Sub-foundation areas like crawlspaces and basements are often the source of hidden moisture and mold issues. A sealed, ventilated, and odor-free crawlspace is ideal, but many homes fall short in this area. Musty smells, trench drains, sump pumps, and visible mold are all red flags. Even properly maintained basements can pose risks if they are below-grade and have a history of water intrusion.

Concrete slabs should sit above grade with the surrounding soil sloped away to promote runoff. Be cautious with homes that have exposed slab edges or signs of water pooling along exterior walls. If any foundational area shows signs of deterioration or chronic dampness, it warrants a deeper inspection.