Parsing UPC 507.5 Water Heater Drainage Pans

[wwhitney]

The 2022 California Plumbing Code, based on the 2021 UPC, has section 507.5 on drainage pans for water heaters. It begins:

"Where a water heater is located in an attic, in or on an attic ceiling assembly, floor-ceiling assembly, or floor-subfloor assembly where damage results from a leaking water heater,"

How exactly do you parse that?

It seems to me that without an "or" after the first comma, or other language indicating that "in an attic" is the first of a list of options, the rest of that phrase is an elaboration on which water heaters in attics the section applies to. Which doesn't make a lot of sense to me, but it says what it says.

Thanks,
Wayne

 

[Joe.B]

I don't read it that way. This is how I parse that sentence.

Where a water heater is

1. located in an attic,

2. in or on an:
2.a. attic ceiling assembly,
2.b. floor-ceiling assembly,
2.c. or floor-subfloor assembly

where damage results from a leaking water heater.

 

[wwhitney]

I don't read it that way. This is how I parse that sentence.

You didn't number the last clause (where damage results . . .), so let me call that 3. Then is your parsing: (1 or 2 or 3) or (1 and 2 and 3) or ((1 or 2) and 3) (since you didn't number the last clause), or . . .?

Regardless, none of those options would result in the wording we have. The only parsing I can see that matches the wording we have is effectively (1 and (2 a, b, or (c 3))).

Thanks,
Wayne

 

[Joe.B]

I did not number the last one 3 because I'm not reading it as another condition, I'm reading that as the conclusion of the sentence. Here's another way to look at it:

1. Where a water heater is located in an attic, where damage results from a leaking water heater.

2. Where a water heater is located in or on an attic ceiling assembly, where damage results from a leaking water heater.

3. Where a water heater is located in or on a floor-ceiling assembly, where damage results from a leaking water heater.

4. Where a water heater is located in or on a floor-subfloor assembly, where damage results from a leaking water heater.

 

[wwhitney]

OK, thanks. I think that it should be written a little different if the phrase "where damage results from a leaking water heater" is supposed to be a requirement in all cases, but I also think that's a reasonable reading and this distinction isn't my primary concern.

My bigger question is at the start: the sentence starts off "where a water heater is located in an attic, in or on (some list of supports)". What is the effect of that comma joining "attic" and "in or on (some list of supports)"? It seems to me it has the force of "and", not "or". So pans would only ever be required in attics.

It's like writing "where a car is located in a yard, on grass or pavement." The car needs to both be in a yard, and on grass or pavement. The effect is to exclude cars in a yard on some other material, say loose gravel.

In this case that's a bit odd, as what water heaters in an attic is the list of supports trying to exclude? Maybe the case of one suspended from the rafters? But that's a bit far-fetched.

However, if the intention were "or", they could just have written "in an attic, or in or on (some list of supports)." That seems like a stronger reason for the "and" meaning.

Cheers, Wayne

 

[Yankee Chronicler]

It should be obvious to all of us by now that the people who write the codes aren't grammarians.

 

[wwhitney]

OK, but I also think that intent is for the pan requirement to apply only to certain water heaters in attics. Otherwise why mention attics at all, particularly up front?

I mean if the idea was "Where a water heater is located in or on an assembly where damage results from a leaking water heater," they could just say that. And get there just by deleting words from the current word salad. : - )

Cheers, Wayne

 

[Mr. Inspector]

Does it matter if it is an instant water heater in the IPC? You would need a pan that is flat on one side to be against the wall that it is mounted too. Under the sink instant water heater pan could be a problem for accessible sinks.

 

[steveray]

Does it matter if it is an instant water heater in the IPC? You would need a pan that is flat on one side to be against the wall that it is mounted too. Under the sink instant water heater pan could be a problem for accessible sinks.

I believe the IPC says "storage" water heaters...

 

[Joe.B]

I would be willing to bet there are some different "schools" of thought on the proper use of commas. I have noticed situations similar to what you are describing on other code books too. In fact, I have copy/pasted code text into word documents and the spell-check has a hissy fit. I don't get hung up on it. I hear what you're saying, but I see through it.

 

[BN4537]

It should be obvious to all of us by now that the people who write the codes aren't grammarians.

