Drainage Systems & Retaining Walls

SURFACE DRAINS

Surface drains are the most common and easily recognizable drains we install. They are also the most commonly confused drains! Surface drains get their name, as they are installed just below ground level and the main purpose is to collect surface level water.

This drainage system is often utilized with negative drainage - water sloping toward a foundation - in which large amounts of rain water could travel across the surface of the soil. A surface drain may also be necessary around the perimeter of a structure without a guttering system, as large amounts of water come off the roof during heavy rains.

Easily recognizable by the catch basins installed at ground level, surface drains have a wide array of grates. This allows water to pass with the function of catching other debris before entering. These catch basins are normally spaced every 8-12 feet, depending on expected water flow and are connected by 4” solid PVC pipe at a 1% slope. Water is ejected from the catch basin by installing exit pipe - Perma-Pier uses smooth PVC - at the low end of the drain. It is discharged at a safe distance to protect the foundation.

At Perma-Pier Foundation Repair of Texas we use low-profile catch basins, which eliminate the possibility of breeding mosquitos as opposed to standard boxes.

CHANNEL DRAINS

The purpose of channel drains is essentially the same as surface drains. The major difference is channel drains are designed to collect water run-off from hardscapes, or concrete surfaces.

Channel drains are often found in driveways and patios which have a tendency to collect water. Occasionally we see driveways with a steep decline into a garage or pool that is slightly higher than the patio next to it. Both of these situations are less than ideal as they could lead to water entering your structure uninvited!

Channel drains are installed by saw-cutting a straight “channel” through the hard surface and placing a precast plastic form in the freshly cut channel. Once this is properly secured, a grate cover is placed on top and the drain is now safe to step on or even drive over. Similarly to the surface drain, smooth PVC is used by our Perma-Pier specialists as exit pipe to eject the water a safe distance away from the drain and structure.

FRENCH DRAINS

French drains differ from surface and channel drains, as they are intended to collect subsurface water rather than surface water. When water is absorbed into the soil to the point the soil is unable to absorb any additional moisture, the water does not just continue straight down; it also migrates whichever direction is downhill. This subsurface water will move right past a surface drain so a French drain is needed.

French drains are constructed by digging a trench across the path of any possible subsurface water travel. Once the trench is dug, it is lined with a semi-permeable cloth and a perforated PVC pipe is placed in the bottom. The trench is then filled with 2” river rock and covered with soil once more. If a French drain is properly installed, you won’t even know it’s there!

When migrating water hits the cloth-lined French drain, it passes through and quickly falls through the rocks until it reaches the perforated PVC pipe. The water then enters through holes along the side of the pipe and is carried away from the foundation. Once the water reaches the end of the drain, the perforated PVC is replaced with smooth PVC and discharged at a safe distance.

RETAINING WALLS

Retaining walls are often used in areas where run-off water is causing soil erosion but may also be used to simply add aesthetic appeal to a home’s existing landscape. Perma-Pier Foundation Repair of Texas believes in providing our customers with reliable, lasting products. Talk with our professional team about interlocking stone walls, as they outlast other retaining wall structures.

It is especially important to use an experienced contractor or foundation repair company when considering replacing or installing any retaining wall. The soil behind a retaining wall produces tremendous amounts of pressure, especially when wet. This causes a signifanct force of pushing against the back side of the system. If improperly installed, the entire retaining wall could fail and collapse causing you even more worry, time, and money.