Before you pick up the phone, consider whether your home needs a retrofit at all.
Here are some indicators that a retrofit is probably necessary:
Homes built before the mid 1980's often lack design elements that could make them earthquake damage resistant.
Homes built before World War II may not even be bolted to the foundation or the bolts may be too small and too few.
A quake could slide such a house right off its foundation.
An unreinforced garage with living space above is another danger sign.
That big garage door opening needs to be reinforced either by a steel frame of by strengthening the walls on either side or it can collapse in a shaker like a house of cards.
An unreinforced stone or masonry building definitely needs to be looked at. Unreinforced masonry construction is highly susceptible to earthquake damage.
These are some of the more obvious indicators. Reading through the whole guide will help you decide whether to call for help.
For a single family residence a contractor may be all you need. A contractor experienced with seismic retrofit will be aware of the standard issues and the standard engineered solutions. If you want an educated opinion about whether your home needs to be retrofit before you speak to a contractor, call an inspector who will charge a fee for the inspection.
For commercial, multi-family, or a single family with any of the conditions listed below we recommend that you call a structural engineer first. If the engineer concludes that retrofit is advisable the engineer will draw plans, then you'll call contractors to bid.
But if your home has any of these, start with the call to a structural engineer:
- two or more stories.
- any support posts, instead of walls.
- no foundation, or a block or brick foundation.
- an unusual shape.
- a location on a steep hill.
- living area over a garage.
- a porch that is recessed under a second story.
- a neighboring structure touching or almost touching.
Homeowners guide to earthquake retrofit
