Alpha Structural, Inc. Media Features

Hillside Foundation Repair in Los Angeles

Hillside homes in Los Angeles are prevalent with the terrain we have. It is important to note that hillside building codes have changed significantly over the years. Many of these homes built in the 1950s and 1960s were constructed with deepened foundation systems which (at the time of construction) were believed to be deep enough. Structural failures of these homes during El Nino winters and major earthquakes led to the more stringent foundation requirements of today.

Whether you live in a stilt home or a multilevel structure in the hillside areas of Los Angeles and surrounding areas, we can design, engineer and repair that structure. “Difficult jobs” with steep hillsides or limited access are exactly what we excel in. There is no home or hillside structure that we can’t repair. Our team and crews are highly trained for hillside repairs.

Hillside Homes Are Everywhere in Los Angeles

There are many factors that make the City of Los Angeles both unique and special to its residents. Among its natural resources, such as our beautiful beaches and great weather, the region’s hillsides and mountains are one of its most prominent features. In fact, there are very few areas in the Los Angeles region that are not defined by some sort of sloping terrain. Drawn by the natural beauty and spectacular panoramic views they provide, many of our most iconic neighborhoods have been built in our City’s hillside areas.

The classic image of a Hollywood Hills home on stilts is not always the norm, however. You may be surprised to learn that your own home may be zoned under hillside ordinances requiring specialized foundation repairs. As just one example, something called the “Baseline Hillside Ordinance” was adopted in order to establish new regulations that protect hillsides and the many communities that have sprung up among them.

Challenges Facing Hillside Residences: Earthquake Damage and Landslides

No matter where you are in Los Angeles, the fault lines are never far away. And for those who live in the hills, most of these hills were created by tectonic activity building up the terrain through the ages.

According to the Pacific Earthquake Engineering Research Center, the Northridge earthquake of 1994 created a surprising amount of damage to homes located on the hillsides of Los Angeles: of approximately 10,000 hillside homes, 374 were damaged, some severely.

What’s more, Los Angeles is particularly susceptible to mudslides and landslides. LA is well-known for prolonged periods of drought, so when the rain does come, it can be catastrophic for homeowners in the Hollywood Hills, Bel-Air, Beverly Glen, Elysian Hills, Montecito Heights or Palos Verdes.

For this reason, it’s imperative to ensure that hillside foundations and retaining walls are anchored to bedrock wherever possible. One effective way to do this is by using caissons and grade beams.

Caissons: What They Are, Why You May Need Them

Caissons, also known as piers or drilled shafts, are a type of foundation system where a deep hole is drilled into the ground, reinforced steel is placed in the hole, and new concrete is poured. The hole can be as much as 2 or 3 feet in diameter, and it can be drilled down as much as 60 feet in order to reach bedrock. In some cases, it may be acceptable to seat a caisson on thoroughly compacted dirt, but this is rarely the case in hillside scenarios.

Caissons are excellent for earthquake retrofitting a foundation, reinforcing stilt homes, or providing structural support for hillside retaining walls. They are capable of supporting heavy, concentrated loads in a variety of applications.

How Slope Angle Can Affect Your Home

Hillside foundation work can be done to expand the yard, expand the amount of space available for building, or to add on to the house. There can be structural reasons as well as cosmetic reasons.

City ordinances can actually prohibit the construction of new structures on extreme slopes, and it takes a company familiar with all the ins and outs to ensure your project doesn’t get bogged down in red tape.

The first thing to understand is that there are certain classifications specified by city ordinances to describe different degrees of slope:

  • 0° – 8.5° Flat to Moderate Slope
  • 8.5° – 16.7° Strong Slopes (true hillside)
  • 16.7° – 24.2° Very Strong Slopes
  • 24.2° – 31° Moderately Severe Slopes
  • 31° – 45° Severe Slopes
  • 45° or greater Extreme Slopes

These classifications are intimately connected with what you are and aren’t allowed to do with your property. For example, if you live on a hillside and plan on renovating and expanding the square footage of your home, strong or severe slopes could be limiting your options. It can even prevent you from increasing what’s called your “maximum residential floor area.”

An extreme slope of greater than 45° will require a Geotechnical Investigation Report—also referred to as a soil and/or geological report—which must include the most stringent level of geotechnical analysis and reporting feasible, and in sufficient detail to substantiate and support the design and construction methods being proposed.

Whatever the case, we have a number of solutions to help you change the slope of your property, allowing you to do what you want with your yard and home. Contact Alpha Structural, your Los Angeles hillside foundation repair experts today to get an assessment of what unique needs your hillside home presents.

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