PVC in drop ceiling

[shaw0486]

Is it acceptable to install PVC in a drop ceiling/plenum ceiling?

 

[fmtjfw]

depends on the occupancy and the job specifications:

single family residential probably ok (PVC and its cousin ENT)
place of public accommodation probably not.

If you have a barn with a drop ceiling, PVC is probably a good choice.

 

[kingpb]

If a fire occurs, burning PVC can emit large quantities of dense black toxic smoke, and significant amounts of hydrochloric acid. If you have a Plenum ceiling, having PVC in the ceiling during a fire would cause a concentration of these fumes to be spread throughout the building. Exposure to these fumes could then hinder the safe evacuation of persons in the vicinity and result in increased fatalities. The National Electric Code (NEC) requires that only plenum rated PVC cable be installed in plenum air spaces, I assume this goes for conduit as well.

 

[Jacob S]

I know this is a little OT, but I have always wondered. Why are plumbers allowed to run PVC pipe in a plenum space and we are not? Maybe it is technically not allowed, but I have seen many buildings where this was the case and inspectors haven't said a thing. Thanks!

 

[Joe Villani]

No PVC allowed

See (2008 NEC) 300.22(C)(1)