ᐅ Brick-and-Mortar Construction vs. Precast Concrete Elements

They are factory-cast and "baked" elements made in one piece. Maximum width, in my opinion, is 0.8 meters (31.5 inches). As mentioned, they are very dimensionally accurate. Elbe-Haus handles the foundation/slab and basement as well as the walls with their own team. Only the other trades are subcontracted to local craftsmen. Their own crews are very familiar with the material and work very precisely. As I said, we have been living in the house since mid-2014, and everything was as promised or specified in the scope of work. Deadlines were also met, even beaten.

Explosiv schrieb:
These are factory-cast and “baked” elements made in one piece. Maximum width, in my opinion, is 0.8m (31.5 inches).
And as I said, very dimensionally accurate.
Elbe-Haus uses their own team for the foundation slab/basement and walls. Only the other trades are subcontracted to local craftsmen. Their own crew is very familiar with the material and works very precisely.
As I said, we have been living in the house since mid-2014, and everything was as promised or specified in the scope of work. Deadlines were also met, even beaten.

Thank you very much for your reply. That sounds good so far. One more question about the prefabricated elements: So these are properly cast parts, like those used, for example, in the construction of warehouses? Basically a foundation slab but as a wall and smaller?
I thought these were Ytong blocks that are essentially dry-stacked and mortared into one large unit in the factory. But I didn’t know everything was basically one single piece.

Then everything must be planned perfectly in advance, right? Because small changes aren’t really possible anymore, since the openings for the pipes have already been dimensioned.

Question about the foundation slab: Is it a proper foundation slab? No strip footing is used? Do you have this “Cosy” foundation slab? I believe it is specially insulated or something like that.

The prefabricated elements are made of aerated concrete. This is quite different from a steel-reinforced concrete slab. However, they are cast in one piece rather than assembled from smaller parts. Several elements placed side by side and glued together form a wall. The exterior walls are connected to the interior walls—also made of aerated concrete or calcium silicate bricks, which are built with traditional masonry blocks—using embedded steel plates. Additionally, a remaining formwork element is placed on top of the wall crown, creating a reinforced concrete ring beam that encircles the entire exterior walls and includes the interior walls as well. There is absolutely no reason to doubt the stability or dimensional accuracy.

As with conventional masonry, changes can still be made afterwards. However, chasing (cutting channels) for wastewater pipes in the exterior walls was not possible in our case because it would have reduced the remaining wall thickness below the insulation required for our 2014 KfW 70 standard. Smaller chasing works for electrical and water lines, on the other hand, were no problem.

And yes, the house design is drafted very precisely and fits perfectly later. The type of masonry doesn’t really matter here because, even when preparing the foundation slab—which must have the exact location of wastewater pipes known and can only be changed later with great effort, if at all—everything has to be planned carefully beforehand. But don’t worry, it fits.

If you have concerns about being locked into your decisions later, let me tell you it’s better to make several changes during the planning stage than trying to change something after construction has started. Late change requests will almost certainly lead to significant additional costs and construction delays. So only approve the factory planning when you are truly sure.

Regarding the foundation slab:
It is a proper slab foundation. However, frost skirts (a kind of continuous strip footing) are arranged around the outer edges to prevent frost from undermining and lifting the slab. The depth of the frost skirt depends on the location of the building site but, in my opinion, is at least 0.8 meters (2.6 feet) and at most 1.2 meters (3.9 feet). Around our finished house, after adding soil, it ended up at about 1.1 meters (3.6 feet); initially, only 0.8 meters (2.6 feet) was dug because it was known in advance that soil would be added later.

And yes, we have this insulated slab foundation, Cosyflor or whatever it’s called, with 6 cm (2.4 inches) of insulation beneath the slab.

Brick by brick gets boring, and we also wondered about prefabricated components when we were searching and came across Elbe-Haus. We found building with prefabricated elements advantageous because it is faster, involves fewer construction issues, and also reduces thermal bridges. Therefore, we looked for companies that use such systems and found Prime Massivhaus GmbH. The process and the agreed price were kept. Apart from two minor delays, we were very satisfied.