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Rooftop structures

M

Mark Sigler

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2015 I-codes

I have a proposed A-2 occupancy on the rooftop of a mixed use A-2 (1st floor)/ B (second floor) non-separated occupancy of VB construction which is fully sprinkled. The space as proposed is a compliant application in every aspect with the following issue shown on the plan set which I am struggling with;

The Architect shows the patio furniture on the rooftop complete with tables, chairs, outdoor fire pit, etc.. I'm debating (in my mind and I'm not certain who is winning) the proposed installation of a 10' x 16' cedar trellis, which is post and beam with uncovered 2x rafters, and the umbrellas shown over the tables. Thoughts?
 
A Group A-2 occupancy is not permitted above the second story in Type VB, sprinklered construction.
 
Mark Sigler said:
2015 I-codes

I have a proposed A-2 occupancy on the rooftop of a mixed use A-2 (1st floor)/ B (second floor) non-separated occupancy of VB construction which is fully sprinkled. The space as proposed is a compliant application in every aspect with the following issue shown on the plan set which I am struggling with;

The Architect shows the patio furniture on the rooftop complete with tables, chairs, outdoor fire pit, etc.. I'm debating (in my mind and I'm not certain who is winning) the proposed installation of a 10' x 16' cedar trellis, which is post and beam with uncovered 2x rafters, and the umbrellas shown over the tables. Thoughts?
Click to expand...

[F] 903.2.1.6 Assembly occupancies on roofs. Where an occupied roof has an assembly occupancy with an occupant load exceeding 100 for Group A-2 and 300 for other Group A occupancies, all floors between the occupied roof and the level of exit discharge shall be equipped with an automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2.

The trellises (and pergolas) are not considered roofs that provide weather protection. However the umbrellas could be "fire areas" as Membrane-Covered Frame Structures in Chapter 31.

To further clarify the commentary provides that "There are certain membrane structures that need to be regulated as permanent regardless of how long they are erected. These include membrane structures located on buildings, balconies, decks and similar structures."
"When a membrane structure is placed upon a building or deck, the temporary membrane structure requirements do not provide regulations for key issues associated with permanent structures, such as the means of egress or the limitation of hazardous materials. Therefore, compliance with permanent structure standards is needed. Furthermore, the temporary membrane structure section does not contain requirements on the regulation of the loads that the temporary membrane structures would impose on a structure below.

It is also important to note that the provisions of Section 3102 apply regardless of the use or occupant load of such structures."

I've allowed umbrellas that are readily collapsible to cover only individual tables. A word of caution when considering umbrellas there are so called umbrellas that are actually large movable canopy covering large areas.

Hope this helps.
 
RLGA said:
A Group A-2 occupancy is not permitted above the second story in Type VB, sprinklered construction.
Click to expand...

steveray said:
That was the first thing that popped into my head but did not know for sure....
Click to expand...

To further clarify this new 2015 provision;

“Code users will need to be cautious of how they apply this requirement because it is located within Section 903.2.1 and only applicable to occupied roofs that are used for Group A occupancies. Although most occupied roofs that do have occupant loads reflected in the provisions are generally used for an assembly purpose, if the roof is classified as any other occupancy category, such as a retail space, then the requirement of Section 903.2.1.6 are not applicable. The provisions do allow an NFPA 13R sprinkler system to be provided where the assembly use is located on the roof of a hotel, apartment building or other Group R occupancy.

The application of this new provision should not be extended to other areas of the code. For example, the occupied roof is not considered as a building area, fire area or a story. Therefore, even though an occupied roof is viewed as being assembly occupancy, the limitations of Table 504.4 and many other code provisions would not apply.”

Reference source from the Significant Changes to The International Building Code; First Print, 2014 is not provided in the Code Commentary.
 
Interesting FV, but I am not buying it without a thorough reading of 2015....Where I may agree that the Ch9 requirements to sprinkler everything below may not apply, I don't think they can waive H&A....
 
ADAguy said:
Are you indicating that the roof is accessible? Does it have two accessible means of egress?
Click to expand...
The roof top space per IBC
cda said:
So not the calif version
Click to expand...
Fair enough, I hadn't considered the CBC, because its' all about us "I" coders, isn't it?

Francis-

Greatly appreciate that response and you nailed my concerns/issues.

Others-

I greatly appreciate the responses and inputs and each of your points are valid concerns but ones which are already resolved as indicated in the OP.

