Drainage Tile / French Drain / Under Drain:

Drainage tile, sometimes referred to as French Drains or Under Drains in the industry, is 4” – 6” corrugated flexible drainage pipe which is installed underground in a trench back filled with clean 3/4” drainage stone. The premise behind the design is to wick water from an underground water source and redirect it into a catch basin, drainage area or other suitable area.

Simply, the objective is to prevent water from reaching the surface of your parking lot, sidewalk or other area where ground to surface water caused by hydraulic pressure.

A constant stream of water to the surface from below ground can cause all types of liability issues such as: ice in the winter, moss growth creating an equally slippery surface as ice, clients / customers having to navigate around the wet areas to keep their shoes dry etc.

We have completed many of these exotic projects where property managers felt they would have to deal with water issues for the life of the property, only to have us provide a comprehensive solution and solving their underground water issue in its entirety.

What Causes Underground Water Issues In Parking Lots?

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How Much Does French Drain Installation Cost in New Jersey?

$45.00 - $60.00 per lineal foot

The cost of drainage tile / french drain / under drain is in New Jersey is dictated by:

• Amount of lineal footage
• Depth to the underground water source
• Disposal cost for excavated soils
• What type of structure is the pipe being plumbed into to wick the water away from the underground spring (ie: catch basin, existing buried pipe, storm water retention pond etc)
• Restoration work (ie: patching back asphalt, concrete, curbing, sidewalk, landscape islands etc)

How Is Drainage Tile Installed?

Watch the video below for a full explanation of what drainage tile is, how it works and what type of groundwater issues it will correct.

The proposed excavation area is first marked with white paint and a Utility Locating Company is contacted to mark the area for underground utilities

The asphalt is removed and the sub grade is exposed.  As you can see from the picture above the ground water is visible at a depth of aprox. 12"

A trench is excavated to the depth of where dry soil is encountered

The drainage tile is installed into the trench with a soil separation fabric to prevent dirt and other fines from contaminating the clean 3/4" stone and clogging the holes in the pipe.

Clean 3/4" stone is back filled around the pipe to draw water out of the soil and into the tile bed.  The pipe is then plumbed into either a catch basin, existing buried drainage pipe or a storm water retention pond.  

The area is then prepared for new asphalt to be paved over the trench and repair area