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Area separation at a service canopy - A fire wall with no walls?

N

nealderidder

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Joined
Dec 7, 2010
Messages
420
Location
Sacramento, CA
I think I attached an image to this post showing a building section... The grey lines show existing buildings. The darker lines a proposed canopy. This is a car dealership and this canopy is a covered drive-thru where you check in for service. The small enclosed area in the center is a conditioned space for the really hot times (think toll-booth). The canopy is free standing, unenclosed, and has a footprint of around 8,600 SF.

This canopy "connects" a 45,000 SF building to a 10,000 SF building resulting in a building which puts me over my allowable floor area. Dang!

A few questions come to mind:

1. Should a service canopy be considered building area? There are no surrounding exterior walls (see AREA, BUILDING definition) and doesn't the rest of that definition imply that there are walls SOMEWHERE in order to be defined as Building Area?

2. Assuming I can't convince you that this 8,600 SF shouldn't be called "Building Area" how does one go about building a Fire Wall between a canopy and an existing building? Build a free-standing wall next to the existing wall just for the purpose of having a wall?

I bet some of you have run into this before. Any words of wisdom?

Thanks,
Neal









2lb2e84.jpg
 
AREA, BUILDING. The area included within surrounding exterior walls (or exterior walls and fire walls) exclusive of vent shafts and courts. Areas of the building not provided with surrounding walls shall be included in the building area if such areas are included within the horizontal projection of the roof or floor above.

Do the existing exterior walls meet any kind of fire rating?

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.

Sprinkler increase maybe?
 
The existing wall on the left was called out as a 2 hr area separation wall on the original drawings. That hasn't been verified.

I'm already maxed out with sprinkler and frontage increases...
 
nealderidder said:
The existing wall on the left was called out as a 2 hr area separation wall on the original drawings. That hasn't been verified.

I'm already maxed out with sprinkler and frontage increases...
Click to expand...


Any openings in the two hour wall??
 
nealderidder said:
The existing wall on the left was called out as a 2 hr area separation wall on the original drawings. That hasn't been verified.

I'm already maxed out with sprinkler and frontage increases...
Click to expand...

The canopy will reduce the original frontage increase number on both buildings.
Do you have a plan view?
Does this help?

Table 706.4 footnote "a"
in Type II or V construction, walls shall be permitted to have a 2-hour fire-resistance rating.
 
mtlogcabin said:
The canopy will reduce the original frontage increase number on both buildings.
Do you have a plan view?
Does this help?

Table 706.4 footnote "a"
in Type II or V construction, walls shall be permitted to have a 2-hour fire-resistance rating.
Click to expand...


I think we're veering of course here. Regardless of whether it's a 2 hr or 3 hr wall, the question is - how do you build a fire wall against an unenclosed canopy?
 
nealderidder said:
I think we're veering of course here. Regardless of whether it's a 2 hr or 3 hr wall, the question is - how do you build a fire wall against an unenclosed canopy?
Click to expand...


not an engineer or the greatest IBC person

But it seems like you pick one of the buildings that is against the canopy, and built a two hour wall, so you have

one building, the canopy, the two hour wall, the other building.


ORRR, you ask the ahj, if I have one foot separation, or whatever distance THE AHJ will accept,,, on either side from the building am I legal???

ORRR, provide the separation on both sides, so it is free standing.
 
Could the existing exterior walls of the 2 enclosed buildings be considered as fire walls?
Is the Existing Building Code adopted and a viable option? (Not sure what Colorado has in place...)
 
If the existing exterior walls do not work as firewalls, you would need to make (at least one of) them.....No other way out of H&A....And at the 10,000ft building you would need a fire barrier as well or you will be sprinklering the canopy for sure...If you were not already intending...
 
"Build a free-standing wall next to the existing wall just for the purpose of having a wall?"

It's not just a wall, it is code and creates a separate building...
 
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nealderidder said:
I think I attached an image to this post showing a building section... The grey lines show existing buildings. The darker lines a proposed canopy. This is a car dealership and this canopy is a covered drive-thru where you check in for service. The small enclosed area in the center is a conditioned space for the really hot times (think toll-booth). The canopy is free standing, unenclosed, and has a footprint of around 8,600 SF.

This canopy "connects" a 45,000 SF building to a 10,000 SF building resulting in a building which puts me over my allowable floor area. Dang!

A few questions come to mind:

1. Should a service canopy be considered building area? There are no surrounding exterior walls (see AREA, BUILDING definition) and doesn't the rest of that definition imply that there are walls SOMEWHERE in order to be defined as Building Area?

2. Assuming I can't convince you that this 8,600 SF shouldn't be called "Building Area" how does one go about building a Fire Wall between a canopy and an existing building? Build a free-standing wall next to the existing wall just for the purpose of having a wall?

I bet some of you have run into this before. Any words of wisdom?

Thanks,
Neal




So




2lb2e84.jpg
Click to expand...



So related

Are the existing buildings sprinkled???
 
nealderidder said:
I'm already maxed out with sprinkler and frontage increases...
Click to expand...

mtlogcabin said:
The canopy will reduce the original frontage increase number on both buildings.
Click to expand...

To reiterate the fire wall will reduced the frontal increase or open area of the existing building. Currently building area and fire area definitions have the same language.

Might see if AHJ will consider code modification with a non-combustible 4-hr. fire wall.

Fire walls can be constructed in many different ways and is left up to the designer to show how this performance-based requirement is being met.
 
Last edited:
Thank you all for weighing in. Some clarification - the existing buildings are sprinkled and the new canopy will be sprinkled as well. The canopy and the existing building to the right in the section are building "B" the existing building to the left of the canopy is building "A". The fire wall wants to be between the new canopy and the building to the left - no need for another fire wall on the right.

I've passed on this question to the local building official. I'm going to try selling the following plan:

Upgrade the existing wall (on the left of the canopy) from 2 hr to 3 hr AND provide a 3 hr assembly at the parapet/fascia of the new canopy where it faces the building on the left. I wouldn't be surprised if he might also want us to provide a rated roof/ceiling assembly for the entire canopy. Everything is non-combustible and sprinkled so I'm hoping he will feel comfortable allowing us to do something less than building a free-standing 3 hr wall.

I'll post back when I get some resolution.

Regards,
Neal
 
Or go a little higher and extend the roof out over the buildings,,

So nothing is connected
 
nealderidder said:
I think we're veering of course here. Regardless of whether it's a 2 hr or 3 hr wall, the question is - how do you build a fire wall against an unenclosed canopy?
Click to expand...
As others have stated
Use the existing building wall.
The footnote in the table only requires 2 hours for Type II or Type V construction. Not hard to do
 
What is the most restrictive construction type of the three buildings? What occupancy groups are within all three buildings? Are any portions of the buildings separated by fire barriers?

Answers to these questions (and others, depending on the responses to the above) may open up other avenues of compliance other than fire walls.
 
RLGA said:
What is the most restrictive construction type of the three buildings? What occupancy groups are within all three buildings? Are any portions of the buildings separated by fire barriers?

Answers to these questions (and others, depending on the responses to the above) may open up other avenues of compliance other than fire walls.
Click to expand...

Thinking unlimited area?
 
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