The Problem:

Zavza Seal completed a professional French drain installation in Holbrook, NY to stop recurring basement water intrusion and foundation moisture issues. A homeowner in Holbrook, NY contacted the companyl after experiencing repeated water intrusion through the back foundation wall during heavy rainstorms. Water was pooling in the backyard and flowing directly toward the house instead of away from it.

The yard had not been graded properly, and the existing downspouts were discharging water too close to the foundation. During storms, the volume of water overwhelmed the soil, forcing moisture through the foundation wall and into the basement.

To make the situation more challenging, an underground electric pipe ran through the area where drainage was needed. Any solution had to work around this utility without disturbing or damaging it.

The homeowner needed a permanent exterior drainage solution that would redirect water safely away from the house and protect the foundation long term.

The Solution:

Zavza Seal designed a comprehensive exterior drainage system that addressed surface water, downspout discharge, and subsurface water pressure along the foundation wall.

Downspout Drainage System

We began by excavating trenches to reroute the downspouts underground. Solid PVC drainage pipe was placed inside the trench, and each downspout was extended below grade using proper fittings and adapters.

At the end of the trench, we excavated deep and wide enough to install a drywell set on a bed of gravel. A pop up emitter was installed to safely release excess water to daylight during heavy rainfall events. This ensured that roof water was moved far away from the foundation instead of soaking into the soil near the home.

Working Around the Underground Electric Pipe

To avoid removing or disturbing the underground electric pipe, Zavza Seal excavated a deeper trench. This allowed the new drainage pipe to be installed safely beneath the electric line. While this required more labor and deeper excavation than originally anticipated, it prevented unnecessary electrical disruption and ensured a clean, code-conscious installation.

Exterior French Drain Installation

To stop water intrusion at the source, we installed an exterior French drain system around the back and west sides of the home.

The trench began at the northwest corner of the house and continued along the back wall for approximately 50 linear feet. From the southwest corner, the trench extended toward the south fence for about 20 feet, then turned west toward the west fence for an additional 70 feet.

All stones removed during excavation were set aside for reuse. Mulch was spread along the west fence, and excess soil was removed from the property.

Along the foundation wall section, the wall was steel brushed below grade and thoroughly waterproofed using liquid rubber. A high performance Blueskin WP200 self adhered waterproofing membrane was installed over the liquid rubber for added protection.

A gravel bed was placed along the foundation wall, followed by a 4 inch perforated drain pipe wrapped in a soil separator fabric. Additional stones were installed over the pipe to promote proper drainage and longevity.

To avoid damaging the existing paver patio, our team used a method similar to hydro jetting to run plumbing beneath the patio without removing it. This approach took more time but preserved the homeowner’s outdoor space.

For the remaining trench sections, a solid 4 inch drain line was connected to the perforated pipe and extended all the way to the west fence, where water could safely discharge to daylight. The trench was then carefully backfilled to complete the project.

The Result:

The backyard drainage issue was fully resolved. Water is now redirected away from the foundation, downspouts no longer discharge near the home, and hydrostatic pressure against the foundation wall has been significantly reduced.

Since the installation, the homeowner has not experienced further water intrusion during heavy rains. The foundation is protected, the yard drains properly, and the home is better prepared for future storms.

Why This Matters for Holbrook Homeowners?

Homes in Holbrook and across Long Island are exposed to heavy rainfall and changing soil conditions. Poor grading and short downspout discharge are common causes of basement water problems. Exterior drainage systems like French drains and underground downspouts are some of the most effective ways to protect a foundation before water becomes an interior issue.

This project shows how Zavza Seal creates custom drainage solutions that work with existing utilities and landscaping while delivering long lasting results.