L. No Foundation Hold-Down Bolts
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III. Structural Problems and Strengthening
Methods L. No Foundation Hold-Down Bolts |
Hold-down ties are used to keep buildings or portions of them from turning over in an earthquake. Houses of average proportions do not tend to overturn or be lifted up, and hold-downs are usually not necessary. However, when the height of a house greatly exceeds its width, or when the house is on a steep slope, an engineer may recommend installing hold-downs (see Figure). Installation of hold-downs on the basement level is relatively simple since access is often possible in the crawl space. Only in rare circumstances will hold-downs be necessary on upper floors; installing them there will involve removing existing interior wall finishes and will cost more.
Typical Cost: $1000/house