can you run pvc in the drop cealing of a pleanum return?

[don_resqcapt19]

The issue of the toxic gasses from building materials is not really an issue, outside of "plenum" spaces. The volume of these items is very small when compared to the volume of materials used in the finishes and furnishings with in the building that produce the same toxic gasses.

 

[steve66]

I just finished up a three story office building. All the ceilings were plenum rated. Why can the plumber run PVC for his DWV, but I can't use any PVC in that same plenum rated ceiling???

My guess is that the plumber just hasn't got caught yet, or that the plumbing inspector isn't aware of a code section that prohibits PVC in a return air ceiling.

I know we did have issues with leaving PVC plumbing pipe in a return air ceiling during some remodels. The AHJ decided it didn't meet code when it was installed. However, they let it stay if we added smoke detectors above the ceiling.

Steve

 

[steve66]

Someone asked if you can always run plastic pipe in a non-return air ceiling. I think NEC 518 is one place where this is restricted.

Steve

 

[sparky59]

i wired a commercial building last year and all my wire had to be in metal. all my communication, computer, and coax cable had to be plenum rated. But, then the plumber comes in and runs pvc vent pipe in the ceiling....and the hvac ran plastic covered venting. i didn't get a chance to ask the state inspector why this was allowed.