This 1990s two-story in Ankeny's Prairie Trail area had a vented crawlspace that was letting Iowa's humid summer air condense on cool surfaces below the home. Mold growth was visible on the floor joists, musty odors were permeating through the first floor, and the existing beam supports were showing signs of settling.
Vented crawlspaces are common in Polk County homes from this era, but they cause more problems than they solve in Iowa's humid climate. Warm, moist air enters through the vents, hits the cooler crawlspace surfaces, and creates the perfect environment for mold, wood rot, and pest infestations.
Our crew started by reinforcing sagging beams with adjustable steel jacks to address the structural settling. We then sealed all vents and installed a 20-mil vapor barrier across the entire floor and up the walls, creating a fully sealed environment.
A commercial-grade dehumidifier maintains optimal humidity levels, and spray foam insulation on the rim joists provides a complete thermal break. This full encapsulation system transformed the crawlspace from a damp, neglected space to a clean, sealed environment. The homeowner noticed an immediate improvement in air quality and a noticeable drop in heating and cooling bills.