Is there blue concrete in our wall?

[Nelax]

Hello!

I have just started renovating the new apartment and discovered that there is a blackish concrete hidden under the first two centimeters of plaster. After the concrete, there is a layer of wood, then plaster again.
I'm attaching some pictures so you can see how it looks.

Some questions:

• What do you think, is this blue concrete?
• If it is, is it dangerous to demolish?
• If it's dangerous to demolish, how should one demolish it safely?
• Is it dangerous to live in?

Grateful for answers

Best regards,
Johan

 

[Jan-Å]

Yes, it strongly reminds me of the kind of stone that our house is partially built from, so it's probably blåbetong. No, it's not dangerous to demolish if you ask me, we've both demolished walls and chiseled away tiles from such walls, but a dust mask is recommended. There might be safety regulations concerning this, but I've never checked, and none of the workers seem to care either. However, the dangerous thing about blåbetong is the radon gas it emits, and you have that in your home all the time if that's the case, not just when you're demolishing. Dangerous to live in? Probably, there are quite a few studies indicating that the risk of lung cancer increases if you're exposed to radon gas for a long time (long time = 15-45 years) AND are a smoker. But use the search function and you'll find a thread where this is discussed in detail with good links to studies as well. Search for my nickname or "daviden," and you should find it.

But it's not more dangerous than that you can stay and do a long-term measurement during the winter, so you'll know for sure how it is.