The intake nozzles on the Vesda fire detection system were pointed up and were getting clogged with dust.  We cut the nozzles off and inserted two 90 degree fittings so the nozzles would point down.  We needed to complete each pipe run before continuing to the next pipe.  This required us to travel across the trusses instead of following the truss.  We fabricated a 6 foot expandable bar that we could insert between the trusses and then slide across on “ladder hooks”.  This bar worked similar to the “pull-up” bars made to insert in a doorway – just much larger.

While doing this job we noticed a sprinkler head covered in moist slime.  It was above an area that not accessible from below.  We notified the sprinkler folds and replaced it when returned to finish up the job.