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Pre-engineered truss joint connector plate is separating from truss...
2

Pre-engineered truss joint connector plate is separating from truss...

Pre-engineered truss joint connector plate is separating from truss...

(OP)
I recently viewed an existing retail plaza (Tampa, Florida US) where the roof is "sagging" in multiple locations.  After some inspection it appears that the wood trusses may be overloaded in said locations due to HVAC equipment and a hot water tank.  At this location there is a truss plate at a bottom chord splice location which is also a truss panel point.  At this joint there are two of the factory installed truss plates, one of which is pulling apart from the truss (1/4" separation).

What is the typical repair procedure for such issues?

My intention is to have the truss analyzed and design a pair of steel plates to be installed over the failing plate.  Has anyone ever encountered this issues and/or have any recommendations?

Thanks,
 

RE: Pre-engineered truss joint connector plate is separating from truss...

Sister the failing truss with one on each side of the existing one. Use through bolts at the plate repair.  Replace blocking and bridging.

RE: Pre-engineered truss joint connector plate is separating from truss...

That condition usually indicates that the truss plate is overloaded or was too small to begin with.  Typical failure looks like it is "peeling" off the wood.

Certainly, added HVAC and humidity may have contributed to this problem or possible under design.

Can you find original truss fabricator and truss plate mfg??

They could/may help.

Are the wood members pulling apart??.  If so, you might need to shore up and sister the joints.  How to do that depends on the member sizes, configuration, loads, etc, etc.

Dr Frank Woeste at Virginia Poly teaches a course on this very subject and I believe he has written a book or white papers on this.  You could Google him and try to contact him. He occasionally shows up in this forum.  You might search.

Good Luck

RE: Pre-engineered truss joint connector plate is separating from truss...

As has been mentioned, the truss is failing, and must be repaired right away.  The entire truss needs to be evaluated, since that once the failed joint is repair another area of the truss may fail.  It is possible other joints, the webs, and chords may need to be reinforced, also.

A typical repair depends on the added loads on the truss, the original truss design, and the amount of damage to the trusses. It may be as simple as reinforcing the metal connector plates at the joints and adding scabs, or sistering another truss to the existing may be needed.

No matter the repair, if they want to remove the sagging, they'll need to shore up the existing trusses temporarily until the repairs are complete.

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