Residential Earthquake Retrofits in BC by Shear Seismic Retrofits

Garage Retrofits


Garages with living space above are another major cause of catastrophic earthquake damage

Lateral strength is everything in an earthquake and, looking at the picture to the right, you can see that the second storey living space is being supported by only 3 walls. Often these walls have window and door openings that may as well be holes in an earthquake.

Imagine if 12,000 pounds,  6 tons!, of earthquake force started shaking the shifting the ground back and forth. Suddenly, those garage walls can no longer support the violently shaking weight they are carrying. Anyone is this upper space is at risk.

Garage with living space above damaged by earthquake.

Life safety is definitely at risk when the garage supports a second storey of living space.  Without seismic reinforcement, the typical garage is simply too weak to support the weight bearing down upon it as the whole structure is being violently shaken in all directions.

If it’s lucky, it will remain upright but leaning. It’s a safer situation but still expensive to repair and immediately inconvenient. The house will be red tagged as unsafe to live in until a structural engineer says otherwise.

Eathquake damage to garage. Seismic retrofit would have prevented collapse.In a worst case scenario, the garage will totally collapse, leaving the second story flat on the driveway. Hopefully no one was inside the home at right. It will be torn down and the family won’t have a home to come back to for years, if at all.

Even with earthquake insurance, many Californians ended up abandoning their destroyed homes. Insurance claims took years to settle and there was still a mortgage to pay along with everything else. There was nothing left to cover a massive deductible. It’s four and a half years since the Christchurch earthquake and many there still have unsettled claims and no homes. It isn’t a situation anyone wants to find themself in.
Leaning single storey garage did not have a seismic retrofit to prevent earthquake damage

Garages with NO living space above

A garage without living space above is not at similar risk given all it supports is a roof. If anything at all, it is most likely to end up leaning, as shown at right. It is still expensive to repair but not much of a risk to life safety.

Retrofitting a Garage

There are a few options and it depends very much on the configuration of the structure. You maybe be able to get quite a lot of benefit from shear walls if there is enough space available. In other instances it may require steel reinforcement. As with all retrofits, we find the best options we can for you according to the investment you are able to make.