Plumbing count for accessory occupancies

[PatrickGSR94]

I couldn't find a thread on here addressing this already. When you have a building of mostly one occupancy, with a small accessory occupancy (such as B office inside large S-1 warehouse), how are plumbing fixtures calculated? Per the main occupancy applied to the whole building (just S-1 in this case)? Or per each separate occupancy (S-1 areas/OL and B areas/OL)?

Does the IBC actually address this directly? Couldn't find it in either IBC 508 or in IPC Ch. 4.

 

[PatrickGSR94]

Nevermind, I'm guessing 508.2.2 about each portion of the code applying to each individual area's occupancy would dictate calculating fixtures separately for each area.

Right?

 

[Builder Bob]

Bingo.... however, a reasonable person might allow you to combine the calculations to keep from having one extra fixture = warehouse = 2.45 w.c. and business requires 1.35

IF you don't combine - then warehouse has 3 w.c. and business has 2 w.c for a total of 5, if you combine and the travel distance is OK, then you might be able to get by with 4.

i.e. 2.45 + 1.35 = 3.75 w.c

This will be a matter of interpretation by the building official or the AHJ. I have seen people round up and round down on these calculations.

 

[steveray]

Take the % or fraction of each by the fixture count table and add them together, I think the 2012 IBC clarified this for us...

 

[PatrickGSR94]

Bingo.... however, a reasonable person might allow you to combine the calculations to keep from having one extra fixture = warehouse = 2.45 w.c. and business requires 1.35

IF you don't combine - then warehouse has 3 w.c. and business has 2 w.c for a total of 5, if you combine and the travel distance is OK, then you might be able to get by with 4.

i.e. 2.45 + 1.35 = 3.75 w.c

This will be a matter of interpretation by the building official or the AHJ. I have seen people round up and round down on these calculations.

Yeah but what I was asking about was for example, applying the 1/100 for WC's in S-1 occupancy to the entire building including the accessory B, or apply 1/100 only to the warehouse portion and 1/25 up to 50 for the B portion and so on. And I believe the latter is the correct way. And like @steveray said I add the fractional numbers together, and then round up to get the final count.

 

[JPohling]

latter, combine and round up