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Re: Standard of Care

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Ron Martin wrote: 
 
>In answer to the brace rods on metal buildings, I know they do not take
into 
account any pretensioning to my knowledge.  The "assumption" is that they
will 
be installed snug-tite. < 
 
I am reviewing a submittal on a pre-engineered metal building right now. 
The 
drawings show rod bracing in the side walls; in one location the
"Instruction 
Manual" has a note which says to "obtain the proper tension" in the bracing
- 
but no definition of "proper tension" is given; in another location it
states 
to "loosen and tighten the x-braces as necessary to square the frame".  This 
is consistent with your statement that the braces are "assumed" to be 
installed snug tight, but no clear requirements are given.  
 
>Most metal buildings with a wall panel that has diaphragm ability are 
actually relying on that panel for bracing even though it was not designed 
that way.  As long as the panels are there and not cut-up with openings, the 
rods are not performing in much capacity. <  
 
This is true, although it is hard getting information on diaphragm
capability 
of metal panel systems.  I am also currently reviewing another project with
an 
existing pre-engineered metal building to determine the permissibility of 
removing several large portions of the siding for building modifications.  I 
confirmed with the building manufacturer that the building was designed for 
lateral load to be resisted by the bracing and neglecting the siding as a 
shear wall.  Last week a field inspection was done to confirm the existing
rod 
bracing locations.  The roof bracing was as designed, but the previous owner 
apparently decided to cut out all the wall rod bracing and throw them away 
(pieces of rod remain were they were cut).  It is a good thing wall panels 
actually have some shear capacity!