The roof of the MTA’s largest bus depot is filled with “excessive” trip hazards, holes and puddles, the state Department of Labor has charged in official documents.

DOL investigators last week flagged the Michael J. Quill Bus Depot in Midtown Manhattan with four employee safety violations — including one for unsanitary and disorderly conditions on the building’s roof.

“There are excessive amounts of trips and falls hazards due to the roofs [sic] floor having large amounts of cracks & potholes,” officials wrote in a safety violation notice obtained by The Post.

“Employees are exposed to serious physical harm due to slip, trip and fall hazards caused by the floor cracks, holes/potholes and uneven surfaces throughout the entire roof.”

Other DOL violations issued last week included ones for the MTA’s failure to post publicly the city-approved weight loads for the building and to enforce personal protective equipment and helmet rules for workers.

State officials referred the structural concerns to the city’s Department of Buildings.

“There were some holes in certain areas of the roof where the rebar was visible,” inspectors wrote. “The roof was observed to be uneven with water accumulating in certain areas.”

Renovations on the deteriorating roof are supposed to happen next year, The Post previously reported. The building remains safe to occupy in the meantime, officials said.

As The Post earlier reported, the repair work was two years delayed despite being flagged by the DOL earlier this year as potentially compromised.

“The MTA takes safety very seriously and is fully cooperating with the Department of Labor in remediating concerns raised in the filings right away,” MTA spokesman Aaron Donovan said in a statement Sunday.

“MTA engineers look forward to further addressing conditions noted in the report relative to cracks, potholes and ponding, while also replacing a deck, curbs, and expansion joints.”

The roof of the depot holds up to 120 buses at any given time. MTA officials are struggling to find space to make up for the lost storage capacity during the repair work scheduled for 2023.

Officials are considering streets and lots as far away as Harlem, The Post reported in July – including nearby Javits Center, curbside spots on 40th and 41st streets, the Sanitation Department’s garage at 57th Street and surface lots at 30th Street and 126th Street.

Internal MTA documents indicate the bus depot closure could last anywhere from three weeks to four months.