NFPA Running Exhaust through Firewall

I am trying to open a business in Jersey City NJ. I am facing very big challenges running duct work for my commercial oven (for baking) and for my TYPE II hood. The problem is the building is six stories high. There is no chase and nowhere else but to vent but through the Garage next to me. After reading the NFPA it states that I cannot Duct through Firewall. The issue is that I have a clean air return vent going out the front which elminates my chances of going out the front of my store. The only solution is to penetrate through the wall to the garage and vent outsite. Can it be done? Also the lady behind the garage is not allowing me on her property to do the work. She thinks that my vents will affect her customers when they have outdoor seating. the vents will be 20 feet from the ground and its only blowing air.


Has the local building official or acting officer not offered any options or resolutions? Because they should. If not, contact someone who can provide you with a design plan for submittal to the building dept, who can approve it from there.

The fire inspector came today to inspect my sprinkler basically said I have to follow NFPA 96 code and it states I can’t duct through fire wall. My architect and engineer are the ones who put me into this predicament.

Have to love that. That’s the difference between designing and building. A good number of designers never see their application, theories, and designs in action. The next step is to contact the building official and tell him you want to work with him. You might be surprised, but they will want to work with you too. They aren’t in the business of keeping you out of business, they just want to make sure you’re not endangering anyone.

You have to understand that none of us could possibly give you a remedy and a green light. We can just tell you when you did something wrong;-).

It can be done easily and still comply with NFPA. Call my cell tonight at (720) 272-8578 and I’ll explain. I’m holding NFPA 86 in my hands.

How when NFPA 96 (1998 edition) states…
4-1.1 Ducts shall not pass through fire walls or fire partitions.

(FYI: 2008 edition gives similar info…)

[size=2]So, with that stated (and applying NFPA 96 as opposed to 86), how do you legitimately comply while penetrating a fire wall or partition? Inquiring minds would like to know.[/size]

Yes Chris, that was the point with my previous posts in this thread. I think someone went a little overboard. I’m a little annoyed.


If you can’t raise the bridge, lower the water.

Run the pipe through the garage to the outside like you wanted to.

Build a drywalled chase around ducts.

The space inside the chase now becomes (for firewall purposes) part of the bakery, not the garage any longer.

Garage firewall back intact.

Don’t have either of the NFPA standards but what about the use of smoke/heat actuated UL approved fire dampers where the duct passes through the fire barrier?

Nick, bottom line is I don’t believe it is our call, position, or scope to instruct someone how to penetrate a fire wall, especially with out being there in person. In my opinion, if this person had contacted the appropriate people, he would have this information. Instead, he contacted the “neighbor lady” to see if he could use her property. The only inspection information he states is “The fire inspector came today to inspect my sprinkler”. Sprinkler. Period.

With a design plan from a “design specialist”, filed with the appropriate building officials, he would have all the info he needs. And that is the type of process we should be endorsing.

Sounds to me like this is the exact type of work we have to look out for when we are in the field, and you are encouraging it. From what I gather, you haven’t inspected in a long time, and having access to code books does not qualify you dole out such information. I have a book on psychology at my house, but I do not invite people to call me for help with the subject.

Design specialist? This one wouldn’t even warrant me scribbling on a napkin. If I were there I could create a supply list in my head in 30 seconds, and it would be 100% NFPA compliant.

not to be arguementative…

  1. NFPA defines shall as… Shall**:** Indicates a mandatory requirement. Therefore when it states “shall not pass through fire walls” means that it is not optional or recommended.

  2. You have still penetrated the fire wall, which in regards to NFPA 96 (1998 edition), states:

Fire Barrier Wall:
A wall assembly complying with the requirements of NFPA 221, *Standard for Fire Walls and Fire Barrier **Walls, *having a fire resistance rating of 4 hours.

Unless I am incorrect, with fire walls which separates two portions of a building (non-kitchen duct related), any penetrations would have to be filled/sealed with material capable of maintaining the fire resistance of the fire barrier or an approved device designed for that purpose.

However in the case of a kitchen duct, the code specifically states that ducts shall not pass through the fire wall and is not followed up with any exceptions. Therefore, it could be implied that the idea is to not reduce the integrity of the fire wall by penetrating it with the duct and to prevent the spread to fire to the opposite area of the fire wall. Additionally, in the case where a kitchen duct has penetrated a fire wall, that would allow grease to potentially accumulate in the duct on the opposite side of the fire wall. Thus in the event of a duct fire, by maintaining the duct on the kitchen side of the fire wall, you would (barring any penetrations in the wall) keep the fire compartmented to that area. However, should the duct pass through the fire barrier, now you have provided an opportunity to allow the fire to spread to the opposite side of the fire barrier.

So, getting back to the question at hand, how does one penetrate the fire wall without failing to be in compliance with NFPA 96?

My solution doesn’t require the vent to penetrate the firewall.

The firewall is rebuilt with a chase so that the vent runs INSIDE the chase… not through it.

The chase becomes the firewall between the space INSIDE it (that the vent is in) and the garage.

There is no penetration of the firewall.

The space INSIDE the chase running through the garage becomes part of the bakery (not the garage any longer) for firewall purposes.

Remember this isn’t a fellow inspector asking for advice on how he should relate information to his client, this is a building owner or builder, looking for an approved method of installation. THAT IS NOT WHAT WE DO. We identify, and refer. Under this circumstance, we should not be advising.

I am certified in mold inspections (and no, not through iac2), but I do not advise people on remediation practices and techinques, because I know what my limits are, legally and ethically. Maybe we should all represent this mindset.

When the installation fails, and he turns to the lawyer and shows where he got his approved plan, have fun with that.

This is nothing ingenious. It’s done regularly on ranch homes out east. The bedrooms in a ranch-style home are often above the garage. The heating supply ducts to the bedrooms often run up against the ceiling of the garage perpendicular to the joists (and so are below the ceiling of the garage). A drywalled chase is built around the duct so that the space INSIDE the chase becomes part of the bedrooms (for firewall purposes) not the garage any longer, even though the chase is below the garage ceiling.

But it is what I do. Commercial properties are my thing and I get asked for advice about commercial buildings every day of my life.

Nick… I have run into this situation before and doing what you said was enough to please the inspector.

Dylan… I think this is a good suggestion for John to present to the inspector. I do not think Nick would actually expect hime to do it without checking with the inspector. It is just a suggestion of a remedy.

Carmine writes:

Thank you.

However this is not a “ranch-style home” nor are we dealing with heating supply ducts. We are, however, dealing with ducts that get laden with grease and at which time can become easily ignitable. By penetrating the fire wall you create a way for a potential fire to migrate from one portion of the building to another which, had the wall not been penetrated, would not have been present.

I realize that this does not take into account the other safety measures that would be present (sprinklers, fire dampers, and so on) however the idea behind the original subject (kitchen duct passing through fire wall) is to not penetrate the fire wall so that products of combustion can not easily pass from the kitchen side to the opposite side of the fire wall should those other safe guards fail.

I’ll say it one last time. There is no penetration of the firewall using my suggestion. That’s why it complies with NFPA.