I was contacted by the contractor
for this professional complex in order
to salvage a situation that stemmed
from a long string of problems with
By the time I became involved in this
project, the contractor had so little
confidence in the sub that the first step
was a top-to-bottom structural
inspection to look for missing or
incorrect work. Several issues were
uncovered, from missing straps and
fasteners to permanent truss bracing
that was missing or installed in the
We knew going into the project that
there were problems with the truss
The subcontractor in charge of placing
the trusses decided to assemble the hipset
girder and hip jack trusses on the ground
and lift the entire assembly onto the
structure. This, by itself, is fairly typical.
In this case, however, the hipset girder
spans around 50 feet and the hip jacks
are nearly 30 feet long... and the
contractor decided to assemble this on its
side, with the hip jacks jutting up 30 feet
into the air.
After the assembly was complete, or
course, the subcontractor had to lift it and
rotate it so that it would lie flat on the
structure. Not surprisingly, this did not go
smoothly; the assembly fell over and
landed on several stacks of trusses
waiting to be assembled.
Several trusses were damaged and
replaced, while others were repaired.
Then the assembly was lifted into place.
Though the subcontractor
had supposedly sought
engineering to cover the repairs
made to the trusses, only a
single sketch stapled to a truss
was provided for the
ACS stepped in and
performed a rigorous
plate-by-plate inspection of the
entire truss assembly that fell
and found that there was far
more damage to the trusses
than had been addressed.
There were more than 30
significant structural problems
that were uncovered. A
sampling of the photos
recording this inspection are
shown on this page.
One example of a truss plate that was obviously damaged, but not
An example of a truss plate that was more subtly damaged. This
disconnect allowed the bottom chord to sag more than 1", though the
plate looked fine when viewed from the ground.
There is no damage here from the accident, but this picture shows that things do
not always go perfectly in the truss plant. Note how the near truss plate is offset
to the right from the truss plate on the far side (visible to the left). Making matters
worse, the web to the upper left has a rounded edge coming into this junction,
meaning this truss plate only catches an area the size of a postage stamp on the
web on this side.
One very lonely nail was found holding the truss in this hanger.
ACS Engineering provided a
report detailing specific items of the
structure that were either not
constructed to code or not
constructed according to the
architect's original plans. Specific
instructions were provided to
remedy the items.
ACS Engineering provided a
second report detailing the entire
truss assembly that fell. Every truss
plate and member amongst those
nearly 75 trusses was examined and
a determination provided indicating
whether the connection or member
was compromised or per the original
truss engineering. For each
compromised item, a specific fix was
provided, bringing each truss in the
assembly back to a state at least as
strong as its original design.
At the conclusion of this project,
the contractor had every confidence
that, in spite of all his issues with the
subcontractors, this structure was
sound and solid.