In February of last year I put together a flowchart that covered sprinkler requirements for exterior projections. If I had a Top-10 Articles list, it'd be on it.
If you haven’t read it,here’s a link to the original article.
Since I wrote this article and posted the original flowchart, I’ve received some encouraging feedback and thoughtful comments.
I’ve updated the flow chart this week to address specifically sprinkler protection of porte-cocheres:
What's a Porte-Cochere?
First, because I have no idea where the term “porte-cochere” originated, I’m talking about the covered entrance where vehicles can pass through as part of an entranceway to a building.
Not to point fingers, but I’m guessing the term “porte-cochere” was dreamed up by an architect to disguise the fact that they’re sticking a carport on the front of their building. Maybe it’s my Missouri roots, but what we’re talking about here are just fancy carports that can be driven through. Now stepping down from the soapbox…
"If It's Not Touching the Building..."
Stop me if you've heard this one before.
One common assumption I’ve heard repeatedly from architects and contractors concerning porte-cocheres is that sprinkler protection isn’t required for porte-cocheres if they are not connected to the main building.
Unfortunately, that's not justified by code.
It is true that porte-cocheres, on their own, often do not require fire sprinkler protection. They will generally fall under a Type U (Utility and Miscellaneous Group) Occupancy, which do not require fire sprinklers by IBC 903.2.
However, in order to qualify as a separate “building”, the International Building Code requires a physical space separation, a fire-rated separation, or a combination of both.
In terms of a porte-cochere attached to a main building, the porte-cochere would be considered a separate building by any one of the following:
As an example, if the main building is a Type V-B (combustible construction), Residential R-2 Occupancy (such as a Senior Living facility with more than 16 people), then the minimum requirements for a porte-cochere as a separate building would be:
From a practical standpoint, what is the difference between a porte-cochere that’s six inches from the main building and one that is touching the main building?
None. Zero difference.
I’ll explore this from a scientific perspective in next week’s article, but in short - conduction heat transfer makes little difference in the spread of fire from one structure to another.
Want to know why forest fires can “jump” across highways? It’s not because trees are locking branches above roadways – it’s because of radiative heat transfer.
So why do we get so tied to the concept that if the porte-cochere isn’t touching the main building that it’s as if it doesn’t exit? I’m not sure exactly, but it seems to come up quite frequently.
One Note on Concealed Spaces
NFPA 13 has two separate sections that affect porte-cocheres. The first is protection below overhangs, canopies, & porte-cocheres. This article and the flowchart address this situation. The second section is protection within concealed spaces.
If your porte-cochere does not require sprinkler protection per the building code, then no sprinklers are required regardless.
If that's not the case, and your porte-cochere has concealed spaces within it, check out NFPA 13's Special Situations section to see if the concealed spaces require sprinkler protection. These may still be required to be protected even when sprinklers can be omitted below the ceiling. This show ups in Section 8.14.1 of the 2002 Edition, Section 8.15.1 in the 2007-2016 Editions, and Section 9.3.18 in the 2019 Edition.
Losing the Forest for the Trees
I sometimes find that when assessing code it is easy to lose the forest for the trees.
Sometimes I can be so fixated on finding one specific answer that it is easy to step back and assess the ‘big picture’. Addressing overhangs and canopies can get that way.
While I don’t always get the opportunity to address fire protection intent with a building owner, I have to keep in mind that code only prescribes the minimum requirements. We can always elect to improve fire protection & life safety above code minimum.
Two recent local fires come to mind when looking at how sprinkler protection affects overhangs and how different owners were impacted very differently.
The first fire occurred at an apartment complex when a tenant left a lit cigarette on the third story balcony of an apartment complex. The cigarette started a fire on the unprotected balcony, which spread into the apartment attic (without draftstops) and quickly spread across the attic of the entire building. The upper two levels were badly damaged along with the entire attic and roof needing replacement.
Another fire occurred, more recently, at a three-story office with a porte-cochere. A car fire underneath the porte-cochere activated a single sprinkler which suppressed growth until the fire department arrived. The porte-cochere had smoke damage, but the fire had no impact to the main building. No downtime, no multi-million dollar rebuild. From the photos it was difficult to see any impact from just inside the main entrance.
These are two different situations of course; the first likely an NFPA 13R and the second an NFPA 13 system. Nonetheless it raises the issue of making sure that we, as professionals, inform and have dialogue with the building owner to not just determine what code minimums require, but what levels of protection may serve them best.
This Month's Sponsor
I'd like to introduce this month's MeyerFire sponsor with Engineered Corrosion Solutions. They are experts in the corrosion space for fire sprinkler systems and have a long list of helpful resources on their website.
As a side note, some of their original whitepapers and case studies were instrumental for me in my understanding of current corrosion challenges. When should we specify galvanized pipe? Is MIC or oxygen-induced corrosion a bigger concern? What can we do to stop corrosion entirely? They have it all here.
Thanks to the ECS team for helping promote this site and supporting my efforts to develop new resources for the industry.
Next week I'll explore the concept of porte-cochere separation distance, but from a modeling perspective. How much does the distance impact radiative heat transfer? How does convective heat transfer play a role? I'll explore this in more detail and from a calculated perspective next week.
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Joseph Meyer, PE, is a Fire Protection Engineer in St. Louis, Missouri. See bio on About page.