Sometimes homeowners are made aware of the possibility that mold and fungus may be in their crawlspace when mold starts growing on their interior walls or furnace vents. Other times they smell a musty or earthy smell when they enter their home. Most of the time they discover the mold when either they or a contractor enters the crawlspace to perform other tasks. ie: HVAC, termite inspections, plumbers, home inspector etc. Mold can often contribute to allergy and asthma problems. Home owners will overlook the crawlspace as a potential source for the mold.