Shrinkage cracks - allowable width

Hello everyone,

we are about to sign our contract. It contains a passage which I will quote:

"Excluded from the warranty are ground settlements in the area of the work rooms, insofar as they concern backfilled outdoor areas, as well as shrinkage cracks, especially in the attic, which have no significance or consequences for proper execution. Shrinkage cracks are caused by different expansion behaviors of various materials. Here, the contractor recommends a finishing coat in the course of the painting work."

I understand that cracking can occur in house construction. This is apparently normal. We are building with waterproof concrete in quality C25/30 (according to the construction specifications).

During the contract review, I received a note from the expert of the Houseowners Protection Association that shrinkage cracks up to 0.2 mm are normal. However, he could not provide evidence for this. Therefore, I asked my construction company to change the text to "as well as shrinkage cracks up to 0.2 mm, especially ...". The construction company in turn contacted a renowned TÜV expert who told them that there is no fixed size/width for shrinkage cracks. Therefore, the construction company does not want to change this passage.

I am a layperson and have two different expert opinions here. Can any of the professionals present here tell me if there is a standard/DIN/regulation regarding the maximum permissible crack formation and where I can find it?

I have a pretty good relationship with the construction company and only want to strain it if there are actually concrete guidelines on this. Otherwise, I rely on the information from the construction company and their good reputation.

Hello,

We are constructing with waterproof concrete in quality C25/30 (according to the construction service description).

During the contract review, I received a note from the expert of the Bauherrenschutzbund that shrinkage cracks up to 0.2 mm are normal. However, he could not provide evidence for this.

This confirms my previous impression of the ladies & gentlemen; your description does not make it any better ...

Accordingly, I asked my construction company to change the text to "as well as shrinkage cracks up to 0.2 mm in particular ...". The construction company, in turn, contacted a renowned TÜV expert who told them that there is no fixed size/width for shrinkage cracks. Accordingly, the construction company does not want to change this passage.

Then this TÜV guy should go back to school. There are limit values for crack widths; you will find the table attached**.

There are standards for everything; we live in Germany

**Source: Prof. Dr.-Ing. Baumgart; Hochschule Darmstadt


Rhenish regards

There are standards for everything; we live in Germany

**Source: Prof. Dr.-Ing. Baumgart; Hochschule Darmstadt

Hello Bauexperte,

thank you for the graphic.
It comes from the dissertation/thesis of Prof. Baumgart. I also stumbled upon it today while googling and downloaded it.
Unfortunately, I don’t understand 75% of it (and I consider myself reasonably educated – but I have no clue about construction).

I also couldn't figure out which building regulations he refers to. Can you perhaps help me here? Or do all experts/surveyors refer to this work?

At the end of the dissertation are, imho, the references to the 3 (I think there are 3) DIN. If not, you can find them via Aunt Gurgle at Beton.org with the search aid "Schwundrisse & Beton"

Rhenish greetings

Construction expert, on the road

Hello,

I am currently in the office.

I also couldn't figure out which building regulations he is referring to. Can you maybe help me here?

He is referring to DIN EN 1992-1-1 and DIN EN 1992-1-1/NA, 2011 as well as the standard group DIN EN 1504

Rhenish greetings

Thank you very much for the response. It helps me a lot.