The Problem:
Our team worked on a basement in Brooklyn, NY, where the homeowner had been dealing with mice entering the basement.
The main concern was the basement rim joists, where the foundation meets the first-floor framing. Small gaps, openings and utility penetrations in this area can provide easy entry points for mice and other small pests.
The basement also had a structural crack in the concrete slab measuring approximately 10 linear feet. This required a separate repair to strengthen the concrete and help prevent the crack from expanding.
Sealing the Basement Rim Joists
Our team focused on sealing approximately 102 linear feet of basement rim joists.
We first installed wire mesh along the rim joist to help block small animals from getting through openings. We then used SealTech Heavy Duty flexible foam insulation to air seal the rim joist area.
The foam was applied around the perimeter where the basement foundation meets the first-floor joists. All visible gaps, holes, wire penetrations and pipe penetrations were sealed to create a tight barrier.
We also inspected the rim joist from the exterior and sealed areas where additional air sealing was needed.
The goal was to close the small openings that could allow outside air, pests and moisture to enter through the rim joist.
Repairing the Concrete Slab Crack
The basement also had a structural crack running approximately 10 linear feet through the concrete slab.
To repair it, our crew first chased the crack with diamond blades and removed loose and damaged material around it. The concrete was ground approximately 3 inches on each side of the crack to expose a clean, solid surface.
We then created perpendicular slots across the crack at approximately 18-inch intervals. These slots were filled with structural epoxy, and non-corrosive carbon stitches were installed into the epoxy.
The carbon stitches help hold the concrete together and provide additional tensile strength across the repaired crack.
After the structural reinforcement was installed, we applied 6,000 PSI waterproofing cement over the repaired crack. While the first coat was still wet, 4.5-ounce reinforced fiberglass mesh was embedded into the cement. A second coat was then applied to fully cover the mesh.
The Result:
The Brooklyn basement received two important improvements.
The 102 linear feet of rim joist was air sealed and reinforced with wire mesh to help close potential entry points for mice and other small pests. The 10-foot structural concrete crack was reinforced with carbon stitches and covered with a reinforced waterproofing system.
The project addressed both the pest-entry concerns around the basement rim joist and the structural condition of the concrete slab, giving the homeowner a more secure and better-sealed basement.