If the building has not been retrofitted, an earthquake can cause serious damage to a home, especially. Retrofitting is the modification of a structure by adding new components to make the building stronger. Using the 1994 Northridge earthquake, the severity of structural issues in residential neighborhoods varied considerably from house to house dependant upon the steps each homeowner had come to fortify their residence.
Statistics show time and again that during seismic activity, houses which have been retrofitted can have less damage when compared to a home that hasn't been reinforced. This became the truth in the Long Beach earthquake of 1933, which resulted in the structural failure of brick buildings without reinforced masonry walls, including many school buildings in the region. Buildings with reinforced concrete had very little, if any, structural issues. In the aftermath of the magnitude 6.25 quake, California's Riley Act was adopted, which required local governments through the entire state to determine building departments and inspect newly constructed homes and businesses. During the years that followed, new building codes were implemented requiring the bolting of any wooden walls to the structure's foundation.
Especially in areas like southern California it is extremely important to consider the risks of earthquakes. As a way to minimize and prevent damage to a property throughout an earthquake, and the chance of the costly necessity for foundation replacement, it's important to consider earthquake retrofitting. Before, 50 years or more ago, buildings were mainly designed architecturally to endure one type of load-gravity, which only creates an up-and-down pressure or motion.
Recently, however, this has been widely recognized that a majority of earthquakes create pressures with a structure moving from side to side, creating a lateral load. Thus, older buildings, originally designed merely to adequately support gravity loads, may collapse because of the lateral pressure of your earthquake.
House bolting is a method of retrofitting in which a home is securely fastened for the foundation. It reduces the potential for earthquake damage by increasing the home's resistance to ground motion. Any house built ahead of 1950 that has not been retrofitted, will not be mounted on its foundation; it is actually simply resting around the home's concrete base. Within an earthquake, structures like these can readily slide from their foundation and collapse. A lot of the homes that fell from their foundation or were damaged during the Northridge quake were not bolted to the foundation.
Another way a home's structural integrity may be improved is simply by bracing cripple walls. A cripple wall may be the wall in between the first floor of the home along with the foundation. The walls make the crawl space which is often found underneath a house. Cripple walls are often only covered by exterior wood siding or stucco, and are considered the weakest component of a building. Bracing the walls with plywood boosts their strength and aid the prevention of your home from swaying in a quake. For more information please visit http://cal-quake.com/