Originally Posted by
EmmanuelScanlan
The code changes excluded the use of PVC for drain pans and the 2006 reference now mandates CPVC for drain pans
Not 'the pan', the "drain line".
The pans already have to be metal ... 'or other approved material', which would include testing with hot water.
Using PVC for the drain lines from the pan to carry 'still hot water' is outside the temperature range of PVC.
The drain pan drain line does not need to be CPVC, it can be any material in the table I posted.
The Dec 2007 Building Safety Journal by ICC had a short blurb on this in the "Significant Changes To The 2006 I-Codes" section. It was explained that this occurred because, in a nutshell, the original specification was put in the wrong code section of the IPC. When they moved it to the "correct" code section it referenced the new table which excludes the use of PVC.
Close.
It was originally put in the T&P safety relief valve discharge section in 2003: (bold and underlining are mine)
- 504.6 Relief outlet waste.
- - 504.6.1 Discharge.
- - 504.6.2 Materials. Relief valve discharge piping shall be of those materials listed in Section 605.5 or shall be tested, rated and approved for such use in accordance with ASME A112.4.1. Piping from safety pan drains shall be of those materials listed in Table 605.4.
You will notice that the drain pan drain pipe is under the T&P valve discharge line section, HOWEVER, the same Table was referenced - Table 605.4 (referring to the IPC here).
When they relocated the reference for drain pan drain line to the drain pan section ... the referenced table *did not change* - Table 605.4.
The reason for the change, which is rather obvious, is that when you are looking up the requirements for the drain pan drain line, you look under the drain pan section, not the T&P section. In that sense, nothing really changed ... other than moving it to where people were looking for it. Which now makes PVC a not-suitable-for-drain-pan-drain-use pipe (actually was this way in 2003, just no one knew it because it was in the wrong section).
In the same little blurb they did indicate that this was a "controversial issue and must be resolved during the structure's design".
Actually, this is at the drawing as: A. The pan is installed to reduce structural damage from a water heater leak. Most code officials share the opinion that the pan is not capable of removing the pressurized discharge of a relief valve.; and, B. Drain materials shall be approved water distribution pipe, which would
NOT include PVC. (The "NOT" is in bold.)
Then it says: Note: Items A and B are controversial issues and must be resolved during the structure's design.
This is because, while "Most code officials" feel that way, not all do, nor do all architects and designers, thus, however, it is a code enforceable (mandated enforcement) item.
There was also additional wording that indicated they (ICC) are laying it back on the AHJ and installers to decide if PVC on a drain pan is acceptable.
Sort of, the drain pan is spelled out in the code as:
- 504.7 Required pan. Where water heaters or hot water storage tanks are installed in locations where leakage of the tanks or connections will cause damage, the tank or water heater shall be installed in a galvanized steel pan having a minimum thickness of 24 gage, or other pans approved for such use.
APPROVED. Acceptable to the code official or other authority having jurisdiction.
"Could" the AHJ approve a PVC drain pan? I guess, but all of the plastic drain pans I've seen were not PVC, they were ABS (or something else, just pretty sure they were not PVC).
"Could" the AHJ approved a PVC drain pan drain line? No, that is against code as it is spelled out what the code allows.
The main thing I got from that article was: 'Oops! We had it in the wrong section and no one saw it there.'
As far as the referenced table goes - nothing changed.
As far as the ICC code trick goes, few knew it was there, but now it is where all should see it, and, thus, PVC is no longer allowed for the drain pan drain piping.
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