WHAT ARE THE PURPOSE THESE BLOCKS

[ARJ1]

When a shear wall is perpendicular to truss spans, shear blocks are specified over the shear wall. Sometimes I will see on the plans, this line of shear blocking continue pass the point of where the shear wall ends. My question is:

(1) Why is this done?
(2) Why is flat 2x blocking sometimes specified in lieu of shear blocks in situation question (1).(when I say "shear blocks" I mean blocks that are heightwise, spanning from the shearwall top plate to the roof or floor sheathing.)


Thank you for your help

 

[CJJS]

They are there to transfer the force from the roof diaphragm into the wall. This usually occurs with higher heel trusses.

 

[msquared48]

They are also there to prevent rollover of the truss ends.

They extend past the shearwall not only for the above reason, but to serve as shear transfer mechanisms to the drag force collector to the shear wall- the studwall double top plate, beam or header below.

FYI, the common term is just "blocking".

Mike McCann
McCann Engineering

 

[ARJ1]

THANKS CJ AND MIKE.

 

[ARJ1]

If anyone can recommend any reading material on this subject, I would really appreciate it.