Moisture around a slab foundation can lead to sinking, uplifting, and foundation cracks. There are a few ways to improve drainage around your foundation. Most homes benefit from using one or more of these methods.
1. French Drain
French drains are typically installed along the downslope grade, often at a perpendicular angle to the foundation wall. They are most often used in areas near the foundation where water tends to pool. A perforated drain pipe, sometimes called a drain tile, is installed inside a gravel-filled trench. Water seeps into the pipe and is routed away from the foundation.
2. Footing System
A footing drain system is one of the easiest options to install around an existing foundation when you need a complete perimeter drainage system. A shallow trench is dug around the foundation and a perforated drain pipe is installed so that the top of the pipe is level with the foundation footing. A thin layer of gravel covers the top of the pipe so that moisture can still percolate through. The idea is that moisture drains into the pipe instead of flowing between the foundation seam.
3. Grading Drainage
If you have some major water flow issues that cause water in the landscape to flow toward your home, then reworking your property's grade may be the best solution. This is a major endeavor that requires digging up the yard and adjusting the grade so that the yard slopes down and away from your foundation, preferably to a storm drain, culvert, or similar.
4. Integrated Systems
Integrated systems for slab foundations are best installed when the house is first being built, so they are only a solution for preventing future drainage issue possibilities. Gravel-filled drainage trenches with integrated drain pipes are installed through the foundation so that any soil water that presses against the foundation can be routed through the pipe without harming the foundation. These systems are especially useful for homes that sit partially up a slope.
5. Gutter Routing
The roof gutter system may not immediately seem like a part of a foundation drainage design, but it is a contributing factor for foundation moisture issues so it must be considered. Instead of rainwater flowing off the roof and collecting near the foundation, it is routed through a gutter system and into a downspout. Ideally, the downspout will be plumbed into an underground drainage system that routes water well away from the foundation.
Contact a foundation drain design team to learn more about suitable options for your home.