Question

Why do random slabs stay dry in the rain?

Answer 1

While there are many potential causes of a slab leak, the ... Smell: Wet carpet and flooring, damp and moldy walls: ...

Answer 2

An interesting experiment could be to record how often each slab stays dry after each rain. Maybe a simple pattern emerges. Alternatively, it might be worth checking the dry slabs - maybe they have a different thermal contact to the ground than the others, or are slanted to allow water to run off quicker.