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Kiosks under Sprinklers

G

Glennman CBO

Silver Member
Joined
Oct 20, 2009
Messages
441
The 4' wide kiosk exception in the 2009 IBC, 903.3.3.

Does this limit the kiosk to 4' x 4', or can it be 4' x 8' and not be considered an obstruction? This kiosk would be not over 4' wide, but it would be 8' long.

Hmmm...
 
I am glad to see that ICC has started mandating installation requirements (sarcasm). Look at NFPA 13 (2010 ed) Section 8.6.5.3.3, there is similar language there where they only talk about width. However, in the NFPA example they mention ducts and the protection concept is related to continuous obstructions. You are allowed to have a duct that is 4' wide and is 100' long and not put a sprinkler under it. I would think that you would be allowed to have a kiosk that is less than or equal to 4' wide and is 8' long ....or 100' long for that matter.
 
A kiosk is on the floor and mostly combustible, wood & plastics. Duckwork is metal or fiberglass (limited in combustibles) installed close to the roof. I do not see the similarity you are trying to draw with relation to the length of a kiosk.
 
Is based on the NFPA 13 duct rule, the length is not regulated except as to, for malls, 300 sq ft total area. A 2-3 ft wide fake roof over the kiosk counter boxing in the employee is a common design.
 
IBC 903.3.3 mentions "covered" so I think the section has to do with the kiosk cover obstructing the above sprinkler spray from reaching the kiosk rather than the contents of the kiosk itself. NFPA's 4' rule is based on this being the limiting width (not length) that the ductwork, kiosk cover, etc. can be and still get coverage to the area beneath the obstruction. There is not a concern about the length because sprinkler coverage rules are going to ensure that the entire area is covered. The IBC commentary for 903.3.3 mentions the ductwork example which makes me think the requirement is directly related to the NFPA example and that width is mandated at 4' but not length.
 
I think that your concept is partially flawed, or else NFPA 13 would not have included this section: 8.5.5 Obstructions to Sprinkler Discharge.

if this section is was not properly applied, any ductwork that is over 4 feet in width and of any lenght would only require 1 sprinkler head to be complaint.
 
Both are based on the allowable 4' wide obstruction under the sprinkler preventing the designed discharge pattern from reaching the hazard. One must evaluate the sprinkler discharge (s.f. of coverage) and obstruction under the heads and the configuration of the branch lines in relation to the distances allowed between branch lines for lengths of obstructions. Example... a 100' long continuious obstruction is an obstruction if the obstruction exceeds 4' in width when it reaches or is located horizontal to the allowable distance of the parallel branch lines......sorry if this doesn't make sence....Tigers won again and I've had a few :)
 
Builder Bob said:
I think that your concept is partially flawed, or else NFPA 13 would not have included this section: 8.5.5 Obstructions to Sprinkler Discharge. if this section is was not properly applied, any ductwork that is over 4 feet in width and of any lenght would only require 1 sprinkler head to be complaint.
Click to expand...
NFPA 13 2010 8.5.5 is the general obstruction section and the 4' requirement is repeated in (SSP SSU) 8.6.5.3.3 from section 8.5.5.3. Keep in mind this is only for obstruction greater than 18" below the heads (from NFPA 13). As obstructions get closer to the heads the spacing requirements are governed by other tables.

Sometimes it is best to look at it from extreme examples. Think of a 1" pipe running through a space greater than 18" below the sprinklers. I think everyone would agree that is not an obstruction. Now a 2" pipe, now a 6" pipe and so on. The sprinkler installation code (NFPA 13) has made the limiting threshold for the continuous obstruction at 4' wide (regardless of length). I really think that IBC section 903.3.3 was trying to capture the NFPA 13 rule on 4' wide continuous obstructions. At this width, it is essentially considered another "ceiling" that needs protection. Which is probably why 903.3.3 refers to "covered" objects. If ICC is trying to require this for 4' by 4' objects, they must be utilizing obstruction research that I have not seen published in the industry.

And I agree that if only one head was installed under any ductwork that is over 4 feet in width and longer than 15 feet (for standard spray pendent or upright light or ordinary hazard) then this would not be proper application of 8.5.5 or 8.6 because additional heads would be required to be spaced along the length of the new "ceiling"/obstruction.
 
Thanks all...

This all makes sense with the 4 ft wide obstruction, but 100 ft long. The trouble is here is that the plans examiner doesn't "feel good" about it.

Go figure. I need some illustrations to show him. The comentary is useless in this area.
 
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