Earthquakes are one of the few negative things that we have to expereince with living in California. Having you home fall off of it’s foundation or worse yet, having your building collapse is not something that you should experience and is something that you should have addressed.
Many of the raised foundations in California are not properly retrofitted. To properly retrofit a raised foundation home you need to make sure a few items are addressed.
Here are those items:
– Properly securing the home’s structure to the home’s foundation. This can be completed in 1 of 2 ways. One way is to simply drill through the home’s sill plate and into the home’s foundation. Then installing a poper anchor bolt into the whole and tightening the bolt. This step is repeated around the entire home. The second way is one we run into a lot, because of the limited head room within the crawlspace. This method utilizes an approved bracket, such as Simpson’s UFPB. This bracket connects to the side of the home’s sill plate and then anchored into the home’s foundation. Both methods work well, the height of your crawlspace will be the determining factor on which method is utilized.
– Secure all posts and pads. Making sure all of the posts and pads under your home are secured and strapped will ensure that your posts don’t slide out of place when an earthquake shakes the ground below your home.
– Secure the subfloor to the home’s framing. We utilize Simpson’s A35 clips to complete this step. These brackets are designed to make sure that the subfloor and the framing stay intact in the event of an earthquake.
Now there are more steps that are taken when you start to get into larger soft story buildings and other commercial structures. Moment frames and new footings are added to supply additional support of the loads above them. The moment frames also help to absorb the lateral forces during an earthquake.