Classification as an E

[Sifu]

I have a school addition, separated from the existing school by a fire wall, that is mostly vocational, about 90% of the area is diesel, welding, and agricultural shop. Due to the size of these uses, they would not be considered incidental to the E, in fact they are the reason for the E. If it is all an E, and none are incidental, then would 509 apply? I ask because they are providing smoke construction as required by 509.4.2, but falling short with door hardware and smoke dampers. If it isn't required to comply with 509 I wonder if it matters. 2021 IBC.

 

[classicT]

Interesting question...

Perhaps, this may not be classified as a Group E. Incidental uses are after all limited to 10% of the building area for that story. Given that the proposed addition is almost entirely uses that fall under the incidental use descriptions of Table 509.1, an issue with 509.3 appears to exist. I'd note the definition of building area, as the definition specifically addresses bounding by a fire wall.

While I have not run across this issue myself, given the cursory review I just made, I'd be inclined to say that the proposed vocational areas are not incidental uses given they exceed the area limitation of 509.3. As such, they would be individually classified per Ch. 3, resulting in a mixed use building (Group E, S-1, and maybe F-1).

2021 IBC​

509.3 Area Limitations​

Incidental uses shall not occupy more than 10 percent of the building area of the story in which they are located.

[BG] 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.

 

[Tim Mailloux]

I have a school addition, separated from the existing school by a fire wall, that is mostly vocational, about 90% of the area is diesel, welding, and agricultural shop. Due to the size of these uses, they would not be considered incidental to the E, in fact they are the reason for the E. If it is all an E, and none are incidental, then would 509 apply? I ask because they are providing smoke construction as required by 509.4.2, but falling short with door hardware and smoke dampers. If it isn't required to comply with 509 I wonder if it matters. 2021 IBC.

I don't see why those vocational space (aka classrooms or labs) would not be considered part of the E occupancy.


305.1 Educational Group E. Educational Group E occupancy includes, among others, the use of a building or structure, or a portion thereof, by six or more persons at any one time for educational purposes through the 12th grade.

 

[steveray]

As such, they would be individually classified per Ch. 3, resulting in a mixed use building (Group E, S-1, and maybe F-1).

Yep....I would go about it backwards...The uses are already declared/ accounted for, therefore not incidental...But same result

 

[Sifu]

I followed the path T did, and wound up conflicted. They are certainly used for education, and would not be incidental to the E, because they are the E and they are larger than 10%. I don't think I have an issue with E, just whether they would be subject to section 509....now extend that question to an H occupancy. If I have, for example, an H2 woodshop in a high school, 307.1 & 305.1 both mandate a classification, and it would seem the uses may fit both. This project has woodworking in the ag shop, and two separate welding shops, one of which opens to the woodworking shop! I will request a hazard assessment but if they come back with a high enough concentration of dust to warrant an H2, we could have conflicting mandates. To my surprise, they are not providing a dust collection for the wood-working so hopefully it has been assessed and deemed to be of a low enough concentration, otherwise I assume they would have provided one to lower it. They are providing exhaust and dust collection for the hot-work rooms. Probably a moot point; if the dust was heavy enough they would provide collection to keep it from being an H2, but still curious.

 

[Sifu]

Let me expand with one more observation, as I have not encountered this. One of the welding shops is accessed ONLY through the shop with the wood working through a double door (hardware and operation is unknown as of now). That welding shop has an independent exhaust interconnected with the larger hot work room on the other side, including a hood for a future plasma table at 3200cfm, which I presume would tend to suck the combustible dust into the room, and up the intakes. I am not a fire expert by any stretch, but that seems, well..., stupid.

 

[classicT]

@Sifu, I agree with you. While the intent of these vocational spaces is to provide education, I would assess that the function of these spaces represents a higher level of hazard and risk to the building occupants. Because of this, I would say that classifying them without regard to the educational component may be the correct thing to do.

2021 IBC 301.1 General​

The provisions of this chapter shall control the classification of all buildings and structures as to occupancy and use. Different classifications of occupancy and use represent varying levels of hazard and risk to building occupants and adjacent properties.

 

[Sifu]

The building works as non-separated for everything but the H2, and I'll eat my shorts if that is what it ends up being. Using E and incidental is actually more restrictive because of the smoke walls, door operation and smoke dampers.

 

[Yankee Chronicler]

Yep....I would go about it backwards...The uses are already declared/ accounted for, therefore not incidental...But same result

I disagree. Section 509 applies because it says it applies. It doesn't say to NOT classify the shops as Use Group E, but it recognizes the potentially higher fire hazard created by the subjects being taught and therefore requires additional safety features.

 

[Yankee Chronicler]

The building works as non-separated for everything but the H2, and I'll eat my shorts if that is what it ends up being. Using E and incidental is actually more restrictive because of the smoke walls, door operation and smoke dampers.

That's the point.

 

[steveray]

Yep....E and F2 for metal fabrication requires no separation (assuming sprinklers):


So again....not "incidental use" declared use, mixed, non-separated.......

 

[princeofpen]

As this is a separate building 509 does not apply and being that the addition is separated with a fire wall, however, mechanicals between the 2 buildings would need smoke /fire dampers not just fire dampers.
As far as uses it would still be an "E" until they cross any threshold for combustible/flammable etc and I wouldn't approve a woodworking shop without dust collection as they wouldn't be able to provide a level of dust produced data that would make any sense other than "this is what we've always done". Your point of dust traveling from woodworking to metal fab area is completely correct and hazardous. The design of egress travel from woodworking to metal shop would be a no go in my opinion as arcs and sparks do not match wood dust/lumber unless self closing doors etc would be added.