Metro Detroit renter guide
Michigan Construction Site Toilet Requirements Explained
Michigan sets its own toilet count for construction sites. Here is the rule, how it compares with federal OSHA, and how to size a real crew.
By Roman, owner. Reviewed October 13, 2026
How many toilets does a Michigan construction site need?
A Michigan construction site needs 1 toilet for 1–20 employees, 2 toilets for 21–40 employees, and 1 additional toilet for each additional 40 employees or fewer, under Michigan Administrative Code R 408.40129. A site with 85 workers needs 4 toilets: 2 for the first 40, 1 for workers 41–80, and 1 for workers 81–85.
| Workers | Michigan minimum |
|---|---|
| 1–20 | 1 |
| 21–40 | 2 |
| 41–80 | 3 |
| 81–120 | 4 |
| 121–160 | 5 |
Source: Mich. Admin. Code R 408.40129, Toilets at construction sites.
How is the Michigan rule different from federal OSHA?
The Michigan rule counts toilets only, while federal OSHA 29 CFR 1926.51(c) Table D-1 counts toilets and urinals together: 1 toilet for 20 or fewer workers, 1 toilet and 1 urinal per 40 workers for 20 to 199, and 1 toilet and 1 urinal per 50 workers for 200 or more. Michigan employers follow the state MIOSHA standard.
Most standard porta potties include both a seat and a urinal, so one standard unit satisfies the federal “toilet and urinal” pairing in practice. The Michigan count is the one inspectors use on Michigan jobs.
Source: OSHA 29 CFR 1926.51.
Need units now? Call (313) 476-6006 by noon, Monday through Saturday, for same-day delivery in Detroit and nearby suburbs.
How often must a job site porta potty be serviced?
Michigan rule R 408.40129 says toilets must be serviced and maintained on a regular basis and supplied with toilet paper, without naming a frequency. Weekly service is the industry standard for a crew within the rule’s count. Crews working 6 days, long shifts or near the per-unit limit should add a second weekly service.
- 1 unit, up to 10 workers, 5 days: weekly service.
- 1 unit, 15–20 workers or 6-day weeks: twice weekly.
- Food on site or lead, paint or chemical work: add a handwashing station.
Are there exceptions to the Michigan rule?
Yes. The Michigan rule does not apply to mobile crews that have transportation readily available to nearby toilet facilities, such as a crew that drives between short jobs and can reach a restroom quickly. Where a sanitary sewer is not available, the rule allows chemical toilets, recirculating toilets, combustion toilets or privies, unless local code prohibits them.
When in doubt, put a unit on site. Inspectors, general contractors and union agreements often expect one even for small crews.
What is a good setup for a typical Detroit job?
A typical Detroit residential remodel with 3 to 6 workers needs 1 standard porta potty with weekly service. A commercial build with 30 workers needs 2 units under the Michigan rule, and we recommend 3 plus a handwashing station. A 60-worker site needs 3 units by rule; 4 to 6 units keep lines short at breaks.
See construction porta potty rental for billing and service details.