Sealing the garage with a concrete floor?

Just ask him again. Maybe some more opinions will come up here. I can hardly imagine that such a slight slope, especially on rough ground, would have a noticeable effect.

Well, according to the flat roof guideline, a 5% slope should be planned to ensure reliable drainage of flat roofs. That could serve as a reference. However, I wonder why a slope should be planned in the garage at all. What water needs to drain there and, above all, where to? Drains in the garage floor are regularly not permitted.

Second point: Is the bitumen welding membrane on the base plate really so expensive that savings have to be made there?? Is there no horizontal barrier in the masonry either? Or was this now a concrete garage? From a technical point of view, there is nothing against a bitumen welding membrane under the screed.

Which water has to drain away there and especially where to? Drains in garage floors are regularly not allowed.

According to the architect, for example snow, etc. Especially in winter with salt, the slope is supposed to be good, he says.

Second point: Is the bituminous waterproofing membrane on the base slab really so expensive that you have to save on it?? Is there no horizontal barrier in the masonry either? Or was this a concrete garage? From a technical point of view, there is nothing against a bituminous waterproofing membrane under the screed.

First of all:
The garage adjoins the house directly and is, like the house itself, built with aerated concrete.
Under the first row of bricks – that is, on the concrete floor – there is already an Alujet membrane, which extends about 15-20 cm into the room, so that the Katja foil can be connected to it.

Hence my initial question, why isn’t this done?!
I probably still have some membrane left. Probably not enough for everything. But it doesn’t cost the world.

Without the sealing on the floor slab, the sealing under the first row of stones also makes less sense. And when does so much snow come off a car after it has been driven into the garage that the meltwater begins to flow? Or does it snow inside the garage? Even then, the question remains where it should drain. I would seriously think about the architect.

Furthermore, it would be fundamentally important to ventilate the garage, provided it is not to be heated. This way, the car dries better and usually less rust forms.

In addition, it would basically be important to ventilate the garage if it is not supposed to be heated. This way, the car dries better and usually less rust forms.

Are there any experiences with specific techniques here? Commercially available fans with humidity sensors?

In newly built residential areas, 90% of garages can be seen with the doors open 10-20 cm...