Water intrusion problems around basement staircases can quickly turn into serious foundation and mold issues if they are not properly diagnosed and repaired. That was the situation our team at Zavza Seal faced during this waterproofing and drainage project in Syosset, New York.

The homeowner was dealing with multiple sources of water penetration around the basement staircase area, foundation walls, door frame, and exterior drainage system. There were also signs of mold contamination caused by long-term moisture exposure.

Our goal was to identify the exact causes of the water intrusion, repair the damaged areas, improve drainage, and fully waterproof the affected sections of the property.

The Problem:

The basement staircase on the south side of the home had several active water intrusion points.

During our inspection, we identified three major problem areas:

• Water penetration through the side foundation wall
• Water leaks around the basement door frame
• Drainage failure at the bottom landing near the sump pump area

The homeowner also had standing water outside near the walkway, staircase, fence, and pool area. In addition, moisture intrusion behind basement plywood had caused visible mold contamination along one corner of the foundation wall.

Without proper repairs, these conditions could continue damaging the foundation, basement finishes, and indoor air quality.

Exploratory Waterproofing Inspection

Before beginning the full repair process, our team conducted detailed exploratory testing to determine the exact causes of the water intrusion.

This included:

• Water testing around the foundation wall
• Drainage testing near the staircase landing
• Inspection of the sump pump and underground drain lines
• Evaluation of leaks around the basement door frame

This step allowed us to create a targeted waterproofing and drainage solution instead of relying on guesswork.

Staircase Drainage System Repair

One of the biggest issues was poor drainage at the bottom of the basement staircase.

The original drainage system was failing, causing water to collect around the stairs and increase pressure against the foundation walls.

Our Solution

• Demolished and removed the existing concrete slab
• Excavated and removed the old dry well and storm channel
• Installed a new 18-inch stormwater pit basin with galvanized steel grate
• Connected the new system directly to the existing interior sump pump basin
• Installed a new 4-inch steel wire reinforced 4,000 PSI concrete slab
• Properly pitched the slab toward the center drain for improved water flow

This new system eliminated standing water buildup and improved drainage performance around the basement staircase.

Foundation Crack Repair

A structural crack near the staircase and sump pump area was allowing water to enter the basement foundation wall.

To repair the crack, our team:

• Ground and drilled the crack every 6 inches vertically
• Injected epoxy resin to stabilize and waterproof the crack
• Covered the repaired area with reinforced waterproofing cement and mesh

This repair restored structural stability while sealing the crack against future water penetration.

Door Frame Leak Repair

We discovered that water entering around the basement door frame was actually coming from the joint between the house foundation and staircase foundation.

Our Repair Process

• Removed the wood frame to access the joint
• Drilled injection access points along the entire joint
• Installed corner injection ports
• Injected epoxy and urethane waterproofing materials
• Applied two layers of 7,000 PSI Basecrete waterproofing cement with reinforced fiberglass mesh between the layers
• Reinstalled the wood frame and sealed all edges with caulking and sealants

This process permanently sealed the leaking joint and protected the area from future moisture intrusion.

Exterior Foundation Waterproofing

Along the exterior staircase foundation wall, water pressure and moisture exposure had damaged the wall surface.

Our team:

• Excavated approximately 2 feet down along the foundation wall
• Cleaned and prepared the exposed surface
• Applied a heavy waterproof liquid rubber membrane
• Removed old coatings and exposed the bare concrete
• Installed reinforced fibermesh between two layers of waterproofing cement

This helped create a durable waterproof barrier along the exterior wall.

Exterior Drainage Improvements

The property also had significant water pooling near the mulch beds, walkway, steel fence, and pool area.

To improve drainage, we:

• Removed the existing mulch bed
• Installed five 6-inch catch basins
• Connected the system underground using 4-inch perforated PVC pipes
• Installed two underground dry wells for water dispersion
• Wrapped the drainage system with soil separators to reduce clogging risk
• Finished the area with decorative river rocks

This new drainage system helps move excess water away from the foundation before it can cause damage.

Mold Remediation and Waterproofing

Long-term moisture exposure had created visible mold contamination on plywood, flooring, and likely the concrete foundation wall behind the finished area.

Our licensed mold remediation team implemented full containment and remediation procedures, including:

• Installing plastic containment barriers
• Running HEPA-filtered negative air scrubbers
• Removing contaminated porous materials
• Cleaning and grinding affected concrete surfaces
• HEPA vacuuming and sanitizing all nearby surfaces
• Applying antimicrobial and fungicidal treatments

After the mold remediation was completed, we repaired the structural crack behind the contaminated area using epoxy injection and reinforced waterproofing cement.

The Result:

After the project was completed, the home had:

• Improved drainage around the basement staircase
• Fully waterproofed foundation and wall joints
• Stabilized structural cracks
• Reduced risk of future basement flooding
• Proper exterior drainage away from the foundation
• Mold contamination professionally removed and treated

The homeowner now has a safer, drier, and healthier basement environment protected against future water intrusion.

Why Homeowners in Syosset Choose Zavza Seal?

At Zavza Seal, we focus on identifying the true source of water intrusion problems before recommending repairs. Many basement leaks involve multiple connected issues, including drainage failures, structural cracks, and exterior water pressure.

Our team provides complete waterproofing solutions designed for long-term protection, backed by a 40-year waterproofing warranty.