French Drains

French drains are one of the most versatile and reliable drainage solutions available for Long Island properties, providing a subsurface system that intercepts and redirects groundwater before it reaches your foundation, floods your yard, or damages your hardscaping. Brothers Paving & Masonry has installed French drain systems across Nassau and Suffolk County for years, and we engineer every installation to address the specific soil conditions, water table levels, and drainage challenges that make Long Island properties uniquely vulnerable to water problems.

A French drain is a gravel-filled trench containing a perforated pipe that collects water from the surrounding soil and channels it to a designated discharge point such as a dry well, storm drain, or daylight outlet. The system works by gravity, using the natural tendency of water to flow downhill and seek the path of least resistance. When groundwater encounters the highly permeable gravel bed of a French drain, it enters the trench from all sides, flows through the gravel into the perforated pipe, and is carried away from the problem area. This simple but effective principle has been solving drainage problems for over a century.

On Long Island, French drains are especially valuable because of the island's high water table and varied soil conditions. In South Shore communities where sandy soils dominate, water moves through the ground quickly but can accumulate in low spots and against foundations during heavy rainfall. French drains installed along foundation perimeters or across problem areas intercept this subsurface water and redirect it before it becomes a problem. On the North Shore, where clay-heavy soils retain moisture and drain slowly, French drains provide a critical pathway for water to escape saturated soil zones that would otherwise remain waterlogged for days after a storm.

Our French drain installation begins with a comprehensive drainage assessment. We walk your property during or after rainfall to observe how water moves across and beneath the surface. We identify the sources of excess water, map the areas where it accumulates, and determine the best route for the drain to intercept and redirect the flow. The discharge point is planned carefully to ensure water is moved to an appropriate location without creating new problems for you or your neighbors.

Trench excavation is performed to a depth of eighteen to thirty-six inches depending on the application, with the depth and slope calculated to ensure proper water flow to the discharge point. We maintain a consistent downward pitch of at least one percent throughout the run, and we verify the grade with laser levels to guarantee reliable gravity flow. On Long Island's flat terrain, achieving adequate slope can be challenging, and our experience with local grade conditions allows us to design effective routes even on the flattest properties.

The trench is lined with geotextile filter fabric that prevents soil particles from entering the gravel bed and clogging the system. We then place a bed of clean washed gravel in the bottom of the trench and lay the perforated pipe on top, with the perforations facing downward to collect water from the gravel bed below. Additional gravel is placed around and over the pipe, and the geotextile fabric is folded over the top of the gravel to create a fully wrapped, protected drainage channel. This construction method ensures long-term performance by keeping fine soil particles out of the system while allowing water to flow freely.

We use high-quality perforated PVC or corrugated HDPE pipe depending on the application and site conditions. For foundation drains and applications where maximum flow capacity is needed, we prefer rigid PVC pipe with precisely sized perforations. For yard drainage and applications that require flexibility to navigate around obstacles, corrugated pipe provides a durable and effective solution. All pipe connections are secured with appropriate fittings, and we install cleanout access points at turns and junctions so the system can be flushed and inspected in the future.

Long Island's storm patterns demand that French drains be designed for peak performance, not just average conditions. Nor'easters can deliver several inches of rain in a single event, and tropical storms passing through the region can produce even more intense rainfall. We size our French drain systems to handle these heavy storm events, using larger pipe diameters, wider trenches, and increased gravel volumes when the drainage area or expected water volume warrants it.

Foundation French drains, also called footing drains, are installed along the exterior of your home's foundation to intercept groundwater before it can enter your basement or crawl space. These systems are particularly important on Long Island, where the high water table can create hydrostatic pressure against foundation walls during wet seasons. A properly installed foundation French drain relieves this pressure by capturing water at the footing level and channeling it to a sump pump or exterior discharge point.

Yard French drains address surface and shallow subsurface water that creates soggy lawns, kills grass, and makes outdoor areas unusable after rain. We install these drains across the affected area, often in conjunction with grading corrections, to create a comprehensive solution that moves water both on and below the surface. The result is a drier, healthier lawn and outdoor living spaces you can enjoy even after significant rainfall.

After installation, we backfill the trench above the gravel bed with topsoil and restore the lawn or landscape surface. The French drain is completely hidden from view, with only small cleanout caps visible at grade level. We test the entire system by introducing water at the upstream end and verifying flow at the discharge point before considering the project complete.

Brothers Paving brings the drainage expertise and installation quality that Long Island properties demand. Whether you need a foundation drain to protect your basement, a yard drain to reclaim your lawn, or a comprehensive system that addresses multiple problem areas, we design and build French drains that perform reliably for decades. Call us today for a free drainage assessment and estimate.