What Is the Minimum Distance You Can Store Objects From a Sprinkler Head?

Charts and lawmaking from NFPA aid installers and facilities managers determine the distance required between fire sprinkler heads and objects

How much distance do fire sprinkler heads need from obstructions, whether permanent or temporary? It's a concern with large impacts for every sprinklered building. Declining to place the proper distance between sprinklers and obstructions tin cease the burn sprinkler from discharging on time—or will prevent sprinklers' spray from reaching a fire or wetting materials that will burn.

In part ii of our series on distances for fire sprinklers, we look at some of these sprinkler head obstruction distance rules for standard spray sprinklers—a common sprinkler type that uses different rates of discharge to defend against a broad range of hazards. We provide an overview of what the NFPA requires for obstructions—both permanent and temporary—and accept a closer await at some fundamental rules on the subject:

• What is an obstruction and where are the rules regarding it plant?
• Which obstacle rules apply to standard spray pendent, upright, and sidewall sprinkler heads?
• Which rules apply specifically to standard spray pendent and upright heads?
• Which rules apply specifically to standard spray sidewall heads?

This blog does non encompass distances between sprinklers and walls (or between sprinklers)—for those, read Maximum and Minimum Sprinkler Distance Rules, Part 1: Standard Spray Fire Sprinklers.

If you're in the process of installing or replacing sprinklers, nosotros invite you to look at our selection of commercial fire sprinklers, including standard spray models, from industry-leading manufacturers like Senju, Victaulic, Tyco, and Reliable (RASCO).

Fire sprinkler head obstructions are covered in NFPA 13 and NFPA 25

What is an obstacle? NFPA thirteen : Standard for the Installation of Sprinkler Systems defines two types:

From the 2022 edition of NFPA 13

three.3.133 Obstruction.

three.3.133.i Continuous Obstacle. An obstruction located at or below the level of sprinkler deflectors that affects the discharge pattern of two or more than adjacent sprinklers.

3.3.133.2 Noncontinuous Obstruction. An obstruction at or beneath the level of the sprinkler deflector that affects the discharge blueprint of a single sprinkler.

The NFPA xiii Handbook notes that these terms emerged to help installers ameliorate understand the NFPA's intent regarding the placement and spacing of sprinklers. These definitions go far articulate that it's the impact on sprinklers, and not the blueprint of the obstacle itself, that matters.

NFPA 13 deals largely with permanent obstructions—construction features that threaten to disrupt sprinklers' spray patterns. But for those tasked with the ongoing care of fire sprinkler systems, there's the affair of distances from temporary obstructions. We've taken a expect at these in our multi-part series on what facility managers need to inspect on a fire sprinkler organization.

In a nutshell, NFPA 25 : Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems says that objects that can block a sprinkler's spray must be at least eighteen inches away from the deflector. (That's the pocket-sized metal part at the sprinkler'due south forward edge.) There is an exception, however: In-rack sprinklers that are specifically designed for storage racks don't observe this minimum requirement.

These boxes should be at least 18 inches abroad from the deflector. Source: Metropolis of Montgomery, Ohio

And in a few cases, 18 inches from obstructions isn't plenty. Sprinklers designed for specific hazards or features (special sprinklers) crave three feet of clearance, as do those covering stored rubber tires. Further, state and local burn codes may override these sprinkler head obstruction distance rules and require greater clearance between sprinkler heads and storage.

All standard spray fire sprinklers must reduce risks from a multifariousness of objects

While NFPA 13 addresses the subject of obstructions largely by sprinkler type, all standard spray sprinklers share a few common provisions presented in affiliate ix.

Sprinklers must minimize obstructions to discharge in accordance with 9.five.five.two and ix.v.v.3 or additional sprinklers must exist added to provide adequate coverage (section nine.five.5.1). Farther, if an obstruction is no more than 18 inches nether deflectors—and if it prevents the sprinkler'due south blueprint from developing—nearby sprinklers must follow the minimum distance guidelines in affiliate ten (ix.5.5.ii)

If the obstruction is more than 18 inches below the deflector—and interrupts that belch in a horizontal airplane—it must comply with the guidelines of section 9.5.5.three, which addresses:

• Sprinklers under obstructions. Obstructions over 4 feet wide, including open-grate flooring, require sprinklers underneath (9.v.5.three.1 and 9.5.5.3.1.1). However, grate sprinklers must exist protected against discharge from other sprinklers (9.5.5.3.iv). Sprinklers below an obstruction must accept their deflectors placed directly under it or inside three inches (horizontally) of the obstruction'due south outside edge, and may be anywhere from 1 to 12 inches below it (nine.5.v.3.1.ii and 9.v.v.three.1.4).
• Noncombustible textile. If the obstruction won't burn, and its base of operations is no more than two feet in a higher place the floor, sprinklers aren't needed underneath (9.v.5.3.1.5).
• Temporary obstructions. Section 9.5.5.3.two states that large conference tables and other objects that aren't fixed in place don't need sprinklers beneath them.
• One sprinkler at the highest ceiling level may serve a closet or compartment at or under 400 cubic feet in size—regardless of obstructions (ix.5.5.4)
• Sprinkler types. Excluding overhead doors—which may take standard spray sprinklers underneath them—sprinklers below obstructions must be of the same blazon as those installed at the ceiling (9.five.5.3.iii and 9.five.5.3.three.1).

