Separation Between Foundation Wall and Sill Plate

A visible gap or horizontal slippage between the top of the foundation wall and the wood sill plate indicates the wall has rotated slightly under soil pressure, with the top lagging behind the bottom. The gap may admit daylight, pests, and cold air into the basement.

This is a structural warning sign that the wall is beginning to shear at the top. Carbon fiber straps anchored into the sill plate and footing restore the wall-to-sill connection and prevent further rotation. A NJ-licensed structural engineer should confirm the scope before repair.