• Welcome to The Building Code Forum

    Your premier resource for building code knowledge.

    This forum remains free to the public thanks to the generous support of our Sawhorse Members and Corporate Sponsors. Their contributions help keep this community thriving and accessible.

    Want enhanced access to expert discussions and exclusive features? Learn more about the benefits here.

    Ready to upgrade? Log in and upgrade now.

Parapet height question

P

palikona

REGISTERED
Joined
Jan 8, 2022
Messages
85
Location
Colorado
Hi,
I'm designing a new 1 story flat roof dental building that will have a few RTTUs on the roof. They will be accessed from a roof hatch that is located about 9' from the edge of one of the building edges, but more than 10' from all others. My understanding is that you need a parapet when RTUs or access to RTUs/mech roof equipment are within 10' of a building edge. My other understanding is that per IBC, the parapet needs to be 30" min. OHSA states 42" is required for fall protection. Am I ok to design the parapet @ 30"? My worry is that in the future, if someone were to fall, I'd get sued, because of the OSHA mandate of 42". To mitigate that liability, should I design all parapets around the entire building to be 42" high? Or should I show 42" guardrails from the roof hatch, over to the RTUs, and make the parapet 30"? From an aesthetic perspective, the lower the parapet, the better. Thanks for your help.
 
The code does not say you need a parapet for equipment within 10 feet of a roof edge. Section 1015.6 (2018 IBC) requires guards and guards are required to be 42 inches high per Section 1015.3.

Thus, a 30-inch parapet would not comply.
 
Agree with RLGA, IBC 1015.3 Height 42" it would be considered a walking surface from the edge to the roof access at 9ft away, yes?
 
Ok, so what would the guard be? A metal railing that is 42" high? Why do I see 1 story buildings everywhere that have no parapet, RTUs on the roof, and no guardrails?
Thanks.
 
For the OP... Is there a local zoning requirement for the parapet for purposes of screening the RTU's?
 
palikona said:
Ok, so what would the guard be? A metal railing that is 42" high? Why do I see 1 story buildings everywhere that have no parapet, RTUs on the roof, and no guardrails?
Thanks.
Click to expand...
Because they can use a fall arrest harness, yo-yo, and tie-off point in place of a guard. That or the equipment is greater than 10-ft from the roof edge.

1015.6 Mechanical Equipment, Systems and Devices
Guards shall be provided where various components that require service are located within 10 feet (3048 mm) of a roof edge or open side of a walking surface and such edge or open side is located more than 30 inches (762 mm) above the floor, roof or grade below. The guard shall extend not less than 30 inches (762 mm) beyond each end of such components. The guard shall be constructed so as to prevent the passage of a sphere 21 inches (533 mm) in diameter.

Exception: Guards are not required where personal fall arrest anchorage connector devices that comply with ANSI/ASSE Z 359.1 are installed.​
 
A 42-inch parapet qualifies as a guard. There is an exception added in the 2018 IBC that a guard is not required where personal fall protection anchorage devices are installed. Also, if the equipment is located more than 10 feet from the roof edge, no guard is required. If the equipment is surrounded by a screening system, then the screen can be considered a guard if a 21-inch sphere cannot pass through it.
 
RLGA said:
A 42-inch parapet qualifies as a guard. There is an exception added in the 2018 IBC that a guard is not required where personal fall protection anchorage devices are installed. Also, if the equipment is located more than 10 feet from the roof edge, no guard is required. If the equipment is surrounded by a screening system, then the screen can be considered a guard if a 21-inch sphere cannot pass through it.
Click to expand...
If the equipment is all well inboard of the edge of the roof (IE 20’) but the roof hatch is 9’ from one roof edge (but more than 12’ from others), would I be smart to have a 42” parapet to comply with code? It seems overkill to me and it seems I could have a 42” guard around the roof hatch and that’s it?
 
mtlogcabin said:
Or you can install one of these and make sure your gate is the farthest point from the edge of the roof
View attachment 8775
Click to expand...
This makes sense to me. The 9’ from the roof edge to the hatch would be on the other side (hinge side) of this hatch in the pic. As the worker comes up a ladder, he/she would exit the hatch inboard of 10’ from any roof edge.
Therefore, it seems I’d be ok with a lower parapet?
 
California mechanical code:

304.3.1.1 Access Type. The inside means of access shall be a permanent, or foldaway inside stairway or ladder, terminating in an enclosure, scuttle, or trap door. Such scuttles or trap doors shall be not less than 22 inches by 24 inches in size, shall open easily and safely under all conditions, especially snow; and shall be constructed so as to permit access from the roof side unless deliberately locked on the inside.
» 88A. [NFPA 54:9.1.11.1]
Not less than 6 feet of clearance shall be between the access opening and the edge of the roof or similar hazard or rigidly fixed rails or guards not less than 42 inches in height shall be provided on the exposed side. Where parapets or other building structures are utilized in lieu of guards or rails, they shall be not less than 42 inches in height.

Apparently Colorado code has 10’ instead of 6’.
 
Last edited:
You can always install railing(s) which extend to 42" high and are mounted on the top or back of the parapet where equipment is within 10 ft of the outside face of the parapet.

As far as I know the 30" parapet is only required for a fire wall when you don't meet one of the exceptions in IBC 706.6.
 
Tim Mailloux said:
I specify these collapsible safety rails on many of my projects. When not in use the fold down out of sight and are not an eye sore.
Click to expand...
I seen several places where removable or collapsible rails like that are not accepted by local authorities at meeting. Code requirements. I noticed on the website that it was acceptable to OSHA standards according to an engineering firm analysis. That's not the same as acceptance by OSHA and I can see where it could be a issue.
 
davecarlson98 said:
Hi Tim, that is an interesting solution....Does the company warrant that the system will meet code requirements like California Building Code 1015.6?
Click to expand...
Dave

as far as I am aware they meet all the code requirement for guardrails here in CT, and I have frequently use these on state projects under the preview of our State Building Official and State Chief Architect it they have never been an issue.
 
I had previously tried a similar system on a rooftop, where I had placed the guardrails close to the edge of the roof. The plan checker pointed out that in order to set up the collapsible guardrail, a worker needs to walk within 10' of the building edge, without the guardrail in place. He made us add tie back fall protection anchors on the roof so that a worker could first tie onto those before setting up the guardrails.

1670532467349.png
 
We have seen these on a couple of projects. We ask for an additional standoff to keep the guard off the roof deck about 12" when in the down position. They don't work well when frozen to the roof or buried under the frozen snow.
 
You must log in or register to reply here.
Back
Top