French Drains Installation in NYC, Brooklyn, Westchester, & Rye

A wet basement and the associated groundwater accumulation can affect the structural integrity of a home, dramatically reduce the home’s value, and cause a number of health-related problems.

For cases involving hydrostatic pressure (water pressure from things such as underground springs, rivers, ground water, etc.) and a fluctuating high water table (a build-up of ground water that lies close to the surface of the earth) an interior French drain is needed. The interior French drain, also known as subfloor pressure relief system, was designed, invented by the ancient Romans but popularized by Henry French, a Concord, Massachusetts judge and farmer, who wrote about them in his 1859 book, Farm Drainage.  For more information, call 516-614-5652 or click here to make an appointment with one of our basement waterproofing experts at your property.

Three Common Uses of French Drains

French Drains From Superior Restoration and Remodeling
  • Shallow curtain drains to divert surface water
  • French drains built into a retaining wall to eliminate pressure build-up on the wall
  • Interior French drain “ sub floor drainage” to stop water where it enters the home

What is a French Drain?

A shallow curtain drain can be used to eliminate problem areas on your property where water build-up can occur, such as a low spot on the lawn or a continually washed out landscaped bed. It can also be used to divert water around your house. This fairly shallow drain extends horizontally across your property, uphill of the area you want to dry out and redirects the water to either side.

A curtain drain usually consists of a trench, often lined with landscaping textiles that prevent clogging from dirt or roots and one or two perforated pipes surrounded by gravel, (depending upon sizing and redundancy requirements and always placed perforated side down), and covered with sand for further filtration of sediment.

In addition to their primary function of directing water away from your home, exterior French drains are also environmentally proactive as they can lead to a dry well, a structure that returns excess water to the supply of groundwater, or to a rain garden, an environmentally friendly invention that uses wetland plants to absorb excess water and return it to the atmosphere through transpiration.

Any retaining wall that is built into a hillside should incorporate a French drain so that the wall footings don’t give out from the water pressure that can easily build up behind the wall on the downslope.

Interior French Drains

Hydrostatic pressure is caused by underground springs, rivers, and/or a fluctuating high water table. Signs of hydrostatic pressure include water that seeps in at the cove (where the wall meets the floor) or up through the slab floor. A solution to relieve hydrostatic pressure must entail:

  • Relieving the water pressure under the floor and around the foundation perimeter
  • Diverting the water to a point where it can be pumped out or otherwise removed from the basement.

A hydrostatic pressure relief system requires no outside digging or destruction of property. It involves jack hammering a trench in the floor around the perimeter of the basement, next to the foundation walls. The trench must be excavated next to the footings and a perforated pipe is laid all the way around. The system must be adequately sized so that it can carry off all the water to a collection tank installed into the floor (sump pit ) and a sump pump carries it out to the yard or a storm drain. After the pipes are installed, clean outs are installed for non clogging of the pipes; the trench must be filled with gravel, bleeders installed in the block walls when doing block foundation work, and the trench re-covered with concrete for completion of install.If the hydrostatic pressure relief system is not properly designed, it will clog and backup, or worse yet, undermine the integrity of your foundation.”. This approach of using the long term solution of relieving the water “pressure” to control basement water problems by the means of installing the pressure relief system will end most basement water problems.