Roof hatches minimum 16 sq. ft.

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Author Message Chris Grimm, CSI, CCS, SCIP Senior Member Username: chris_grimm_ccs_scip Post Number: 494 Registered: 02-2014 Posted on Friday, August 23, 2019 - 05:07 pm:    This is a code requirement and it is not new. Yet designers have been directing me to use much smaller roof hatches for years. Are others seeing a lot of roof hatches in designs that do not meet the code, or am I reading this wrong somehow? [IBC][CBC] 1011.12.2 - Roof Access (Exception for Without an Occupied Roof): Roof hatch or trap door not less than 16 sq. ft. (1.5 sq. m) in area and having a minimum dimension of 2 feet (610 mm). Confirmed below with IBC 2015, 2018; CBC 2016, 2019. For IBC 2012 the reference is 1009.16.1 but the information is the same. I am starting to use Activar: RHDG-5WT, Roof Hatch, Diamond Series 48 inch by 48 inch as a placeholder with a question for the designer until they tell me something different. Rosa Cheney Member Username: rdcaia Post Number: 3 Registered: 07-2018 Posted on Friday, August 23, 2019 - 05:26 pm:    Chris, Maybe half of my Architect clients use the 16 sq. ft. size hatch. The others do once I point out the code reference. I have heard (but don't recall where) that the size is to allow firemen with all their gear to get up through the hatch. We use a 48x48 square for ladder access, and a rectangle for alternating tread stairs. Paul Sweet (Unregistered Guest) Unregistered guest Posted on Saturday, August 24, 2019 - 01:25 pm:    This only applies to buildings 4 stories or higher. You can still use a smaller (30" x 36") hatch on lower roofs. Brian Payne Senior Member Username: brian_payne Post Number: 190 Registered: 01-2014 Posted on Saturday, August 24, 2019 - 02:15 pm:    And since high-rises require a stair to the roof (with exceptions) the larger roof hatch would only apply to buildings 4-7 stories without stair access I believe. Chris Grimm, CSI, CCS, SCIP Senior Member Username: chris_grimm_ccs_scip Post Number: 497 Registered: 02-2014 Posted on Sunday, August 25, 2019 - 10:19 am:    This is a 3-story building and the architect told me to follow that particular code reference. Any tips on how I can show them about it being four+ stories? I did not see that (yet ). Ronald L. Geren, FCSI Lifetime Member, AIA, CCS, CCCA, CSC, SCIP Senior Member Username: specman Post Number: 1563 Registered: 03-2003 Posted on Monday, August 26, 2019 - 11:44 am:    This requirement applies only if a roof hatch is used in lieu of a stair to the roof for buildings with four or more stories. A typical roof access hatch from a mechanical room or any other space is not restricted by this minimum area requirement. Ron Geren, FCSI Lifetime Member, AIA, CCS, CCCA, CSC, SCIP Guest (Unregistered Guest) Unregistered guest Posted on Monday, August 26, 2019 - 11:51 am:    nevermind, Ron Geren took care of it. Guest (Unregistered Guest) Unregistered guest Posted on Monday, August 26, 2019 - 11:50 am:    First, understand that the requirement is for a hatch where there is stairway to the roof (1011.12.2 "Where a stairway is provided...") so if you don't have a stairway, you don't need the 16 sq. ft. hatch. I've seen this come up before, usually by someone who hasn't taken the time to read and understand the code. The reality is, if you have a stair to the roof, you usually get a much larger hatch than 16 sq. ft. (30"-36" x 96" is a common size for service stair access), or you get a door. The code requires a stairway to the roof for buildings 4 or more stories above grade plane unless your roof is steeper than 4:12 (1011.12) and the roof is occupied (refer to language of exception in 1011.12). If you don't have an occupied roof, you don't need a stair*, and you don't need a 16 sq. ft. hatch. If you don't need a stair because your roof is unoccupied, most will simply include a permanent ladder, as allowed per the exception, and an appropriately sized roof hatch. *There is another requirement for stairs to the roof if it is to access elevator equipment (see 1011.12.1). Guest (Unregistered Guest) Unregistered guest Posted on Monday, August 26, 2019 - 12:51 pm:    ha ha, I didn't think my last two comments would get posted. The second was supposed to be the first, and was still a work in progress. It was accidentally submitted before it was finished. I then saw Ron's comment and realized it addressed it better than my post would have. The first was supposed to be the second simply indicating to Colin that he didn't need to bother posting the first. Oh well. Next time I'll try to be more clear, concise, complete, and correct. David G. Axt, CCS, CSI ,SCIP Senior Member Username: david_axt Post Number: 1824 Registered: 03-2002 Posted on Monday, August 26, 2019 - 12:53 pm:    I believe the reason for the large roof access hatch is to allow a firefighter in full gear with oxygen tank on their back to gain access to the roof. David G. Axt, CCS, CSI, SCIP Specifications Consultant Axt Consulting LLC RH (Hank) Sweers II RA CSI CCS Senior Member Username: rhsweers2 Post Number: 20 Registered: 08-2005 Posted on Monday, August 26, 2019 - 12:58 pm:    IBC Paragraph 1011.12 "Stairway to Roof" starts off with "In buildings four or more stories above grade plane . . . " so anything after that is moot with 3 stories or less. The