# Minimum parapet height for flat roof with no mech?



## gnarkill283 (Apr 21, 2021)

I've got a 5 story building with the first 4 stories of commercial and the top floor and roof top belongs to penthouse residential suite. We have flat roofs on the bulkheads of the stair/elevator/mech rooms - what's the lowest height for the parapet around these flat roofs if there is no mechanical equipment just drains (so its not technically accessible right?)? 8" is what we once designed in the Bahamas - hoping its the same for Florida or in the IBC but can't find the info anywhere. Thanks


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## redeyedfly (Apr 21, 2021)

IBC 705.11  The IBC has an index.

Parapet requirements do not depend on any of the things you listed.  You may use a parapet as a guardrail to satisfy mechanical code and OSHA requirements for rooftop units but that is different from the parapet requirements for fire.


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## gnarkill283 (Apr 21, 2021)

redeyedfly said:


> IBC 705.11  The IBC has an index.
> 
> Parapet requirements do not depend on any of the things you listed.  You may use a parapet as a guardrail to satisfy mechanical code and OSHA requirements for rooftop units but that is different from the parapet requirements for fire.


The parapet does not need to be fire rated as its outside of any fire separation distance requirement so therefore the roof could meet the wall flush (so a right angle) if an architect wanted to design it that way then right?


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## steveray (Apr 21, 2021)

Correct....if it is not a firewall or some other special thing, no parapet required...


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## Paul Sweet (Apr 23, 2021)

According to a code update article in the April 2021 NRCA Professional Roofing magazine, the 2021 IBC has amended section 1504.9 to require parapets on aggregate-surfaced roofs.  The parapet height varies from 2" (gravel stop only) to 56"(!) depending on wind speed, exposure, and mean roof height.  

Aggregate-surfaced roofs were previously banned in hurricane-prone areas, and in non-hurricane areas depending on wind speed, exposure, and mean roof height.


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## steveray (Apr 23, 2021)

They might still be unless 2021 is brining it back...?

1504.8 Aggregate. Aggregate used as surfacing for roof coverings
and aggregate, gravel or stone used as ballast shall not
be used on the roof of a building located in a hurricane-prone
region as defined in Section 202, or on any other building
with a mean roof height exceeding that permitted by Table
1504.8 based on the exposure category and basic wind speed
at the site.


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## Paul Sweet (Apr 24, 2021)

1504.8 is now Impact Resistance (for foot traffic on low-slope roofs).

1504.9 is the parapet height table.






						2021 INTERNATIONAL BUILDING CODE (IBC) | ICC DIGITAL CODES
					

ICC Digital Codes is the largest provider of model codes, custom codes and standards used worldwide to construct safe, sustainable, affordable and resilient structures.




					codes.iccsafe.org
				




This is the unmodified IBC;  several states will probably modify it to keep banning aggregate.


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## ADAguy (Apr 26, 2021)

Caution, roof drains require periodic cleaning, must provide tie-offs if no guards.


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## redeyedfly (Apr 27, 2021)

ADAguy said:


> Caution, roof drains require periodic cleaning, must provide tie-offs if no guards.


Only if they're within 10' of the roof edge.


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## ADAguy (Apr 28, 2021)

Depends on fall height on a windy day? best practice to still provide them.


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## redeyedfly (Apr 28, 2021)

ADAguy said:


> Depends on fall height on a windy day? best practice to still provide them.


Yeah they're not free.  No owner will pay for guardrails on a roof that aren't code minimum.  No revenue from guardrails.


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## ADAguy (Apr 29, 2021)

Until they are sued.


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## redeyedfly (Apr 29, 2021)

ADAguy said:


> Until they are sued.


You don't get sued for following OSHA.  There are many risks in owning a building, this is not one of them.


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## Paul Sweet (Apr 30, 2021)

I think that OSHA only requires fall protection when within 6 ft. of the roof edge, vs. 10 ft. for the IBC guard requirement.


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## redeyedfly (Apr 30, 2021)

Paul Sweet said:


> I think that OSHA only requires fall protection when within 6 ft. of the roof edge, vs. 10 ft. for the IBC guard requirement.


I thought 6' is the allowable drop before a tie off or guardrail is required instead of 30" in IBC.  But I'm too lazy to look it up.


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## ADAguy (Apr 30, 2021)

As I said, it comes down to risk management, little cost to provide tie-offs vs major claim payouts.


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## redeyedfly (Apr 30, 2021)

ADAguy said:


> As I said, it comes down to risk management, little cost to provide tie-offs vs major claim payouts.


That’s the thing, tie offs and guardrails are not little cost.


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## gnarkill283 (Jun 4, 2021)

These bulkhead roofs do not need fire rated parapets and have drains within 10' of the edge. They are currently designed without access (meaning no permanent ladder/hatch going up to them). If someone has to clear out a drain, they will have to use a ladder. What do I need to provide? Also is the 10' rule based on the idea that maintenance personnel gain access to the roof through a hatch?


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## gnarkill283 (Jun 4, 2021)

Wish I could edit posts. The first sentence in my previous post is confusing - There ARE drains within 10' of the edge


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