If you live where earthquakes have happened in the past or where they're likely to happen in the future, you probably want your building to be as secure as possible. However, older apartment and commercial buildings in some earthquake areas are not as safe as you might think. They were built before modern building codes came about that helped buildings keep standing during an earthquake. These old structures are called soft-story buildings. Here's why these buildings might not be safe, why you may want a soft-story retrofit done, and how your building might be repaired.
Why Soft-Story Buildings Are Hazardous
These structures are called soft-story buildings because the first story of the building is not as structurally sound as the rest of the building. That means during an earthquake, the upper floors could collapse and crush everything on the first floor.
This phenomenon can happen because of older building codes, using a lot of wood in the first story, and having wide open spaces on the first floor for a garage or retail space.
Why A Soft-Story Retrofit Is A Good Idea
A soft-story retrofit makes the first story of the building more stable so it has a better chance of standing longer during an earthquake. A retrofit isn't as strong as you would get with a new building since building codes for new construction are much more strict now. However, the retrofit makes a soft-story building much safer, and it could save lives.
Plus, some cities are mandating soft-story retrofits, or they may at least encourage them through various programs and regulations. For instance, you may not get a permit to remodel your building unless the plans also include a soft-story retrofit.
How A Soft-Story Retrofit Is Done
The retrofit process is different for different buildings since the first floors may be used for different purposes. However, the contractor needs to comply with local building codes when making changes so the structure of the building has a certain degree of safety improvements. Actions may include making walls stronger. For instance, the contractor might replace weaker drywall with plywood and then attach the walls to the foundation.
They might add walls and close the open space as much as possible, or they may add steel for support on the first floor. All of these changes require input from a structural engineer, architect, building contractor, and codes inspector. A soft-story retrofit can be a complex job and expensive to undertake, but it could mean the difference between life and death and the destruction of property during an earthquake.