There are several different rules to look at when trying to retrofit a property for seismic safety.
Dr.yellow, CC BY-SA 4.0, via Wikimedia Commons
When we think about staying safe in earthquakes, we consider the Richter scale measurements. Seismic retrofitting is a way of protecting a home using the base shear formula, which measures the force needed to collapse a property. The problem associated with seismic activity in California comes from homes shaking and coming to a sudden stop, with their momentum removing them from their foundations.
1. Check for Soft-Story Issues
How Stuff Works reports the retrofitting of some multifamily and single-family properties is vital to earthquake safety. The soft-story design flaw that came to light in California during the 1994 Northridge Earthquake caused the collapse of an apartment building. Design flaws can leave the first floor of a home susceptible to collapse because the lower story is weaker than those above. The momentum of lateral movement shakes the lower story until it collapses due to large windows, garage door openings, and open spaces. A retrofit will allow the soft-story to be made safe following a few days of work.
2. The Grandfather Approach
Building codes change each year and bring into force new rules about home maintenance and construction. Several counties in California allow a grandfathering approach to seismic retrofitting a property to be taken, which allows earlier versions of the building code to be applied. The concern of property owners considering retrofitting is how to stay within the strict building code guidelines. The guidelines associated with the building code do not always apply to an existing property when the local government allows grandfathering to take place. A grandfathering approach looks back to the time of construction and allows the property owner to remain within these guidelines.
3. Understand the Materials Already in use
The Getty Conservation Institute explains historic buildings in California were designed using clay materials, known as adobe. The use of adobe leaves a property owner with the issue of earthquake safety. The use of experts who are capable of assessing the potential damage of an earthquake is the starting point for property owners of this kind of home.
4. Understand Jurisdiction Issues
One of the first steps a retrofitting company will undertake is to explore the jurisdiction in which a property lies. Each property owner will need to understand the building code requirements of the jurisdiction of their home. The jurisdiction is an easy one to discover, with the experts in retrofitting understanding how the building code changes in each county of California.
5. Consider Gas Lines
Homeowners are often unaware of the problems caused by the utilities beneath their homes during an earthquake. A Seismic retrofit will examine the possibility of a catastrophic break in a gas line during an earthquake, This Old House reports. Installing an automatic shutoff valve when a gas line runs to a kitchen or heat source is one of the latest rules for a proper retrofit.
6. Use the Correct Brackets for Securing the Walls to the Foundation
In older homes, retrofitting professionals will look at the connection between the walls and the foundations. The construction of older homes rarely included the use of brackets to attach the walls to the foundation for earthquake safety. The use of L brackets is a rule of retrofitting in the 21st-century. Using the correct anchor screws and L brackets will allow the property owner to feel confident in their earthquake safety. The shaking of a building during an earthquake can move the structure off the foundation when the ground comes to a sudden halt. By installing L brackets, the state of California believes the property will have a reduced chance of collapse.
7. Think About the Interior of the Property
Seismic Retrofitting can include several options, including the securing of shelves and items to walls. A homeowner has the chance to keep their family safe by working with professionals who understand the dangers caused by falling objects during an earthquake. Anchors attached to furniture that could fall during heavy shaking are available, along with putty that will hold small objects on shelves during an earthquake.
8. Water Heaters Need to be Secured
There are several concerns for a property owner and retrofitting company that can be found beneath a home. After securing gas pipes with an automatic shutoff valve, attention can turn to the water heater. Water heaters can be located inside a property or in a crawl space, with the potential for damage when an earthquake hits. The concern over a water heater is not high on the list for many property owners who need to secure this appliance safely.The rules of retrofitting a property from earthquake damage are many and can lead to problems with a building. Employing a retrofitting company capable of following the rules and making a property safe is vital to securing the future of a property in California.