And the plumbing code is the worst out of all of them in that regard.

 

[jar546]

The 2022 California Plumbing Code, based on the 2021 UPC, has section 507.5 on drainage pans for water heaters. It begins:

"Where a water heater is located in an attic, in or on an attic ceiling assembly, floor-ceiling assembly, or floor-subfloor assembly where damage results from a leaking water heater,"

How exactly do you parse that?

It seems to me that without an "or" after the first comma, or other language indicating that "in an attic" is the first of a list of options, the rest of that phrase is an elaboration on which water heaters in attics the section applies to. Which doesn't make a lot of sense to me, but it says what it says.

Thanks,
Wayne

Wayne, I see where the confusion lies, and you're right that the phrasing in Section 507.5 is a bit awkward. Here's how I would break it down:

The section seems to address water heater installations in various locations that could cause damage if they leak. The lack of an "or" after the first comma does make it less clear, but the intent appears to be listing different installation scenarios. Here’s my interpretation:

1. "Where a water heater is located in an attic": This applies to any water heater installed specifically in an attic space.
2. "in or on an attic ceiling assembly": This seems to refer to water heaters installed within or on the ceiling structure of an attic, which could be above a habitable space or another area below.
3. "floor-ceiling assembly, or floor-subfloor assembly": This is extending the rule to water heaters installed in or above a floor-ceiling or floor-subfloor assembly, meaning even if the water heater isn't in the attic, it could still pose a risk if installed above a space where leaks could cause damage.

While the language could be clearer, the section essentially lists different potential locations where a water heater might cause damage if it leaks, including attics, ceilings, and floors. It’s not limited to attics but applies to any area where a water heater is installed in or above parts of a structure that a leak could impact.

Does that make sense?

 

[bill1952]

some different "schools" of thought on the proper use of commas

Yeah. Dealing with this now on A117.1 editorial task group. ICC editors do not believe in the Oxford comma, and the task group overwhelmingly believes it's clearer with the Oxford comma. Doesn't help the ICC does not have a manual of style for its codes and standards.

 

[steveray]

Yeah. Dealing with this now on A117.1 editorial task group. ICC editors do not believe in the Oxford comma, and the task group overwhelmingly believes it's clearer with the Oxford comma. Doesn't help the ICC does not have a manual of style for its codes and standards.

Off topic, but a reminder to look at the 60” min. depth for ambulatory stalls vs. 56-59” for others in A117

 

[wwhitney]

OK, here's a little more info. The 2012 UPC text was:

507.4 Drainage Pan
Where a water heater is located in an attic, attic-ceiling assembly, floor-ceiling assembly, or floor-subfloor assembly where damage results from a leaking water heater, . . .

This was changed in the 2015 UPC to the current text

507.5 Drainage Pan
Where a water heater is located in an attic, in or on an attic ceiling assembly, floor-ceiling assembly, or floor-subfloor assembly where damage results from a leaking water heater, . . .

Does that make sense?

It makes sense as a possible intention (excluding that part about "on" being the same as "above", "on" implies contact), it doesn't make sense to me that anyone could translate that intention into the text we have. In fact, looking at the current text for probably the fifth time, the parsing that now makes the most sense to me is:

"Where a water heater is located in an attic, in or on an attic (ceiling assembly, floor-ceiling assembly, or floor-subfloor assembly) . . ."

That is the modifier attic applies all 3 assemblies listed. As otherwise you'd write

"Where a water heater is located in an attic, in or on an attic ceiling assembly, a floor-ceiling assembly, or a floor-subfloor assembly . . ."

And if the modifier "attic" applies to all 3 assemblies, the question of whether the first comma means AND or OR is moot.

Cheers, Wayne

 

[bill1952]

Off topic, but a reminder to look at the 60” min. depth for ambulatory stalls vs. 56-59” for others in A117

Isn't that a factor of width? Ambulatory in 35" wide?

 

[Yankee Chronicler]

Isn't that a factor of width? Ambulatory in 35" wide?

A117.1 Figure 604.10.1 and Section 604.10.2

An ambulatory accessible toilet stall is 60" minimum depth, and 35" - 37" wide. Not MORE than 37", because there are grab bars on both sides and if the stall is too wide some people can't use both grab bars.