Earthquake Preparedness Issue:
Earthquake Retrofits: I’m Bolted, I’m OK?
I hear from way too many folks who have looked in their crawl space, seen some bolts connecting their “mud sill” to their foundation, and think “Oh, good, my foundation is bolted, I’ve got a retrofit.”
A “bolted foundation” is NOT a retrofit. It is an essential ingredient of a retrofit, yes, but there is another ingredient (transfer ties) and very often a third (shear panels) which are also essential.
If your foundation is bolted, it just means that the mud sill will probably stay put during a serious quake. The house, however, could very easily fall off the foundation. All three things must be done correctly, and all too often they are not.
Be sure – have your retrofit checked (it may be incomplete or even incorrect). You can choose:
- A licensed contractor, who may or may not know what they are doing (and have a financial interest in the outcome); or
- A structural engineer: some won’t even crawl under a house, and those that do, I’m told, charge $400 and up; or
- Larry Guillot of QuakePrepare. I’m the only earthquake preparedness expert who does in-home consultations. The consult covers an assessment of your home’s attachment to the foundation, but also much, much more. Click on my website below. Also check out the SF Chronicle article on my consultations:
http://www.sfgate.com/living/article/Quake-preparedness-consultant-seeks-to-save-homes-2437241.php
Photo of Larry checking house seismic attachment to the foundation
Feel free to forward this Tip to three friends!
Be safe.
-Larry
QuakePrepare
Larry Guillot
707-965-3299
https://www.quakeprepare.comemail: larry@quakeprepare.com
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