21st Century Home Improvement Painting & Roofing

off of its foundation.

To prevent this, the mudsill must be bolted to the foundation properly (see step 2). The walls between the foundation and the floor of a home, called cripple walls are a second problematic area. The shear forces during an earthquake often cause the cripple wall to collapse. To prevent this, the cripple walls must be braced with plywood and nailed correctly. (see step 6) The third area that commonly fails during major earthquakes is the connection between the cripple walls and the floor of the home. In order for a retrofit to be effective, all of these areas must be strengthened. 21st Century Home Improvement Painting & Roofing strengthens each of these areas to assure that the effectiveness of our retrofits is maximized. We also encourage you to educate yourself and your family about earthquake preparedness by contacting agencies such as the Red Cross and FEMA.

Seismic Retrofitting Process

1. Remove all shelves, work benches, and other items from walls to gain access to work areas. Return these items to original locations when work is complete.
2. Drill 5/8" holes through mudsill and concrete foundation, approximately 8" deep, every 4', and 1' from each end. Vacuum dust from holes, fill holes with Epoxy, and install bolts in holes. Allow 24 hours for Epoxy to set. Once Epoxy has set, tighten nuts and washers into place.
3. In areas where there is limited access for drilling, install Universal Foundation Plates every 4'.
4. Supply and install hold-downs to each outside corner where accessible.
5. Post to Beam connections: supply and install steel "T" brackets with Machine bolts.
6. 1/2" plywood sheer wall: supply and install 1/2" CDX plywood, connecting mudsill to double top plate. Nail in place with 10-penny nails every 10" field and 3" edges. Drill 1-1/2" holes in each bay for ventilation.
7. Remove all debris and clean up.

One of the few downsides to living in the Bay Area is the omnipresent threat of a major earthquake. Seismic retrofitting is one of the few steps a homeowner can take to prevent damage to their home when the next big one hits. Unfortunately, there is no way to guarantee the safety of one's home and family in a major earthquake because the size and motion of an earthquake is unpredictable. However, a properly executed retrofit can often minimize or even eliminate structural damage to your home.

An effective seismic retrofit addresses three potential problems areas in the structure of your home. First and foremost is connection between your home and the foundation. The lateral (shear) force created during an earthquake often causes the home to slide