Plumbing Fixture Count - Penalty for mixed uses?

[nealderidder]

Such a rich and complex topic - toilets!

I'm ranting a bit - it seems like there is a penalty for having mixed uses. I'll just count women's toilets to keep it simple. Consider the following scenario:

A space with business and a small amount of factory use. Say 8,000 business and 4,000 factory.

Business: 8,000/200 = 40 occupants = 20 women = 2 W.C.
Factory: 4,000/2,000 = 2 occupants = 1 woman = 1 W.C.
Total women's W.C. = 3

The business use is more intense as indicated by the load factor (200 vs 2,000). So what if I classified the entire space as Business:

Business: 12,000/200 = 60 occupants = 30 women = 2 W.C.
Total women's W.C. = 2

So I'm allowed to provide one less women's W.C. just because I called it all business. Even if it really were all business, the count should go up if anything since business is a more intensive use.

Since I have to use the CPC table 422.1 there is a minimum of 1 W.C. for each use.

Is it legit to interpolate the numbers in 422.1? If I have an A-2 and my count is 26 (1 required up to 25, 2 up to 50) can I say that I need 1.0417 fixtures? Is that what 422.1 means by - "Where applying the fixture ratios in Table 422.1 results in fractional numbers, such numbers shall be rounded to the next whole number. From multiple occupancies, fractional numbers shall be first summed and then rounded to the next whole number."

If I can interpolate and then add up all the fractional numbers before arriving at a count then I've got nothing to rant about!

 

[RLGA]

Where are you getting your occupant load factors from?

Business: 8,000 sf/150 sf per occupant = 53 occupants

26.5 males = 0.53 fixture for the 26.5 occupants (26.5 occupants/50)​

26.5 females = 1 fixture for the first 15 and 0.76 fixture for the remainder (11.5 occupants/15)​

​

Factory: 4,000 sf/100 sf per occupant = 40 occupants

20 males = 0.40 fixture for the 20 occupants (20 occupants/50)​

20 females = 0.40 fixture for the 20 occupants (20 occupants/50)​

Per UPC Section 422.1, mixed uses are based on the sum of the fractional numbers and then rounded up:

Males = 0.53 + 0.40 = 0.93, round up to 1​

Females = 1.76 + 0.40 = 2.16, round up to 3​

​

​

 

[nealderidder]

Where are you getting your occupant load factors from?

Business: 8,000 sf/150 sf per occupant = 53 occupants

26.5 males = 0.53 fixture for the 26.5 occupants (26.5 occupants/50)​

26.5 females = 1 fixture for the first 15 and 0.76 fixture for the remainder (11.5 occupants/15)​

​

Factory: 4,000 sf/100 sf per occupant = 40 occupants

20 males = 0.40 fixture for the 20 occupants (20 occupants/50)​

20 females = 0.40 fixture for the 20 occupants (20 occupants/50)​

Per UPC Section 422.1, mixed uses are based on the sum of the fractional numbers and then rounded up:

Males = 0.53 + 0.40 = 0.93, round up to 1​

Females = 1.76 + 0.40 = 2.16, round up to 3​

​

​

So you are interpolating from the ranges in table 422.1. I'm never usually tight enough to have to worry about it but I'm trying to justify a count in a partially-remodeled TI (stopped half way through due to COVID). My load factors come from CPC table A which is what we use 90% of the time until we run into a jurisdiction that insists we use the egress count and load factors.

Thanks as always Ron!

 

[RLGA]

Is the project under the 2016 or 2019 California codes?