Foundations are critical to a home’s stability and safety. Over time, certain foundation types can develop problems that, if left untreated, could compromise the structural integrity of a house. Below are three foundation types that can be particularly problematic for homeowners and what can be done to repair or replace them.
1. Brick Foundations
Brick foundations, common in homes built in the late 19th and early 20th centuries, are made by stacking and mortaring bricks to form a foundation wall and were used in early U.S. home construction, including in the Los Angeles area.
However, Southern California’s susceptibility to earthquakes revealed that brick foundations do not perform well during seismic activity. As a result, by the early 1920s, brick foundations were phased out. Despite this, many homes built before this change still have brick foundations, especially in areas like Pasadena, Hancock Park, and Downtown Los Angeles, where older homes are prevalent. While sturdy for their time, they can be prone to significant issues today.
Why They’re Problematic & How to Fix Them
Over time, the mortar between the bricks can deteriorate due to moisture infiltration, age, and environmental exposure. This leads to cracking, loosening of the bricks, and a weakened foundation. Brick foundations are also more vulnerable to earthquakes because they lack the flexibility needed to handle ground movement. In severe cases, the entire foundation may need to be replaced. This involves rebuilding the foundation altogether, ensuring it meets modern structural standards.
2. River Rock Foundations
River rock foundations, commonly found in older homes, are made by stacking large, rounded stones with mortar to form a base. These foundations can look charming in historic homes, but they come with significant structural risks. In Pasadena, Altadena, Sierra Madre, and surrounding areas, river rock foundations are still common in older homes. However, due to their poor structural integrity and vulnerability to seismic activity, the only lasting solution for these foundations is a full replacement. This ensures the home meets modern standards and is better equipped to handle earthquakes, which are common in Southern California.
Why They’re Problematic & How to Fix Them
River rock foundations are unstable because the rocks are often irregularly shaped and difficult to bind tightly together. The mortar used to hold the rocks in place can degrade over time, allowing water to seep in and cause further deterioration. As the foundation weakens, the home can experience settling, cracking, and other structural issues.
Due to the inherent instability of river rock foundations, repair is often challenging. In many cases, the best solution is to replace the foundation entirely. A common approach is to retrofit the river rock foundation by installing a new concrete foundation underneath or a sister foundation adjacent to the existing one. This stabilizes the home and prevents further damage from moisture and settling.
3. Low-Rise Foundations With Cripple Walls
Low-rise foundations with cripple walls are common in homes built from 1900s to 1940s. These walls are short wood-framed structures that sit between the foundation and the floor of the home, creating a crawl space.
Why They’re Problematic & How to Fix Them
Cripple walls can be vulnerable to shifting or collapsing during seismic activity if not properly braced. They are also prone to moisture issues, which can lead to wood rot, mold, and pest infestations. Over time, this weakens the structural integrity of the home and can cause uneven floors or even foundation failure.
To address issues with cripple walls, seismic retrofitting is often necessary. This involves reinforcing the cripple walls with plywood and steel brackets to ensure they can withstand lateral movement during earthquakes. Additionally, any moisture-related damage should be addressed by assessing any drainage issues and replacing damaged wood to prevent further rot.
Brick, river rock, and low-rise foundations with cripple walls all present unique challenges for homeowners, particularly in older homes. Regular inspections and timely repairs are essential to maintaining the structural integrity of these types of foundations.
If you suspect foundation issues or have an older home with one of these foundation types, you can schedule a foundation inspection to determine whether repairs or a full replacement are necessary. Proper maintenance and reinforcement can prevent costly future repairs and keep your home safe and stable for years to come.
