“Does this canopy need sprinklers?” “Are sprinklers required below the porte-cochere?” “I have a residential balcony; does it need sprinklers?”
It's one of the most common design questions in commercial buildings with fire sprinkler systems; you’ve undoubtedly encountered it yourself.
The decision isn’t something that is taken lightly, either. In climates where freezing occurs, dry-sidewall sprinklers are often used for shorter-length projections. With new antifreeze systems are not an option (antifreeze must be a listed, pre-mixed solution which is not currently available), larger exterior projections could require dry sprinkler systems with increased cost, maintenance, and greater susceptibility to corrosion.
Non-combustible overhangs without combustible storage beneath typically don't require sprinklers, but the process to determine whether sprinklers are required is not always clear-cut.
Good Design Judgement
Before diving in on whether sprinklers are required or not, remember that good design judgement is always important. Just because certain code verbiage or annex material exists does not mean you, as a designer, engineer, or review authority, should forfeit good judgment or common sense. These are life safety systems and you were blessed with the ability to think analytically for good reason.
Soapbox aside; canopies, overhangs, and porte-cocheres provide a unique challenge in that they can compromise a building by (1) subjecting the building to trapped convective heat, (2) radiate heat down to the base of the fire and encourage further growth, (3) provide a continuous fuel path to the building.
NFPA 13 addresses exterior projections in Chapter 8 (2002 Edition: Section 8.14.7, 2007-2016 Editions: Section 8.15.7, 2019 Edition: 18.104.22.168 and 22.214.171.124). There are five paragraphs in this section, and while they appear straightforward there are two critical words that tend to throw a figurative wrench into every situation.
Two Words that Complicate Everything: “Combustible Storage”
NFPA 13 126.96.36.199 (2016): Sprinklers shall be installed under exterior projections greater than 2 ft (0.6 m) wide over areas where combustibles are stored.
What constitutes combustible storage? Storage of any item that can burn? What about temporary placement or handling of items – would they not burn in the same fashion that long-term storage would?
While not enforceable unless specifically adopted by a jurisdiction, annex material within NFPA 13 offers guidance in interpreting what is considered “combustible storage”.
Temporary or short-term items, such as parked vehicles or delivered packages, while combustible, would not be considered ‘storage’ (NFPA 13 2007-2016 Annex A.188.8.131.52 and A.184.108.40.206, 2019 A.220.127.116.11).
Minor amounts of combustibles may also not justify sprinklers, such as planters, newspaper machines, or combustible furniture on balconies for occupant use (NFPA 13 2002 Annex A.18.104.22.168, 2007-2016 Annex A.22.214.171.124, 2019 A.126.96.36.199).
Temporary loading and unloading of vehicles, according to the Annex material in NFPA 13, doesn't necessarily justify sprinklers. However, good judgement is critical especially when protecting high-priority facilities like hospitals.
Conversely, an exterior loading dock is designed to accept incoming shipments which inevitably end up residing below canopies while loading and unloading occurs, even if only temporary. While long-term storage might not occur, it could be reasonably argued that enough shipping items, pallets, boxes, or other items could collect to be considered “combustible storage”.
Projections above the only means of egress or exterior ceilings where the building is occupied above is also suggested to require sprinklers (NFPA 13 2007-2016 Annex A.188.8.131.52, 2019 A.184.108.40.206). Either of these arrangements, if not protected, could reasonably compromise the egress ability or occupied areas above and could be justification for providing sprinklers.
Parking areas that are not used for pickup and drop-off are another example of combustibles that would be present long-term, which the annex does not exclude.
Loading docks are used for transitioning shipments to the building, so collection of combustibles underneath an overhang could be a common occurrence.
Judgement by the Designer and Authority Having Jurisdiction (AHJ)
If so much of the guidance is provided in the unenforceable annex material and the body of NFPA 13 is vague about combustible storage, how do we determine when sprinkler protection is required? Ultimately, the determination of whether a situation requires sprinklers due to the amount of combustible storage is up to the Authority Having Jurisdiction. It is a judgement call that is based on the amount of combustibles and length of time where combustibles would be present.
An Exterior Projection Cheatsheet
While the judgement of amount of combustible storage resides with the AHJ, here is an updated and expanded flowchart based on the body and annex material of NFPA 13 to help guide the decision process (original published by the National Fire Sprinkler Association in a TechNotes in May 2007):
Get this free, printable PDF quick-guide to Canopy, Overhang & Exterior Projection Requirements here:
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Joseph Meyer, PE, owns/operates his own Fire Protection Engineering practice in St. Louis, Missouri. See bio on About page.