code reference requiring a 16 SF access hatch is in a sub-paragraph of that (1011.12.2's "exception") permitting a hatch in lieu of a penthouse for access to an "unoccupied" roof. Can't hurt to oversize it though - I always spec a guardrail around the opening which isn't clearly required (except possibly by OSHA), but I'd rather have someone else not install it than to not have it specified. Chris Grimm, CSI, CCS, SCIP Senior Member Username: chris_grimm_ccs_scip Post Number: 500 Registered: 02-2014 Posted on Tuesday, August 27, 2019 - 01:10 pm:    Thanks everyone! My client really appreciated being corrected on this. I THOUGHT something didn't seem quite right or many of my other clients would be violation. To help make it easier for them (and me) in the future I have reflected this in my master: [[IBC][CBC][ 1011.12.2] - Roof Access (For buildings having for four or more stories without an occupied roof): Provide roof hatch or trap door not less than 16 sq. ft. (1.5 sq. m) in area and having a minimum dimension of 2 feet (610 mm).] Loretta Sheridan, CSI, CDT, MEng (Unregistered Guest) Unregistered guest Posted on Thursday, March 12, 2020 - 07:35 am:    This is really helpful! I sometimes forget to go BACK to the parent paragraph when you get so far down in the subparagraphs. The EXCEPTION modifies 1011.12.2 which modifies 1011.12: 1011.12 Stairway to roof. In buildings four or more stories above grade plane, one stairway shall extend to the roof surface.... 1011.12.2 Roof access. Where a stairway is provided to a roof, access to the roof shall be provided through a penthouse... EXCEPTION: In buildings without an occupied roof, access to the roof shall be permitted to be a roof hatch or trap door not less than 16 square feet in area and having a minimum dimension of 2 feet. Chad Hanley (Unregistered Guest) Unregistered guest Posted on Tuesday, September 01, 2020 - 11:39 am:    Apologies on digging up an old thread, but what about the roof of the penthouse? Scenario: I have a building 4 or more stories, with a stairway to the main roof and access to that roof through a penthouse. Access to the penthouse roof is an internal ladder with a roof hatch (unoccupied roof). Based on the exception, wouldn't the roof hatch for the penthouse roof need to meet the 16 sf requirement? IBC doesn't really make a distinction between multiple roof levels. Ronald L. Geren, FCSI Lifetime Member, AIA, CCS, CCCA, CSC, SCIP Senior Member Username: specman Post Number: 1585 Registered: 03-2003 Posted on Tuesday, September 01, 2020 - 12:18 pm:    There is no requirement to provide access to the penthouse roof. Ron Geren, FCSI Lifetime Member, AIA, CCS, CCCA, CSC, SCIP Michael Chusid, RA FCSI CCS Senior Member Username: michael_chusid Post Number: 552 Registered: 10-2003 Posted on Tuesday, September 01, 2020 - 03:39 pm:    Ron: Does the area of the penthouse make a difference in your statement, I have seen some very big "penthouses". Chad: why not ladder on exterior of penthouse? You would have one less penetration through roof and probably reduce cost. Michael Chusid, RA FCSI CCS 1-818-219-4937 www.chusid.com www.buildingproduct.guru Marc Chavez Senior Member Username: mchavez Post Number: 603 Registered: 07-2002 Posted on Tuesday, September 01, 2020 - 03:58 pm:    well more than 1/3 of the upper floor makes it a story! so area is important. (shaft wall terminations for example) Ronald L. Geren, FCSI Lifetime Member, AIA, CCS, CCCA, CSC, SCIP Senior Member Username: specman Post Number: 1586 Registered: 03-2003 Posted on Tuesday, September 01, 2020 - 04:28 pm:    As Marc states, a penthouse that exceeds 1/3 the roof area is no longer a penthouse and is now a story, and all the requirements for means of egress would apply (two exits, exit separation, travel distance, etc.). The purpose of the roof access is to allow the fire department to access the inside of the building from the roof. If a roof has a penthouse, it would not make sense for the fire department to access the building through the penthouse roof (in many cases, one would have to exit the penthouse to get to a stairway or hatch making a penthouse roof access even more nonsensical). Further, once on the roof, firefighters can either access the penthouse from the roof (if the fire is there) or into the building through the hatch or stairway. Thus, access to the building's roof is all that is required. Ron Geren, FCSI Lifetime Member, AIA, CCS, CCCA, CSC, SCIP Chad Hanley (Unregistered Guest) Unregistered guest Posted on Tuesday, September 01, 2020 - 04:50 pm:    Michael: Design team wants to avoid a ladder on the exterior of the penthouse, otherwise that would be the simpler solution. Ron: That's a sensible description that I hadn't considered, fire department access into the building from the roof. I was thinking in the other direction, but your description makes more obvious sense. Thanks! Marc Chavez Senior Member Username: mchavez Post Number: 604 Registered: 07-2002 Posted on Tuesday, September 01, 2020 - 05:29 pm:    fun fact, on tall city buildings the City of Seattle requires stairs to the roof. no ladders. The hatch must tie to a stair, have an automatic opener from top and bottom and be heated for snow melt....$$$$$. got to love fire marshals. and as for the ladder maybe the design team could just go . ...removed by internal sensor ....