In residential and commercial construction, you probably don’t think much about what lies beneath the surface. However, every type of building has some sort of foundation drainage that takes water away from the building to prevent foundation cracks, leaks, and hydrostatic pressure. The importance of such drainage cannot be understated; it’s just as important as any other facet of the building. So if you didn’t know about foundation drainage, check out some of the most common types, how they work, and why they’re integral to any structure.
As the name implies, a footing drain sits adjacent to the footing of the foundation of the building. When it rains outside, the water runs through the soil or the side of the foundation into the footing drain, which is carried away from the building. Some footing drains send the water to a storm drain, a sump pump, or back to the surface.
Although the name is misleading, the French drain wasn’t invented in Paris. It was actually the creation of Henry French, a resident of Massachusetts in the early 1800s. Surrounding the perimeter of a building or structure, a French drain uses a perforated pipe that sits below the foundation. It also goes around the entire perimeter of the structure, hence the alternative name of perimeter drains.
The holes in the pipe allow water to run off from the foundation and into the pipe, which is then whisked away from the building and into a sewer. The pipes are also angled away from the structure to avoid any inadvertent hydrostatic pressure.
Sump pits that are accompanied by a sump pump are one of the oldest drainage solutions in modern construction. The sump pit is merely a hole cut into the floor of the foundation which features a perforated bin, typically made out of plastic.
The sump pit gets filled with water by either holes in the side of the plastic or through the natural migration of the water. Once the water hits a certain level within the sump pit, the sump pump springs into action. The sump pump then takes any extraneous water away from the building and into a sewer or storm drain, effectively limiting the chance of a flood.
As the name implies, a grading drain uses a piece of concrete or similar materials to propel water away from the foundation. The grading drain isn’t so much of a drain as it is a simple slope that allows the water to drain. The steepness of the grading drain varies, but it’s usually at least 60 degrees to ensure that no water or pressure builds up along the foundation.
EPS Engineering in the Bay Area has been focused on underground construction, plumbing, pipes and drains for multiple decades. Contact us to discuss your next project and we’ll be happy to go over all the options available to you with a detailed proposal.