ᐅ Cracks in the precast ceiling are likely to continue spreading.

Hello everyone!
Our house has precast concrete ceilings.
Some time ago, I noticed fine hairline cracks, approximately 0.1 to 0.2mm (0.004 to 0.008 inches) wide. These cracks run diagonally across the rooms and are several meters long.
Until now, I haven’t paid much attention to them.
However, today I noticed that these cracks seem to be shifting.
The joints between the slabs were filled with joint compound, and I could see that the cracks are reopening there.
We now have screed installed, and the heating program is nearly complete.
I’m wondering if I should get an expert to take a closer look.
What do you think?

Best regards

Up to 0.4 mm (0.016 inches) is not considered a defect if nothing special has been agreed upon.
Fleece on the ceiling, and that’s fine.

Every paint covers small cracks like these. Still, it is concerning where they come from.

This is not a cause for concern but completely normal. Color does not seal this.

Lumpi_LE schrieb:
This is not concerning but completely normal. Paint does not seal cracks.

Sorry, but what you call normal is not normal to me. And why shouldn’t paint seal cracks? Buy good quality paint, then it will work 🙂

Yes, if you have no idea and just talk without knowledge, you can certainly do that. You can google "crack width in concrete high-rise construction," and maybe someone will still invent crack-bridging paint... who knows.