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defining fire area

B

BSSTG

Gold Member
Joined
Nov 30, 2009
Messages
729
Location
Seadrift, Tx.
Greetings all,

fire area is defined per 09 IBC

FIRE AREA. The aggregate floor area enclosed and bounded by fire walls, fire barriers, exterior walls or horizontal assemblies of a building. Areas of the building not provided with surrounding walls shall be included in the fire area if such areas are included within the horizontal projection of the roof or floor next above.

Will be looking at a new A2. Interior of bldg has occ load of 94. Patio area increases load to well over 100 thereby kicking in sprinkle requirements. Patio is open air with ornanmental fence including plenty of ingress/egress. Roof of the patio is a continuation of the bldg structure. I know this same bldg has been built in 2 other sizeable towns and FM let them go with occ load which excludes the patio area thereby getting by without sprinklers. From a practical standpoint, I can see their point. However, the occ load under one roof is realistically propably 150-175. Seems to me the Code is clear that the bldg should be sprinkled.

So what say you folks? BTW, I stopped in one yesterday to check it out and try a burger which is supposedly really good. I wasn't impressed with the burger but the place was nice. The occ load was posted as 94 just inside the main entrance.

thanksabunch

BSSTG
 
What is the sq. ftg of the building?

903.2.1.2 Group A-2. An automatic sprinkler system shall be provided for Group A-2 occupancies where one of the following conditions exists:

1. The fire area exceeds 5,000 square feet;

2. Thefire area has an occupant load of 100 or more;

or

3. Thefire area is located on a floor other than a level of exit discharge serving such occupancies.

4. The structure exceeds 5,000 square feet, contains more than one fire area containing a Group A-2 occupancy, and is separated into two or more buildings by fire walls of less than four hour fire resistance rating without openings.
 
From the Fire Area definition, the patio Area is not a fire area, unless bounded by Walls. A ornamental fence fence is not a wall, and you stated the diners has egress through the fence.
 
mark handler said:
From the Fire Area definition, the patio Area is not a fire area, unless bounded by Walls. A ornamental fence fence is not a wall, and you stated the diners has egress through the fence.
Click to expand...
I agree from the definition. However, it's the last part of the def that I think is squirrely about the roof structure. The entire seating area is under 1 roof, although a lot of it is open patio.

definition 2nd sentence "Areas of the building not provided with surrounding walls shall be included in the fire area if such areas are included within the horizontal projection of the roof or floor next above."

BSSTG
 
Does any of the patio exit back into the building?

If not is the patio have code complying exits?? Sounds like the patio needs two exits
 
Some interpret that you have 2 different fire areas. The enclosed area and the unenclosed roof area. You have an exterior wall separating the fire areas. If you want no doubts about having two different fire areas require the exterior wall to meet the 2 hour fire barrier requirement and then no sprinklers are required.
 
Exterior wall is where the fire area starts and stops again, regardless of whether or not the wall is rated. Rated wall is a bonus though, but not needed. As long as there are exits off the patio through the fence. FWIW
 
Glennman CBO said:
Exterior wall is where the fire area starts and stops again, regardless of whether or not the wall is rated. Rated wall is a bonus though, but not needed. As long as there are exits off the patio through the fence. FWIW
Click to expand...
FIRE AREA. The aggregate floor area enclosed and bounded by fire walls, fire barriers, exterior walls or horizontal assemblies of a building. Areas of the building not provided with surrounding walls shall be included in the fire area if such areas are included within the horizontal projection of the roof or floor next above.

I would interpret the word included to mean that the patio area would be added to the fire area of the building, not make up it's own area. I often find myself looking at plans in situations like this where I feel the code is overly restrictive from a strict reading. Most of the time if I discuss this with the developer they can provide documentation for me to see it their way. They get what they want and they keep the liability because there is documentation of their argument.
 
The fire area definition in the 2009 edition includes roofs that are not rated which were a condition of the 2006 definition for sprinklers.

Have you notice the big box supply stores outdoor covered areas are sprinklered.



