Subgrade Moisture Remediation and Thermal Vapor Barrier Encapsulation in Mapleton, IL
Challenge
In Mapleton, IL, a residential crawl space presented critical moisture-management failures, including elevated relative humidity, localized water pooling, and unsealed earth exposure. These factors created an active threat environment for mold growth, wood-boring pest infestations, and structural timber rot. The expert production team at MidAmerica Basement Systems stabilized the environment using a multi-layered encapsulation process, installing a heavy-duty CleanSpace® vapor barrier, high-flow Drainage Matting, and an IceGuard® discharge line freeze-protection system. This project was planned without a sales representative and was managed and executed on-site by Foreman Jacob Quinn and the production crew.
A detailed site assessment revealed severe environmental degradation throughout the crawl space. The primary cause of the moisture was the exposed dirt floor, which allowed ground moisture to continuously evaporate into the crawl space air. This moisture movement raised relative humidity levels close to saturation, creating ideal conditions for mold spores to grow on the wood floor joists. The damp conditions also threatened the home's structural integrity by softening the subfloor and inviting wood-boring pests. Furthermore, poor outdoor drainage allowed rainwater to seep through the foundation walls, causing water to pool in low spots on the crawl space floor.
Solution
To solve these issues, the team designed a system to completely isolate the crawl space from the ground and safely remove any incoming water. The first step of the plan used high-flow drainage matting on the dirt floor to keep water moving underneath the main vapor barrier. Next, the team chose a heavy-duty, multi-layer poly-reinforced vapor barrier to seal the walls and floor, stopping moisture and soil gases from rising. The final piece of the plan was a reliable sump pump system with a freeze-proof discharge line to ensure water could always pump out safely, even during freezing Illinois winters.
Foreman Jacob Quinn and the crew executed this plan using a precise, non-destructive installation sequence. The team cleared all debris and sharp rocks from the crawl space floor before laying down the dimpled CleanSpace® Drainage Matting. This matting creates a dedicated space beneath the barrier, allowing water to flow freely toward the sump pump basin without pushing up against the liner. Next, the crew installed the CleanSpace® vapor barrier, a 20-mil, poly-reinforced polyethylene liner. The team ran the liner up the foundation walls and secured it with heavy-duty plastic anchors, sealing all seams with waterproof tape to create a continuous, air-tight barrier.
To handle outside weather risks, the crew installed the IceGuard® system on the sump pump's outdoor discharge line. This patented fitting is built directly into the pipe just outside the foundation wall. If the main underground pipe freezes or gets blocked by snow, the slotted openings in the IceGuard® fitting give water an alternative exit route, letting it drain safely onto the lawn. This prevents water from backing up and flooding the crawl space.
The completed project successfully resolved the home's moisture and structural risks. The encapsulation system completely isolated the home from the damp ground, immediately dropping relative humidity levels and stopping mold growth. The drainage matting and sump pump work together to keep water moving safely away, protecting the foundation. With the IceGuard® system protecting against freezing temperatures, the home now has a dry, stable, and mold-free crawl space that is protected year-round.
