No, I did not say that. I simply do not know. But my predecessors do know, and I wanted to be enlightened. I cannot think of any reason to seal the garage made of concrete blocks if it is not basemented.
Because wet masonry has a shorter lifespan and the interior space is less usable. Of course, this should be sealed in the perimeter area (30cm? kA). Bitumen will also be applied under the first row of stones. The floor slab will likewise be coated with bitumen and a welded membrane applied on top.
Moisture will come to the base during rain and snow. Therefore, a slurry is applied on the stone up to about 30 cm above ground level. Above that, plaster is applied. This takes 60 minutes of work and 12,- euros for materials. Why skip that?
Because wet masonry has a shorter lifespan and the interior space is less usable. Of course, it should be sealed in the perimeter area (30cm? no idea). There will also be bitumen under the first row of stones. The base slab will also be coated with bitumen and a torch-on membrane applied on top.
So the base slab can also be made of waterproof concrete, right? I've never seen anything applied on top of it. And the plinth sealing is usually done by the plasterer together with the plinth plaster, isn't it?