Town/Neighborhood: West Islip 

Borough/County: Suffolk County 

Construction Type: Residential 

Category: Foundation Repair, Structural Reinforcement, Waterproofing

Problem

The homeowner in West Islip, NY contacted Zavza Seal to address multiple foundation cracks in the crawl space walls. A total of ten cracks were identified, three of which were structural in nature and likely extended down to the footing. These extended cracks posed a serious risk to the foundation’s integrity and required specialized treatment to restore compression and tensile strength.

The remaining seven crawl space cracks, while not structural, still allowed moisture intrusion and weakened the crawl space’s protective envelope. The homeowner needed a comprehensive solution that addressed both crawl space waterproofing and structural reinforcement—inside and out.

Solution

Our team at Zavza Seal implemented a dual-phase repair strategy using high-performance materials and advanced structural techniques to restore the crawl space foundation.

Subject Area: 10 Structural Cracks in Crawl Space Foundation Walls

• We chased each crack to open a cavity surface suitable for repair.
• Loose materials were removed using steel brushes to ensure clean adhesion.
• Hydraulic cement was applied to fill each cavity and restore the wall’s surface.
• A coat of Sika 107 waterproofing cement was applied over the entire crack area to create a moisture barrier.
• While the waterproofing layer was still wet, we installed 4.5oz reinforced fibermesh to add tensile strength and prevent future cracking.
• A second coat of Sika 107 was applied to complete the repair on the seven non-extended cracks.

Note: This scope of work was performed on both the interior and exterior sides of the foundation wall. The only exception was the fibermesh, which was embedded deep into the concrete and did not require exterior installation.

Additional Work for the 2 Extended Structural Cracks

• We cut deep slots perpendicular across each structural crack at 12-inch intervals along the entire length.
• These slots were filled with structural epoxy to bond and seal the crack internally.
• Non-corrosive carbon stitches were embedded into the epoxy-filled slots. Each stitch is rated to withstand 6,500 pounds of force, restoring compression and tensile strength.
• This reinforcement method prevents future expansion and adds long-term structural integrity to the foundation wall.

Conclusion

This crawl space foundation crack repair project in West Islip, NY demonstrates Zavza Seal’s expertise in handling complex structural and waterproofing challenges. From sealing surface cracks with Sika 107 and fibermesh to reinforcing deep structural cracks with epoxy and carbon stitches, our team delivered a robust solution tailored to the home’s needs.

The homeowner was impressed with the precision and durability of the repairs. The crawl space is now structurally sound, moisture-resistant, and protected for decades to come.

Need help with crawl space foundation repair or structural crack reinforcement in West Islip, NY? Contact Zavza Seal today or call (631) 980-1800 now to schedule a free inspection and receive expert solutions backed by long-term performance.