Problem

A homeowner in Brooklyn contacted Zavza Seal after noticing a long structural crack in their concrete floor slab. The crack was about 16 linear feet and showed signs that the slab was under stress. The homeowner was concerned that the crack could grow larger and lead to structural problems or water intrusion in the basement.

During our inspection, our team also noticed another issue. The interior foundation walls had been coated with liquid rubber by a previous contractor. This type of coating can trap moisture behind the wall. When water pressure builds behind the foundation, it can cause new cracks, surface damage, and deterioration over time.

The property owner wanted a long term repair that would stabilize the concrete slab and protect the foundation from further damage.

Solution

Our team at Zavza Seal created a structural crack repair and foundation waterproofing plan designed to stabilize the slab and restore the integrity of the basement.

First, we prepared the structural crack for repair. Our technicians chased and ground the entire crack using a diamond blade. This allowed us to properly open and clean the crack so the repair materials could bond strongly to the concrete.

Next, we installed carbon fiber stitches along the crack. These stitches were embedded in structural epoxy and placed across the crack to restore tensile strength. Carbon fiber reinforcement helps stabilize the slab and prevents the crack from expanding further.

After the carbon fiber was installed, we drilled access ports every 12 inches along the crack. This allowed us to inject the slab with professional grade urethane and epoxy formulations. The injection process filled any hidden voids and sealed the crack internally to stop water and strengthen the concrete.

Once the injection was complete, we installed a multi layer waterproofing system using Basecrete waterproofing cement. Our process included:

• Applying the first layer of Basecrete waterproofing cement to the repair area
  • Installing reinforced 4.5 oz Basecrete fiberglass mesh for added durability
  • Applying a second layer of Basecrete waterproofing cement to fully seal the surface

For the foundation walls, we recommended removing the existing liquid rubber coating. Interior liquid rubber can trap moisture and make the wall unable to breathe, which increases hydrostatic pressure and can lead to further cracking. After removal, any additional cracks or issues in the foundation will be properly addressed with breathable waterproofing materials.

Result

The structural crack was fully stabilized using carbon fiber reinforcement and professional epoxy injection. The waterproofing layers now protect the slab surface and help prevent water intrusion in the future.

By correcting the improper liquid rubber coating and using proper waterproofing materials, the foundation can now release trapped moisture instead of holding damaging pressure behind the walls.

The homeowner now has a safer and more stable basement with a long term structural repair solution.

Why Carbon Fiber Crack Repair Works

Carbon fiber reinforcement is one of the most reliable methods for repairing structural cracks in concrete slabs. It restores tensile strength and helps prevent cracks from spreading under structural loads.

If you are dealing with structural cracks or basement moisture issues in Brooklyn, Zavza Seal provides professional inspection and long term repair solutions.