The vertical shafts usually range from 20 to 200 meters in depth, although qanats in the province of Khorasan have been recorded with vertical shafts of up to 275 m. The vertical shafts support construction and maintenance of the underground channel as well as air interchange.
Pri gradnji plitvega kanata en delavec navadno koplje vodoravni jašek, eden odnaša izkopano zemljo iz jaška in eden razporeja izkopano zemljo na vrhu.