Problem: Persistent Water Intrusion in Retaining Walls and Inadequate Drainage
A client in West Sayville, NY reached out to Zavza Seal with concerns about persistent water intrusion around the retaining walls of their basement stairwell. The issue stemmed from several contributing factors:
- Poor drainage from the existing sump pump system
- Water seeping through both sides of the cinder block walls
- Compromised stucco and visible water stains
- Heavy hydrostatic pressure buildup due to lack of relief drainage
The existing system was not effectively channeling water away from the foundation. Over time, the basement walls began showing early signs of water damage, and there was growing concern about future foundation cracks or structural bowing.
The homeowner had already removed part of the exterior stucco in an effort to locate the moisture source but was unable to stop the leaks. Recognizing the potential long-term damage and the importance of timely intervention, they contacted our Zavza Seal waterproofing team for a comprehensive solution.
Solution: Full-Service Retaining Wall Waterproofing and Drainage Upgrade
After a thorough site evaluation, our project manager and estimator developed a multi-step strategy to permanently address the water intrusion and upgrade the sump drainage line. Here’s how Zavza Seal resolved the issue:
1. Extending the Ejector Line
To reduce pressure around the sump pit and ensure proper water redirection:
- We extended the ejector line horizontally through the retaining wall.
- The pipe was angled to rise and flash just below exterior grade level.
- A check valve was installed using PVC adapters and stainless steel clamps to prevent water backflow into the sump pit.
2. Street Drainage Integration
To divert water efficiently away from the property:
- We angled the new line toward the street and drilled through the curb using a diamond bit sized precisely to the pipe diameter.
- A 12-inch-deep trench was excavated from the home to the street curb.
- We installed a solid PVC pipe to channel sump discharge directly to the curb, preventing water from pooling near the home.
3. Waterproofing Cinder Block Basement Walls
Water penetration through the basement stair retaining walls was another major concern. Our waterproofing team executed the following steps:
- Excavated along both cinder block walls down to the footings (approx. 26 linear feet).
- Provided shoring for safety and structural support.
- Cleaned wall surfaces with steel brushes and repaired cracks using 4.5 oz reinforced fiber mesh layered between waterproofing cement.
- Applied liquid rubber waterproofing across the entire wall and footing.
4. Membrane Installation
To ensure long-term resistance to hydrostatic pressure:
- Installed a Delta-brand heavy-duty dimpled waterproofing membrane, which included recycled HDPE on the interior layer and virgin HDPE on the exterior.
- The dimpled pattern allows incidental water to flow into a new pressure relief drain at the footing.
5. Pressure Relief and Sump Pump Connection
To relieve lateral pressure on the cinder block walls:
- Installed a 4-inch perforated PVC pressure relief pipe at the base of the walls.
- Used filter fabric and gravel to prevent clogging.
- Connected the pressure relief system on both sides of the wall to the existing sump pump basin, which had been correctly installed by the homeowner.
6. Stucco Restoration
- Where the client had removed the exterior stucco, our crew applied wire mesh and a stucco parge coat, blending the finish as closely as possible to the surrounding area.
7. Final Touches
- Backfilled the trench and foundation walls to original grade level.
- Graded the soil away from the structure.
- Used a plate compactor to tamp the soil and ensure settlement would not occur.
Results: Waterproof, Pressure-Free Retaining Walls and a Functional Drainage System
The client in West Sayville now has:
- A dry, structurally sound basement stairwell
- A sump system that efficiently channels water to the street
- Foundation walls sealed with advanced liquid rubber and dimpled membranes
- Long-term protection against hydrostatic pressure and foundation shifting
This project showcases Zavza Seal’s expertise in basement waterproofing and sump pump drainage solutions for homeowners in West Sayville and the wider Long Island area.
Why This Matters: The Cost of Delaying Waterproofing Repairs
Many homeowners underestimate the risks of letting water intrusion persist. In this case, early intervention saved the retaining walls from significant structural stress and cracking. If ignored, the issues could have led to:
- Foundation bowing
- Mold growth inside basement walls
- Stucco damage and exterior erosion
- Costly structural repairs
Need Waterproofing in West Sayville or Nearby?
If you’re noticing water pooling around your foundation, basement leaks, or signs of moisture damage, don’t wait. Zavza Seal specializes in foundation waterproofing, sump drainage systems, and retaining wall repair throughout Long Island, Queens, Brooklyn, and the Bronx.
Contact us today to schedule a site inspection and protect your property before small issues become major problems.