Stilt Home Foundation Repair in Los Angeles
Seen all over the hills of Los Angeles, stilt homes were a trend during the late 1950s and early ‘60s as a way of developing steep hillside lots that were previously considered “unbuildable.” Many of these isolated stilt homes are scattered across the southern rim of the San Fernando Valley. If you are purchasing or selling a home in Los Angeles and would like to request a foundation inspection, please click here.
At the time, stilt homes were an inexpensive design and engineering solution to the problem of building on steep hillside lots. These homes are a subculture of Los Angeles with roughly 1500 of these buildings throughout the hills. However, these structures come with quite a few structural vulnerabilities:
Shallow Piles. With many of these stilt homes constructed around the 1950s, the hillside code at the time required what is now considered shallow piles. Overtime, these shallow piles were found to be insufficient to withstand the natural downward movement of the hillside.
Seismic vulnerabilities. The damage caused by earthquakes typically comes from lateral motion. These stilt homes usually are lacking in lateral support, such as shear walls, and thus are more susceptible to failure in the event of an earthquake. Additionally, the connection from the structure to the hillside is usually insufficient and puts the home in additional danger.
Weakened Structural System. Stilt homes were often constructed with the existing structural support system exposed. It’s to be expected that this can lead to loosened steel cables, rot of wooden stilts, rust of steel stilts, etc… This weakened structural system will need to be repaired to reinforce the structure and provide it with proper support.
Typically a stilt home’s support system consists of two or more stilts that are braced diagonally by rods or cables in an X-pattern, holding the floor of the house aloft. In some cases the floor beams were attached to the street-level foundation; in some cases not.
After the 1994 Northridge Earthquake, a study group of engineers was formed and identified stilt homes as the hillside homes “most vulnerable to earthquake damage.” Often times, the floor beams of the stilt homes that collapsed were not attached to its foundation. When the support system faltered, floors simply slid forward and down the slope.
As a result of the survey, the 1996 Los Angeles Building Code requires the floor beams of any new stilt home to be attached to street-level foundations. This requirement also applies to existing stilt homes undergoing reconstruction worth 50% or more of their value.
Call us today to schedule an inspection or request an estimateRequest an Inspection or Estimate »
Alpha Structural: Leader in Retrofitting
There are many stilt houses in hillside areas of Los Angeles and Hollywood Hills that feature spectacular panoramic terrain, but let’s make sure these iconic homes are retrofitted and safe from the next big earthquake. Alpha Structural has the team, the knowledge and the experience to ensure people’s safety and prevent property damage.
If you live in a stilt home, Alpha Structural can design, engineer and repair your home. Our highly trained and experienced team specializes in difficult jobs with steep hillsides or limited access. We will ensure the right retrofitting specific to your needs by anchoring your home for maximum stability.
The following list represents just some of the types of foundation repair we specialize in:
- Basement Waterproofing
- Brick Foundation Repair
- Concrete Foundation Repair
- Concrete Foundation Walls
- Earthquake Bolting
- Earthquake Retrofitting
- Foundation Inspection
- Foundation Repair
- Foundation Replacement
- Foundation Underpinning
- Grade Beams
- Hillside Foundation Repair
- Hillside Drainage
- Hillside Repair
- Hillside Waterproofing
- House Leveling or Sinking
- Non-Ductile Concrete
- Oceanfront Foundations
- Real Estate Inspections
- Retaining Walls
- Sister Foundations
- Soft Story Retrofitting
- Unreinforced Foundation