Access to flat roof on 1 story commercial building

[palikona]

The flat roof I am designing for a 1 story commercial building is 15' above grade. In some places, the roof edge is visible and has a gutter there, and in other locations, there is a parapet that goes up to 16'. For some reason, I thought there was a IBC or OSHA section that allows for roof access to come from a movable ladder (not permanent) and not from a roof hatch. However, now I cannot find those sections anywhere. Does that sound right?
The building is a 10,000 sf footprint, with all of the mechanical equipment hidden behind a screenwall @ the middle portion of the footprint. Would it be a smarter design to provide for a roof hatch within that mechanical yard location, vs a more passive strategy of just saying the owner or workers can access the roof from numerous locations around the building with a movable ladder?

 

[Yankee Chronicler]

IMC 2021:

 

[palikona]

View attachment 13313
IMC 2021:

View attachment 13314

Thank you. So if I read that correctly, I am ok to have the roof accessible by portable ladder since it's 15'?

However, would it be smarter to provide the roof access far from the roof edge, by the mech yard? I'm thinking yes?

 

[Mr. Inspector]

you can always do better than the minimum code requirements.

 

[walker.t]

So if I read that correctly, I am ok to have the roof accessible by portable ladder since it's 15'?

Your understanding is confirmed in the first paragraph of this document:

https://www.iccsafe.org/wp-content/uploads/membership_councils/102516-codenotes.pdf

This is based on the 2015 International Mechanical Code so you’ll want to confirm if any changes have been made to this.

However, would it be smarter to provide the roof access far from the roof edge, by the mech yard? I'm thinking yes?

If your intuition is telling you that it’s better to move the roof access away from the roof edge then that’s probably what you should do.

Over 15 years ago I took an OSHA safety class where the instructor said the largest cause of construction site injuries (maybe they said fatalities?) involved ladders. Here’s an article giving some statistics related to fatalities and injuries involving ladders:

Fatal injuries from ladders down in 2020; nonfatal ladder injuries were essentially unchanged : The Economics Daily: U.S. Bureau of Labor Statistics

In 2020, there were 161 fatal work injuries from which ladders were the primary source. This was a 5.8-percent decline from 2019. Nonfatal ladder injuries resulting in at least one day away from work were essentially unchanged in 2020.

www.bls.gov

In the second chart it says that installation, maintenance, and repair is the biggest group of non-fatal ladder accidents.

I don’t know what kind of OSHA requirements you’ll have, I assume there’s something about attachment points for fall protection.

 

[arwat23]

Thank you. So if I read that correctly, I am ok to have the roof accessible by portable ladder since it's 15'?

However, would it be smarter to provide the roof access far from the roof edge, by the mech yard? I'm thinking yes?

You should be okay at minimum to not install a fixed ladder. I've worked on a few one-story projects recently where we didn't install a built-in ladder.

That said, it's typically far, FAR safer, quicker/more efficient (to access the roof after construction is complete), and just all around better practice to have a built-in ladder if possible. The only reason we didn't install a ladder on those projects was because of the owners refusal due to security concerns. We tried to get them to change their minds...

 

[ICE]

An extension ladder has fatter rungs which are easier on the feet. Climbing an incline is less strenuous than climbing straight up a wall. I prefer an extension ladder even when there is a permanent ladder.