Build a basement out of aerated concrete?

Hello everyone,

we are planning to build a house with a basement, our plot is ideal for it. Now we have chosen a solid construction company. While reading the building and service description, I noticed that the basement is supposed to be built from aerated concrete PPW with a wall thickness of 36.5 cm. Since my whole family has built houses, I sought advice and everyone unanimously said that they would not build a basement from aerated concrete. Now my question is: Does anyone have experience with this and what is the opinion on the topic of aerated concrete in basements?

Hello,

Since my whole family has built houses, I sought their advice and they all unanimously said that they would not build a basement out of aerated concrete..

What reasoning did your family provide for this?

Kind regards

My family said that aerated concrete absorbs water quickly and in large amounts. It was said that if the exterior walls are sealed against moisture and there is only a tiny leak, the aerated concrete will absorb water quickly and it does not really dry out again. Another construction company that builds with bricks told me that it could be a disadvantage to build the house with aerated concrete, especially if there is a lot of rain during the construction period, the Ytong would soak up a lot of water.

Hello,

... Another house construction company that builds with bricks told me that it could be disadvantageous to build the house with aerated concrete, especially if there is a lot of rain during the construction period, as the Ytong would soak up a lot of water...

Capillarity on the one hand determines how quickly a component absorbs water when it comes into direct contact with moisture (rain, splash water in the kitchen and bathroom, ground moisture, condensation water); on the other hand, it determines the drying speed of new or renovated components or walls in which water vapor transported by diffusion has condensed into water. A useful measure for the capillarity of building materials is the water absorption coefficient (w); the water absorption coefficient indicates how much water the material absorbs within a certain time. It indicates how much water, measured in kilograms, penetrates into the completely dry material through one square meter of wetted surface area within a certain time – for example, in one second or one hour. For many building materials with a low water absorption coefficient, i.e., only slightly developed capillarity, a particularly high "water uptake" is characteristic**.

The capillarity of sand-lime bricks, pumice or aerated concrete (porous concrete) is rather weakly developed. Therefore, it takes much longer than with bricks, for example, until they have absorbed the same amount of water. Or heretically: aerated concrete is not sold as Seramis®.

**Source: Eichler, Friedrich; Arndt, Horst; Technical Heat and Moisture Protection in Building 1989; Bauverlag Kur, Friedrich; Wohngifte, Handbook for Healthy Building and Furnishing, 3rd edition, Eichborn Publishing, 1993, p. 545

All building materials have advantages and disadvantages

Kind regards

So I would first wait for/have a soil survey carried out and then, based on this survey, make a decision on how to build the basement – regardless of all those who have so much supposed knowledge about house building because they have either built a house themselves or at least know someone who has built a house before.

That is likely to be much more informative, and if you then post this result here, you can be given reasonable advice. Sorry that I don’t have a crystal ball or can’t read in it.