What is interior drain tile?

Interior drain tile consists of perforated plastic or corrugated pipe positioned along the interior footing of a basement foundation, running beneath the concrete floor slab. As groundwater and water vapor accumulate under the slab, the perforations allow water to enter the pipe, which then channels it to a sump pit or pump for removal from the basement.

The system works by intercepting water before it can infiltrate the basement or build hydrostatic pressure against the foundation. This approach is often used when exterior drainage (such as exterior drain tile or French drains around the outside of the foundation) is not practical or has become compromised. It is also common in finished basements or where the exterior perimeter cannot be excavated.

In Rock County's climate and soil conditions, where seasonal groundwater fluctuations and saturated clay soils are common, interior drain tile helps prevent water seepage, efflorescence, and mold growth. The sump pit is typically fitted with a pump that cycles water away from the house, keeping the basement dry. Installation involves cutting the concrete slab, laying the perforated pipe, and then resealing the floor. Proper slope and grading of the pipe are critical to ensure water flows toward the sump pit reliably. For homeowners dealing with persistent dampness or minor seepage, interior drain tile offers a practical retrofit solution when working with basement waterproofing providers.