• 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.

Minimum parapet height for flat roof with no mech?

gnarkill283

REGISTERED
Joined
Nov 15, 2017
Messages
117
Location
New York
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
 
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.
 
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?
 
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.
 
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.
 
1504.8 is now Impact Resistance (for foot traffic on low-slope roofs).

1504.9 is the parapet height table.


This is the unmodified IBC; several states will probably modify it to keep banning aggregate.
 
I think that OSHA only requires fall protection when within 6 ft. of the roof edge, vs. 10 ft. for the IBC guard requirement.
 
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?
 
Wish I could edit posts. The first sentence in my previous post is confusing - There ARE drains within 10' of the edge
 
Back
Top