Francis
 
If the exterior wall extends to the roof deck then I believe the intent of the code is meant about the exterior wall creating a fire area regardless of the walls fire rating. However if the roof trusses extend over the exterior wall to provide the covered area then no you do not have separated fire areas created by the exterior wall and a fire barrier would be required to create spate fire areas with an OL of less than 100 in each one in order to avoid sprinklers and be code compliant.
 
: = : - :

BSSTG,

One other wrench to throw in to your mix is, the calculated

Occ. Load may not be a real world application.

Ex: Last year we had a Bird Fil-A Restaurant built in our AHJ.

The calculated Occ. Load was over 100, so they sprinkled it

without batting an eye........On opening day, they had

standing room only, with every single seat filled [ 200+ ].

They had an outdoor dining [ patio ] area, which DID

contribute to the overall Occ. Load and the plbg. fixtures

count.....They added additional plbg. fixtures because of

their anticipated Occ. Loads, and continue to do very

well with their business........FWIW, ...they are still not

open on Sundays either !......This particular restaurant

located right next to an interstate highway, so their

customer / traffic counts were & still are high !

: - : = :

 
IN a nutshell, the new definition is designed to include nay area under a common roof line........ the exterior walls are moot at this point....

a sprinkler system in this application is for property protection with life safety feature added.... (NFPA 13) . Sprinkler spray pattern tends to umbrella in design...

NFPA 13R is a occupant (life) safety sprinkler system with the added feature of some property protection may be achieved.... spray pattern is designed to spray water within the top 30 inches of the wall to prevent flash over and create a tenable environment for 10 minute in the room of fire origin.
 
Francis Vineyard said:
The fire area definition in the 2009 edition includes roofs that are not rated which were a condition of the 2006 definition for sprinklers.Have you notice the big box supply stores outdoor covered areas are sprinklered.



Francis
Click to expand...
Greetings again,

Yes I have noticed that on the Home Depot's etc. Sprinklers under the canvas in the gardening section. Interesting too.

Well, drawings for this have not come in thus far. However we did have a predevelopment meeting with these folks awhile back and I asked about sprinklers and got the reply of the occ load at 94 from the architect. I drive by one of the existing restaurants from time to time and had noticed it was actually a pretty large structure so that's when I decided to drop in and check it out. That's what has prompted my thoughts on this. It will interesting if and when drawings come in.

I feel that the intent of the Code is to have this all sprinklered without a doubt. And it's funny too. We have an Applebee's coming in that's small and they sprinkler them anyway. Smart.

BSSTG
 
IN a nutshell, the new definition is designed to include nay area under a common roof line........ the exterior walls are moot at this point....
Click to expand...
Then exterior wall should be removed from the definition. The commentary is just another opinion.
 
Agreed mtlogcabin. If the fire area continues through the exterior wall because of the continuation of the roof, then the exterior wall is a mute point. One could say its the same fire area due to the roof, another could say its not the same fire area because of the wall. Typical code language. Why am I so surprised?
 
What if said patio had no exiting from the patio, except back through the building???

And even if the patio had no roof line over it
 
The key word is projection; a free standing roof not attached but against the exterior wall would not be an extension of a fire area.

However outdoor area occupant load and means of egress has to be considered in the calculation if through the building but is not included for the sprinkler.

Francis
 
Last edited by a moderator:
The occupants entering back through a building do not add to the occupant load for the room they exit through they only contribute to the exit requirements not the fire area OL requirements

cda said:
What if said patio had no exiting from the patio, except back through the building???And even if the patio had no roof line over it
Click to expand...
1004.8 Outdoor areas.Yards, patios, courts and similar outdoor areas accessible to and usable by the building occupants shall be provided with means of egress as required by this chapter. The occupant load of such outdoor areas shall be assigned by the building official in accordance with the anticipated use. Where outdoor areas are to be used by persons in addition to the occupants of the building, and the path of egress travel from the outdoor areas passes through the building, means of egress requirements for the building shall be based on the sum of the occupant loads of the building plus the outdoor areas. th

 
Do you add the occupants that exit from space A through a horizontal exit to the occupant load of space B for fixture counts and ventilation requirements etc.? If not then why would you add the two OL's to require sprinklers? Or do you just make sure the exit widths are correct for the additional OL?
 
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