Give water under the house one job: leaving.

What to know about drainage matting, and when it's the right call.

Drainage matting works on the same principle as a dimpled drainage board on a foundation wall, laid flat. The molded dimples create a gap between the soil and the sheet, and water always prefers an open channel to saturated ground. Moisture rising from the soil or flowing in during a storm enters the channel network and follows the graded slope of the crawl space floor to a collection basin at the low point. From there, a gravity discharge line carries it outside, away from the foundation. Because the matting covers the floor as a continuous sealed layer, water cannot shortcut around it and pool in a corner, and because the material is high strength plastic, it tolerates crews crawling over it for years of future service visits without losing its function. Matting is deliberately the last layer of the system, sized to the water that remains after exterior interception and perimeter sealing have done their work. It pairs with whole system moisture control where several routes contribute. The full layering logic lives on our crawl space waterproofing service page.

The symptoms that usually lead to drainage matting are on the crawl space repair problem signs page, alongside the other signs that point to the same underlying cause.