SEISMIC SAFETY

Seismic Safety

Bad Examples

HOME REFERENCES HOW SAFE ARE YOU RETROFIT BASICS CRIPPLE WALLS SAGGING FLOORS RECENT QUAKES
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HERE ARE SOME EXAMPLES OF JOBS THAT HAVE BEEN DONE INCORRECTLY

                   

                    SOUTH PASADENA:

Improper nailing pattern for plywood shear panels; sill plate blocking was not installed prior to plywood installation. Note the lack of perimeter edge nailing at the sill. Also note that ordinary ½” plywood was used on these short 4” cripple walls. Four inches is insufficient room to properly install the required blocking, therefore another critical aspect was ignored by this "community minded" contractor who is always on the job to see that the customer gets his moneys worth.

This view shows additional evidence of disregard for required cripple wall bracing.

Note the absence of required blocking and hardware.

Note that there is no method of connecting the upper plate to the foundation.

 

This picture shows improper edge distance for foundation bolts. The bolts were drilled at an angle to avoid block material under the sill plate. Also note additional improper nailing and lack of shear transfer at the panels above the foundation.

 

 

                    EAGLE ROCK:

 

This photo highlights the absence of connectors which would be required in the transfer of earthquake loads to the anchored sill. Interesting that this contractor postures himself and his wife as a community minded team dedicated to safety for senior citizens, schools, churches, zoos, and animal shelters. He further boasts that unlike other contractors he oversees all of his work. These photos are the documented results of his personal touch.

 

Contractor properly installed plywood, vents, nails, and blocking for this cripple wall. Any investigator should ask why does contractor omit required joist blocking and framing anchors above the plywood?

 

Why would this contractor brace the wall in the photo above and then leave these walls unprotected? Could it be that the work space in this area of the home was difficult? Who would suspect that the good contractor would leave this work out just because it is hidden from easy viewing?

 

 

                    GLENDALE:

These lag bolts were hurriedly screwed in without the benefit of a predrilled pilot hole. This "time-saving" method split the sill plate rendering the bolts useless.

These bolts were placed in hole that was too big for the bolt. This method made it quick to just drop the bolts in the hole. Who would be the wiser if they didn’t put a wrench to each bolt. We were able to lift these bolts out easily with our finger tips.

This quick installation of slapping up a piece of plywood offers little resistance to lateral forces.
    

1. The nails don’t cinch the plywood to the nailing       surface.  

2. There is no required blocking.

3. In a strong seismic event these nails would simply  bend over and allow the cripple wall to collapse.

Here is another example of bolts being placed in a large hole. The bolts do not serve their design function. Again we were able to remove these bolts from the foundation with our bare fingers. This installation offers no resistance to an earthquake.

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Seismic Safety - Ed Sylvis Construction
1410 North Lake Avenue
Pasadena, California 91104