The Problem: Foundation Settlement at One Corner of the Home

Foundation settlement doesn’t always affect an entire house. In many cases, movement is concentrated in one area where soil conditions have changed or where the existing support system is no longer adequate.

For this Vallejo home, engineering plans called for stabilizing one settled corner of the building through the installation of a new deep foundation support system. The project focused on strengthening the affected portion of the home while improving the overall level of the structure.

The Solution: Deep Reinforced Concrete Underpinning

Working from preliminary engineering plans prepared by Dave Olnes, Ward Construction installed eight reinforced concrete piers, each approximately 18 inches in diameter.

Unlike shallow support systems, these piers were drilled approximately 15 feet into the ground, allowing the structural loads of the home to be transferred to deeper, more stable soils. Reinforced concrete haunches were constructed to connect the new piers to the existing foundation, creating a strong structural connection between the original foundation and the new underpinning system.

Lifting the Foundation

Once the new underpinning system was completed, Ward Construction lifted the existing foundation from the new piers to make the affected area of the home more level.

Foundation lifting is often performed after underpinning has been completed because the new piers provide stable structural support during the adjustment process. While every home responds differently, carefully controlled lifting can often improve floor elevations and reduce the effects of settlement.

Strengthening the Floor Support System

In addition to stabilizing the foundation, the project included installing a new pressure-treated 4×12 ledger along the face of the foundation.

The ledger was designed to provide improved support for the ends of the floor joists, helping strengthen the connection between the floor framing and the newly stabilized foundation. Addressing both the foundation and its structural framing creates a more comprehensive repair than focusing on either system alone.

Engineering for Additional Site Improvements

The proposal also included an engineered option to construct ten additional reinforced concrete piers to help buttress an existing retaining wall on the property. In addition, deep fence piers were offered as a separate option for future improvements.

Although these were optional portions of the proposal, they demonstrate how structural foundation movement and site improvements are often evaluated together during a comprehensive engineering review.