Seismic Retrofits

Seismic Retrofitting

Seismic retrofit strengthens the connections between a house and its foundation using specialized hardware and engineering methods. In the event of an earthquake, it reinforces the structure of the house, using specially designed hardware and engineered constructions materials, allowing the dwelling to withstand much greater earthquake forces with much less structural damage. Two key terms commonly used in connection with seismic retrofitting are bracing and bolting.


Bracing is needed in wood houses that have cripple walls. Not all houses have a cripple wall, but if you go up a set of stairs to enter your home, you probably have one. Un-reinforced cripple walls are the weakest part of a house because they readily collapse in an earthquake. Bracing with plywood reinforcement on the inside face of the cripple-wall studs can save a dwelling from damage in future quakes.


Foundation bolting is needed when a house is not securely bolted to the foundation. Under the influence of earthquake forces, the foundation begins to vibrate even before the roof starts to move. If this happens, the entire building can literally slide off its foundation. This kind of failure can usually be prevented by ordinary foundation bolts and framing anchors.


  • Earthquake insurance typically carries a 20% deductible. retrofitting helps to reduce earthquake damages, hence it is worth much more than its cost.
  • Homeowners want to ensure the safety of their family.
  • Landlords want to avoid future loss of income from a vacant and damaged building.
  • Some earthquake and homeowners insurance require house retrofitting.
  • Proper disclosure about foundations are required before property transfers.

New homeowners: If your home is in Oakland or Berkeley, you may be eligible for a Transfer Tax Rebate on seismic improvements. We can guide you through the process. Safeguard your family and your property!