Determining plenum ceiling?

[DOcean]

Is there a "sure-fire" way to determine when plenum is to be used? I have been on several jobs and guessed incorrectly upon initial inspection as to yes/no on plenum.

I'm about to bid a large job and the existing wiring (mess) is non-plenum, however, I believe the ceiling is plenum rated.

???

Many thanks,

D. Ocean
VIP Video & Communications, Inc.
Miami, FLA

 

[franklin97355]

Take a look at the HVAC system. If the air is returned using the ceiling space without return ducts it's plenum.

 

[ttech]

Some municipalities require Plenum rated cable even if the ceiling space is Not used as a plenum. Check the local codes too.

 

[Servamatic]

Hopefully you have the blueprints, check the mechanical prints.
As franklin said, check for ducting on the air returns and in the ceiling.
Ask the HVAC contractor.
Ask the general.
In some areas I have worked the right on the sheetrock above the T-Grid line.

Richard S. Anderson, RCDD

http://www.servamatic.net

 

[hawks]

Also check with the building owner because I have ran into a couple of places that have PVC existing and are not Plenum jobs. But for whatever reason any new cable the in the building has to be Plenum according to the owner. Sounds like some cabling company had a good salesman if you know what I mean.

 

[hbiss]

Keep in mind too that all abandoned cables are to be removed. So, if that "mess" is not being used you will have to remove it.

Cable removal may be an even bigger problem in the future since it has been shown that the cable jackets contain lead compounds that "dust" after a few years. The owner (or the cabling contractor) will probably be required to contract with a haz mat company to remove this stuff. Think $$$.

-Hal