Oh those long blue wires bring back bad memories. Back in the '90's our state had a program to wire all schools for internet and put a computer in every classroom. As per typical, contractors bid on the job to wire the school buildings. The guy that won the contract for our school seemed nice enough, was easy to work with etc. One day as the project neared completion, we asked how much it would cost us to add something not on the original contract. He told us that he was making so much money on this job that he would just do it for us. He went on to say that the reason he made so much is that he bid the job using "plenum rated" cable as specified in the state specifications. He said that he discovered our ceilings were not plenums so he used regular cable.

FYI, "*General Purpose cables have no fire rating. These are not comparable to Riser or Plenum cable jackets because when General Purpose cables burn they release smoke and toxins, as there are no fire safety aspects to these cables. General Purpose cables are suitable for residential or one-story uses only."

He was not all all happy when I informed him that indeed most of our ceilings were return air plenums. Not every place, but in many places. He had only check one ceiling on an old, 1910 vintage, building. Needless to say, we did not see him again, the state had to hire someone else as the state was suppose to be inspecting the work.

ALL of that pretty blue cable ended up in the dumpsters outside all of our 11 school buildings. Miles and miles of Cat 5 cable.