Number of Toilet Fixtures for Mechanical and Storage

[Phil B]

I have a school facility with a mixture of occupancies: business, assembly, classroom, mechanical, and storage. I include the area of the mechanical and storage when figuring occupancy loads although I've seen opinions that these rooms should be counted as 0 occupants. When figuring the number of toilet fixtures required for these 2 occupancies however, and having to roundup before you add them together, I get an inordinate amount of toilets for what to some is considered 0 occupancy. In the case below I get 4 water closets for a small storage and mechanical areas. Do others usually consider that no toilets are required for Storage and Mechanical since that is not addressed in Table 403.1 in the Plumbing Code?

 

[steveray]

I don’t think you round up first…

 

[Phil B]

I don’t think you round up first…

This makes me think rounding first.

 

[RLGA]

Add them first then round up. Read the last sentence of IBC Section 2902.1.1.

 

[Phil B]

Add them first then round up. Read the last sentence of IBC Section 2902.1.1.

Awesome! Thank you! What's your opinion on providing toilets for Storage and Mechanical, minimum 1 for each, or 0?

 

[RLGA]

Awesome! Thank you! What's your opinion on providing toilets for Storage and Mechanical, minimum 1 for each, or 0?

I don’t provide a separate toilet for them—they are covered by the same toilet facilities the other occupants use, but their occupant loads are included in the total occupant load when calculating the minimum number of fixtures.

 

[Phil B]

I don’t provide a separate toilet for them—they are covered by the same toilet facilities the other occupants use, but their occupant loads are included in the total occupant load when calculating the minimum number of fixtures.

Yes, but if you are including them as a separate occupancy line item in the calculation, aren't you providing more than are needed than if for example you included the Mechanical and Storage areas in Business?

 

[Yankee Chronicler]

Please delete - not awake yet

 

[RLGA]

Yes, but if you are including them as a separate occupancy line item in the calculation, aren't you providing more than are needed than if for example you included the Mechanical and Storage areas in Business?

No, you will actually reduce the likelihood of additional fixtures:

For example:

For Water Closets:​

Business: 1:25 for the first 50; 1:50 for the remainder​

Storage: 1:100​

​

Occupant Load:​

Business: 296​

Storage/Mech: 5​

​

Calculation (Separate Occupancies):​

Business:​

1:25 for 50 occupants = 2.0​

1:50 for 246 occupants = 4.92​

Storage: 1:100 for 5 occupants = 0.05​

Total = 6.97, round up to 7 fixtures​

​

Calculations (Included with Business)​

Business:​

1:25 for 50 occupants = 2.0​

1:50 for 251 occupants (includes storage/mech) = 5.02​

Total: 7.02, round up to 8​

​

Some may argue about how far out to take the fraction, but I take it to two decimal points. Take advantage of those occupancies with better ratios than the main ones—they could be the difference between adding no additional fixtures or adding an additional fixture or two.

 

[Phil B]

No, you will actually reduce the likelihood of additional fixtures:

For example:

For Water Closets:​

Business: 1:25 for the first 50; 1:50 for the remainder​

Storage: 1:100​

​

Occupant Load:​

Business: 296​

Storage/Mech: 5​

​

Calculation (Separate Occupancies):​

Business:​

1:25 for 50 occupants = 2.0​

1:50 for 246 occupants = 4.92​

Storage: 1:100 for 5 occupants = 0.05​

Total = 6.97, round up to 7 fixtures​

​

Calculations (Included with Business)​

Business:​

1:25 for 50 occupants = 2.0​

1:50 for 251 occupants (includes storage/mech) = 5.02​

Total: 7.02, round up to 8​

​

Some may argue about how far out to take the fraction, but I take it to two decimal points. Take advantage of those occupancies with better ratios than the main ones—they could be the difference between adding no additional fixtures or adding an additional fixture or two.

Thank you!!