Alternatives to standard asphalt around roots

[Evo]

I'm drawing a fuzzy on how moisture condenses (from the air?) through the impermeable asphalt to the soil underneath? Can you set me right? Or am I misunderstanding?

The soil moisture condenses on the underside of the impervious layer. Soil temp is fairly constant add a layer of concrete that warms up which creates a impervious temperature differential..
read up on attic frost/snow, essentially the same concept

Frost in attics: why it's there and how to fix it

If you have a problem with frost in your attic, you're not alone. The last few weeks of very cold weather has led to a lot of frost-covered attics.

structuretech.com

 

[Bart_]

I can get condensation, but the moisture has to get transported into the soil from somewhere in the first place. Does it just soak in sideways from nearby pervious-surfaced soil, or are we talking high ground water level (from below). ? Remember the roots are constantly sucking the soil dry (I presume).

Is there some amount of normal topsoil dries from the surface downwards so a sealed top layer prevents evaporation?

Not sure if soil has the same moisture holding capability vs temperature property as air. (?) Ie like relative humidity. I think that's the primary driver of condensation effects from air.