Fully Encapsulated Waterproofed Crawl Space

The absolute strongest and longest-lasting foundation available today is the pier and beam style, with the added modification of full encapsulation and perimeter french drain. With these key steps, there is nearly zero chance of shifting, and basically no moisture problems whatsoever. The cost difference is big, but the end result is unparalleled.

Full encapsulation provides a moisture barrier to the crawlspace by installing a layer of plastic sheeting along the ground floor, and then sealing the edges at the beam and piers. This prevents moisture from rising up toward the house floor, which prevents the musty smell that otherwise and inevitably develops over time. However, this part is not enough, as a plastic barrier without a release point for the moisture below this, will build up and create a musty and moldy problem of its own. This is where the perimeter french drain comes in.

With this newer class of foundation, there are no traditional vents to provide for fresh air in and out of the crawl space. Vents are good for many reasons, but not useful if the crawl space is fully encapsulated. Instead, what is required for ventilation is a gravel trench drain (french drain) to create that air gap which allows water to escape from around the house. Any ground water that seeps toward the foundation from the surrounding property and any ground water that comes up from the center is provided an easy outlet via the age-old french drain, due to air space between the gravel aggregate. Water always goes to the lowest and most accessible point, and the french drain provides just that, as it is installed lower than the beam.

While not required by design, going the extra mile is to waterproof the outside of the beam, via a liquid-applied membrane and dimple board system. These layers of defense will prevent any moisture from working its way into the crawlspace, either from below (with encapsulation) or from the sides (with a waterproofing system.) 

We recently had the opportunity to be a part of a new home build for one just like this in north Dallas, and wanted to present photos and a video detailing our process. If you desire the highest in quality and can afford the difference, you’ll appreciate the comfort provided by a completely dry crawl spaces and the assurance of minimal foundation issues for years to come. Check out these photos and enjoy the video, and if you’re considering the best of the best for your new home, call Dallas Drainage Pros!