[flaviu2]

ah, I see.

> Emissions from a nearby CIPP job got indoors through cracks in the building’s foundation and irritated workers to the point that they evacuated

This is fascinating. I've always thought of dirt and concrete as being basically impenetrable to things like this, but apparently they're not!

[ryanobjc]

Concrete is porus to water. If water can seep thru, when it’s not cracked, air can as well.

[blawson]

Water molecules are smaller than air though, so a surface can be airtight and not be watertight.