Fact is, dampproofing material wasn't created to protect basements – or even repel water, for that matter. It's actually a type of unmodified asphalt originally created to prepare road surfaces for other materials.
In typical installations, dampproofing is applied in a layer that's at most 10 mils thick when cured. The material degrades quickly underground, becomes brittle and shatters at low temperatures.
Dampproofing won't span foundation settling cracks. As the foundation develops new cracks over time, dampproofing cracks right along with it. These cracks can serve as water channels rather than providing a shield against water. And, unlike waterproofing, dampproofing won't stop water under hydrostatic pressure, which occurs naturally underground.