Second the cripple wall or pony wall can fail.
Earthquake floor joists.
Look for out of plumb columns beams leaning to one side of the ends of beams separating from pockets in foundation walls.
First the sill plate can slide off of the foundation.
The horizontal lateral shaking in earthquakes create the forces that can be damaging to our wood framed homes.
Homes tend to fail in one of three ways all between the foundation and the first floor joists.
The building code makes no distinction between posts that are 2 feet tall or 10 feet tall and only requires one nail be used to attach the bottom of the post to the concrete block and nothing such as pier caps is required to attach the top of the post to the girder.
Around the outside of the floor system and the perimeter wall system is what is known as the rim joist.
Floor joists rest on top of the girders and the floor you walk on sits on top of the joists.
The connectors should be located approximately 16 inches on center.
The rim joist should be attached to the top of the wall with metal connectors.
Angle iron struts and foundation bolting a custom connection upgrade is to use angle iron struts which connect the floor joists directly to the foundation in a similar fashion to the simpson fja anchors.
On top of the crawl space wall rests the floor system.
In new construction a subfloor installed over a warped joist requires removal of the subfloor so.
Check the large beams that support the floor joists as well as the vertical columns or posts that support the beams.