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Cross-grain Tension Failures

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Dennis,

This doesn't answer your question, but I have seen cross-grain tension 
failures in ledgers only where the joist hangers are face mounted below the 
line of ledger bolts.  With top flange mounted joist hangers, the only 
cross-grain tension failure that I can see is from uplift and if the 
cross-grain tension strength is less than the strength of the nails.  If the 
top flange mounted joist hangers are rated for uplift, then I think that you 
are rightly concerned about cross-grain tension failure.

I have a top flange mounted joist hanger (about 20" deep) here in the office 
that I salvaged from a roof failure resulting from uplift.  The top flange 
has been opened to about a 135 deg angle (from 90 deg) and only two nails in 
the top flange connected it to the ledger.  I don't remember if there was any 
cross-grain tension failure in that building, however, in a nearby building 
and in the same storm, pre-engineered top chord supported wood trusses 
connected to nailers on a steel beam with H2.5/H3 type framing anchors had 
cross-grain tension failures in the top chord above where the framing anchors 
ended.

Hope this helps.

A. Roger Turk, P.E.(Structural)
Tucson, Arizona

Dennis Wish wrote:

>>I have inspected a reinforced masonry building constructed in the mid-50's
and located in Riverside County. There is a typical condition where the roof
joists are hung from a wood ledger bolted to the masonry wall. The joist
hangers are bearing from the top - creating a potential for cross-grain
tension failure.

The building (a bowling alley) is being converted to public storage,
although a small portion of it will be used as office suites. I have
informed the new owner of the potential problem and risk and have explained
the work that would be needed to correct the problem. He has no desire to do
the work.

I know that there is an ordinance to correct the problem with tilt-up
buildings but am unaware of any mandatory measures in California that would
require the owner to upgrade a reinforced masonry building (block or brick)
with a similar condition.

Can anyone advise me if there is any mandatory compliance in Riverside
County to retrofit the ledger/joist connections to prevent
cross-grain-tension failures in reinforced masonry buildings?<<