Earthquake Retrofit - The drilling, sawing and nailing begin

The earthquake retrofit, the final costly project, started today! 

We were a bit concerned it would be delayed when we learned earlier this week that they submitted the wrong info for the permit. The city came through with approval of the correct one quickly though and there was no delay. Once the work is done and approved we can apply for a partial refund of our city transfer tax but you only have a year from purchase to do that. We should also get a discount on our earthquake insurance.

What is involved in an earthquake retrofit? For our home design it involves cripple wall bracing and foundation bolting. Our chimney would still likely fall down but addressing the chimney and its soft mortar is down the road as we don’t use the fireplace. The info below is from the California Earthquake Authority website. 

Cripple Wall Bracing

Cripple walls are short walls that rest on a house’s foundation and support the floor and exterior walls. When these walls are not braced, they may shift during an earthquake. When this occurs, the chances of severe damage to your house and injury to individuals increases. Bracing cripple walls strengthens structures by increasing stability, and the process typically helps minimize damage to houses. See the image above to understand how new elements in the crawl space enhance the house's earthquake resistance.

Foundation Bolting

Houses that aren't bolted to their foundation can move during an earthquake. Houses that move off their foundation will cause significant damage and may be costly to repair. The bolting process requires that holes are drilled through the sill plate on a foundation and anchor bolts are installed. Sometimes, there isn't enough space to drill, and steel plates will also need to be attached. These bolts must be properly installed to be effective.