Joist Blocking in Cantilevered Floor Joists

This is one more reason FEMA P-1100/ICC 1300 is so expensive. Some houses have cantilevers extending a few feet over the cripple wall.  In these cases, some kind of system needs to be developed to keep the floor joists from rolling over.  This video looks at a blocking system applicable to houses where the floor joists are supported by the cripple wall.  

This will often be a bay window, a love seat, or sometimes an extension of the kitchen.  It is very impost to give special attention to these areas of the house because the joists are cantilevered which makes it impossible to connect the floor to the top of the cripple wall.  FEMA P-1100/ICC 1300 provides one way of doing this. Joist Blocking Drawing in Guideline Retrofit of One and Two Story Dwellings

Joist Blocking Detail in FEMA P-1100/ICC 1300

The “Connector Type G” seen in the detail above is the Simpson Strong-Tie LTP 4.  This is an adequate method of addressing cantilevered floor joists but in order for it to work the top plates need to be joined together with nails extending through the lower top plate into the upper top plate.   This is explained in the video. 

Joist blocking drawing by structural engieer


This is a unique system that relies on the strength of a glued connection rather that a nailed connection.  Generally glued plywood to framing connections are avoided because glue lacks the ductility of nails and might snap.  In some cases, you don’t have a choice.

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