Slide 5 of 15
- All portions of the building, including those attached to the outside, experience horizontal earthquake forces.
- Most houses have one of these: porch, deck, exterior staircase, or some other type of framing attached to outside of the house.
- Few of the appendages are stiff or strong enough to resist the earthquake forces by themselves.
- They must be braced or adequately attached to the house to resist the earthquake forces.
- Figure shows a collapsed porch roof