Ron-

Regarding the A-2 comment above the second story. While greatly improved over previous editions, I feel the code still fails us regarding occupied roofs for exactly the reason you point out.

My counter to your statement is this; The code doesn't allow an A-2 occupancy on the third story of a VB structure. Occupied roofs do not meet the definition of a story. Nowhere does the code say "above the story". This consideration is what lead to my concern regarding the pergola and umbrellas.

Again, I greatly appreciate all the comment and input.

Respectfully,
 
503.1 General. The building height and area shall not
exceed the limits specified in Table 503 based on the type of
construction as determined by Section 602 and the occupancies
as determined by Section 302 except as modified hereafter.

STORY. That portion of a building included between the
upper surface of a floor and the upper surface of the floor or
roof next above

Right now I am sticking with, it is an A2 occupancy above the second story and not allowed, but you have a better code argument than me at this time.... ;) But I will keep digging or Ron will come up with something. Or this will be the thing I learn today...
 
Steveray - I never said I'm dying on this sword or line of reasoning. Not unlike you the hairs on the back of my neck rise slightly when contemplating this, it just doesn't seem right. It is, however, what I am being presented with and honestly it's pretty compelling. Say what you want about intent and loopholes but I need some place to hang my hat in a court case.

Thanks again,
 
At least the 2015 requires sprinklers, Virginia will not mandate the adoption of 2015 until 2018.

When I became a plan reviewer one of my first occupied roof above a restaurant was 7 yrs. ago under the 2009 edition. 5B construction, non-sprinklered; max. 49 at discharge level and 199 on the roof! The roof area is just under 3,000 sf.

It was a constant battle to have them take down the tent on the roof.

Similarly with more restaurants following suit; now over a dozen occupied roofs without sprinkleres.

We have them above private theater clubs, cafe's, etc.

Welcome to my world & best wishes.
 
Mark Sigler said:
Steveray - I never said I'm dying on this sword or line of reasoning. Not unlike you the hairs on the back of my neck rise slightly when contemplating this, it just doesn't seem right. It is, however, what I am being presented with and honestly it's pretty compelling. Say what you want about intent and loopholes but I need some place to hang my hat in a court case.

Thanks again,
Click to expand...


Yep....I think you might be good, I would dig and dig through commentary and newer code to clarify the intent in a CYA way, I think it was permitguy and I had a big debate over occupied roofs like 8 years ago or so, but we just moved from 2003 based to 2012. And like FV says, I would plaster the CO or whatever to indicate that no "roofs" can be installed...
 
It seems that the benefit sought by the landlord is additional leaseable square footage, tenant beware.
Wonder what BOMA thinks of this and insurance carriers?
Wouldn't this use also impact parapet height if allowed?
 
I had this problem on a Type V apartment project in L.A. We had a building with a rooftop deck to help us meet zoning-code required "common open space". The problem was that we needed about 2200 SF of deck, but an A occupancy was not allowed at that level.
The building official suggested we subdivide the deck into 3 smaller areas (think of them as outdoor "rooms"), each under 750 SF, so that they were too small (individually) to be considered "A" occupancies (303.1.2, item 2). The separation was accomplished via raised planters, and the city allowed 4' max space between the planters for an egress path. (The middle space used the other spaces as intervening "rooms" for exit purposes - 1016.2, item 2.)
One of the decks had a trellis over it. We were not allowed to do a solid roof covering, to avoid creating another story.
We did provide 2 stairs for egress, and an elevator for ADA access. None of these were considered an occupied "story".
The whole thing was designed structurally for corridor exit load / assembly exit live load of 100 PSF. This also worked out pretty well for the weight of our built-in raised planters, swapping increased dead load for reduced live load at those locations.
The city had us complete a code "modification request", which is LA's way of documenting in the file that we had purposefully configured everything to avoid the A occupancy classification, and the conditions were added that we had to maintain the planter positions and not provide any roof coverings.
They did also allow us to have a patio table with an umbrella, but that did not last long: at the roof level, the wind was significant enough to blow it away.
 
Sounds like one we did in Culver City a few years ago, conversion of an old phone company switch building. It was built of reinforced concrete to be blast proof so roof loading was never an issue.
 
Those old phone switch buildings pose all kinds of new development opportunities. All the functions that used to require an entire building full of equipment can now be done in a small rack.
 
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