Grated floors like the ones found in theater catwalks may crave fire sprinklers beneath them. Source: InCord

NFPA charts prescribe distances from obstructions to pendent or upright sprinklers

Each sprinkler must be positioned to minimize obstructions that foreclose it from activating on time. Department 10.2.i.2 of NFPA thirteen provides a few ways for pendent and upright sprinklers to comply with this requirement:

• Place the sprinkler in accordance with table 10.two.seven.i.2 (shown below).
• For obstructions under four feet broad, installers may identify sprinklers on opposite sides of the obstacle (so long as the distance between each sprinkler and the obstruction'southward centerline doesn't exceed half the distance allowed between sprinklers—meet part 1 in this series).
• If a soffit or similar obstacle against a wall is no more than 30 inches wide, the sprinkler'due south deflector may exist positioned in compliance with Table 10.2.vii.ane.2. If it's less than 24 inches wide, the deflector may be as high to a higher place the bottom of the obstruction as the installer wants—provided that it remains sufficiently close to the wall (again, run into our previous web log to make up one's mind that altitude).

Nigh of these rules refer to table 10.2.vii.one.ii. This tabular array determines an appropriate distance betwixt the sprinkler's deflector and the bottom of an obstruction. As the distance from the fire sprinkler caput to the obstruction's side increases, and so does the permissible vertical distance. Annotation also that the distance between the deflector and the side of the obstruction is measured from the deflector's middle.

The letters "A" and "B" in the table below refer to dimensions shown in these illustrations from NFPA 13. Click hither or on the in a higher place image for a larger version.

From the 2022 edition of NFPA thirteen

TABLE 10.2.vii.one.2 Positioning of Sprinklers to Avoid Obstructions to Discharge [Standard Spray Upright/Standard Spray Pendent (SSU/SSP)]
Distance from Sprinklers to Side of Obstruction (A)						Maximum Allowable Distance of Deflector Higher up Bottom of Obstruction (B) [in. (mm)]
Less than 1 ft (300 mm)						0 (0)
1 ft (300 mm) to less than 1 ft six in. (450 mm)						2 1/2 (65)
1 ft vi in. (450 mm) to less than 2 ft (600 mm)						iii one/2 (90)
2 ft (600 mm) to less than 2 ft 6 in. (750 mm)						5 1/ii (140)
two ft half dozen (750 mm) in. to less than three ft (900 mm)						seven 1/ii (190)
3 ft (900 mm) to less than iii ft 6 in. (1.1 g)						9 1/2 (240)
3 ft 6 in. (1.1 m) to less than 4 ft (ane.ii m)						12 (300)
four ft (1.2 yard) to less than 4 ft 6 in. (1.four m)						14 (350)
4 ft 6 in. (one.4 grand) to less than 5 ft (ane.five m)						16 1/two (415)
5 ft (ane.5 m) to less than five ft half dozen in. (1.7 chiliad)						18 (450)
five ft 6 in. (i.seven g) to less than 6 ft (1.eight thou)						20 (500)
6 ft (ane.8 thou) to less than 6 ft 6 in. (2.0 g)						24 (600)
6 ft 6 in. (2.0 grand) to less than 7 ft (ii.1 k)						30 (750)
7 ft (ii.1 m) to less than 7 ft half-dozen in. (2.three k)						35 (875)

Sprinkler head obstruction distances on an contrary, side by side, or the same wall every bit a sidewall sprinkler are slightly different

Standard spray sidewall sprinklers are especially sensitive to obstructions. Every bit the NFPA 25 Handbook notes, these sprinklers are designed for unobstructed construction. While some obstructions are unavoidable, nearby lite fixtures and beams that can be accounted for tin prevent proper coverage.

A sidewall sprinkler can't exist installed less than four feet from an obstruction unless:

• The greatest dimension of the obstruction is less than two feet. In that example, the sprinkler must be at least three times that dimension away from the obstruction. For instance, a sidewall sprinkler requires iv feet of distance from an obstruction that has a maximum dimension of sixteen inches (ten.3.6.ane.1 through 10.3.six.1.two.1).
• The bottom of the fixture is above the airplane of the sprinkler'south deflector (10.iii.6.1.ii.two).
• The obstruction projects from the wall where the sprinkler is mounted (10.three.vi.one.4). These isolated obstructions must be located at least 4 inches from sidewall heads (10.3.6.1.4.ane).

Installers may also place sidewall sprinklers on each side of an obstruction under four feet broad (10.3.6.1.5). Simply like pendent and upright sprinklers, the distance between sidewall heads and the obstacle's centerline can't exceed half the distance allowed between sprinklers (read more here). Additionally, when a sidewall head and the obstacle are on contrary walls, that obstruction may exist as big equally two feet deep and two feet wide (10.iii.half dozen.1.six).

