.

So one should not do it?

Maybe a few points to think about:
- You can seal the nail holes again with bitumen mastic
- Is a bitumen membrane really necessary for a watertight (WU) slab?

Many slabs are poured today with WU concrete, where the bitumen membrane is more of a "we’ve always done it that way" approach.
It is even laid in WU basements, but what is it supposed to achieve there?