Town/Neighborhood: Jamaica
Borough/County: Queens
Construction Type: Residential
Category: Foundation Repair, Foundation Wall Restoration

Problem:

The General Contractor had excavated the basement floor to gain additional ceiling height. However, this aggressive excavation work led to severe structural issues. Portions of the foundation walls completely collapsed, while the remaining sections were at high risk of failure. Immediate underpinning and foundation wall restoration were required to prevent a total collapse of the structure and further damage to the home.

Additionally, we discovered two large structural cracks in the existing foundation walls. The cracks not only compromised the structural integrity of the house but also allowed water infiltration due to previously improper waterproofing methods.

Solution:

Work Area A: Collapsed Section of the Damaged Beyond Repair Wall (approx. 22 linear feet)

Our team began by carefully demolishing and disposing of the collapsed and partially collapsed foundation wall sections. To ensure the safety of the structure during demolition, we used phased removal methods with proper shoring to stabilize the 1st and 2nd floors, as well as the adjacent concrete walkway.

We proceeded with installing a new 24-inch deep by 18-inch wide reinforced concrete footing. This footing was also phased to maintain shoring and structural stability throughout the process. Once the footing was in place, we constructed a new waterproof cinder block foundation wall, integrating our proprietary waterproofing technique to seal the exterior below-grade section, despite the lack of direct exterior access.

Work Area B: Entire Perimeter Excluding Work Area A (approx. 94 linear feet)

To address the compromised perimeter foundation, we excavated the entire area deep enough to allow for safe and effective concrete formwork installation. We compacted the soil meticulously to provide a firm base and installed #5 rebar every 15 inches, driving them 5 feet deep into the ground to function as piles.

For added structural integrity, we installed continuous horizontal reinforcement using #5 rebars across the full length of the new footing. We then formed and poured a reinforced concrete footing, measuring 24 inches deep and 18 inches wide. All work was staggered in phases to ensure that the structural integrity of the house was never undermined during the process. The footings were poured with 4,000 PSI concrete to ensure durability and strength.

Structural Crack Repair: Subject Area: 2 Large Cracks in Foundation Walls

In addition to the foundation reconstruction, our team addressed the two large structural cracks in the remaining foundation walls. The repair process involved:

• Chasing and grinding the crack areas using diamond blades to remove contaminants, defective materials, and expose clean bare concrete.
  
• Drilling into the cracks to install access ports for precision injection.
  
• Injecting urethane and epoxy formulations into the cracks to restore structural integrity and create a permanent seal.
  
• Applying the first coat of Basecrete waterproofing cement to the cleaned surface.
  
• Installing a 4.5oz reinforced fiberglass mesh from Basecrete to strengthen the repair area.
  
• Completing the process with a second coat of Basecrete waterproofing cement for a robust and long-lasting waterproofing solution.

Conclusion:

This foundation repair and underpinning project in Jamaica, Queens, NY, showcased the expertise of our team in handling complex structural challenges under tight constraints. From phased underpinning to advanced crack injection and waterproofing, every aspect of this project was executed with precision to restore the home’s foundation and protect it against future damage.

If you’re facing foundation issues in Queens or anywhere in New York, trust Zavza Seal’s expertise in foundation repair, underpinning, and waterproofing. Contact us today for a free consultation and protect your property with solutions that last.