NFPA 13 provides the required distances from standard spray sidewall sprinklers in tables x.iii.6.i.3 and 10.iii.6.1.iv. The commencement table provides the required distances for sidewall sprinklers located four feet or more from an obstruction. The second tabular array addresses obstructions that share a wall with a sidewall sprinkler. In both instances, the distance between the deflector and the bottom of the obstacle is measured from the deflector'south centre in a vertical line. The distance from the sprinkler to the side of the obstacle is measured in a horizontal line from the obstacle to the center of the sprinkler'south deflector.

The messages "A" and "B" in these images correspond with distances provided in two tables. The image on the right addresses obstructions on a wall shared with the sprinkler, while the left-hand image depicts a sprinkler and an obstruction on adjacent walls. Click here or on the higher up epitome for a larger version. Source: NFPA xiii

Distances betwixt sidewall heads and obstructions on adjacent walls (NFPA 13, 2022 edition)

Tabular array 10.3.6.1.three Positioning of Sprinklers to Avert Obstructions (Standard Sidewall Spray Sprinklers)
Distance from Sidewall Sprinkler to Side of Obstruction (A)						Maximum Allowable Distance of Deflector Higher up Bottom of Obstruction (B) [in. (mm)]
four ft (i.2 m) to less than five ft (1.5 m)						i (25)
5 ft (1.5 thousand) to less than five ft half-dozen in. (1.vii 1000)						2 (fifty)
5 ft 6 in. (i.vii g) to less than 6 ft (one.viii m)						iii (75)
vi ft (i.8 m) to less than 6 ft 6 in. (2.0 one thousand)						four (100)
6 ft 6 in. (two.0 m) to less than 7 ft (ii.1 g)						half dozen (150)
7 ft (two.i m) to less than 7 ft 6 in. (2.3 m)						7 (175)
7 ft 6 in. (2.3 m) to less than eight ft (ii.4 m)						9 (225)
8 ft (2.4 m) to less than 8 ft 6 in. (2.6 chiliad)						11 (275)
viii ft 6 in. (2.6 m) or greater						fourteen (350)

Distances for sidewall sprinklers sharing a wall with an obstruction (NFPA xiii, 2022 edition)

Table ten.3.6.1.4 Positioning of Sprinklers to Avoid Obstructions Along Wall (Standard Sidewall Spray Sprinklers)
Distance from Sidewall Sprinkler to Side of Obstacle (A)						Maximum Allowable Distance of Deflector Above Bottom of Obstacle (B) [in. (mm)]
4 in. (100 mm) to less than 6 in. (150 mm)						1 (25)
6 in. (150 mm) to less than 1 ft (300 mm)						2 (l)
ane ft (300 mm) to less than 1 ft half-dozen in. (450 mm)						3 (75)
1 ft 6 in. (450 mm) to less than ii ft (600 mm)						4 1/2 (115)
two ft (600 mm) to less than ii ft 6 in. (750 mm)						5 three/4 (145)
two ft 6 in. (750 mm) to less than 3 ft (900 mm)						7 (175)
3 ft (900 mm) to less than 3 ft half dozen in. (1.1 thousand)						8 (200)
3 ft 6 in. (ane.1 1000) to less than 4 ft (i.ii g)						9 1/iv (230)
4 ft (1.2 m) to less than 4 ft half dozen in. (1.four grand)						10 (250)
4 ft 6 in. (ane.four one thousand) to less than 5 ft (1.5 thou)						eleven 1/2 (290)
5 ft (ane.v thou) to less than 5 ft 6 in. (ane.7 1000)						12 3/4 (320)
v ft 6 in. (1.7 m) to less than 6 ft (1.8 m)						14 (350)
half-dozen ft (1.8 m) to less than 6 ft 6 in. (ii.0 g)						fifteen (375)
6 ft six in. (two.0 m) to less than vii ft (ii.2 m)						16 1/4 (410)
seven ft (two.ii one thousand) to less than seven ft six in. (ii.three m)						17 1/2 (440)

We've just scratched the surface of NFPA 13's sprinkler head obstruction distance rules

This concludes role 2 of our look at NFPA 13's rules regarding distances for sprinkler heads. We've covered the core sprinkler head obstacle distance rules for standard spray heads—and while they're the most common type, they're merely one of several addressed past the standard. For more, check out part one in our series on distances for standard spray sprinklers, and stay tuned for our next entry in the serial.

This commodity is just one modest part of QRFS's endeavor to assist contractors, consumers, and burn down safety professionals stay in compliance with standards and codes. If you're on the hunt for new or replacement fire sprinklers, take a wait at QRFS'south pick of commercial burn down sprinkler heads. Our sidewall, pendent, and upright heads are available in temperatures ranging from 155 degrees to 286 degrees Fahrenheit, with a diversity of finishes and comprehend plates to match buildings of all kinds.

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