sprinkler above drop ceiling 1

[crb7]

Hi guys
Its about 5 days that Im researching about sprinkler above drop ceiling but I can decide its a mandatory to install sprinkler above drop ceiling or not. In NFPA there are a few clauses about drop ceiling.

8.15.23 Spaces Above Ceilings.
8.15.23.1 Where spaces have ceilings that are lower than the
rest of the area, the space above this lower ceiling shall be
sprinklered unless it complies with the rules of 8.15.1.2 for
allowable unsprinklered concealed spaces.
8.15.23.2 Where the space above a drop ceiling is sprinklered, the sprinkler system shall conform to the rules of
11.1.2 and Section 12.3.
8.15.23.3* Where there is a noncombustible space above a
noncombustible or limited-combustible drop ceiling that is
sprinklered because it is open to an adjacent sprinklered
space on only one side and where there is no possibility for
storage above the drop ceiling, the sprinkler system shall be
permitted to extend only as far into the space as 0.6 times the
square root of the design area of the sprinkler system in the
adjacent space

2016 version of NFPA 13 describes cloud ceilings but the ceilings in my project are not those types. I've read 8.15.1 Concealed Spaces but still cant decide about this subject.
May you help me?

 

[cdafd]

What is the construction material the building is made out of??

What is the construction material above the drip ceiling??

Steel

Concrete

Wood

Other

 

[crb7]

materials of building are steel and concrete.
above the drop ceiling are hvac ducts and pipes and electrical cables.

 

[cdafd]

Look at 8.15.1.2.1

For the simple answer. If no combustibles, such as wood are above the drop ceiling, No sprinkler protection is required.

If your contract calls for them or some other standard is used, that may change the answer.

 

[crb7]

tnx cdafd

8.15.1.2.1* Concealed spaces of noncombustible and limited combustible construction with minimal combustible loading having no access shall not require sprinkler protection.

what does "having no access" mean? Drop ceiling usually have access through removing tiles.

 

[UFT12]

whenever you hear "having no access" your mind should go to "potential storage". That's what the committee is concerned of. Any tile of such type of ceilings is practically an access point to the concealed space. I have encountered this situation many times and usually the insurance carrier request them for extra safety and/or lower premiums.The classification of the space below affects the judgment for such spaces as well. As this situation is always rather "grey", I suggest you consult either the AHJ or the insurer.

By the way, when the concealed space houses only electromechanical equipment and the entire concealed enclosure is non combustible, you should be eligible to omit sprinklers per the NFPA 13. This is somewhere stated in the annex of 13. But you should not rely only on 13.

 

[crb7]

tnx UFT12

I guess the clause you mentioned is :

A.8.15.1.2.1 Minor quantities of combustible materials such
as but not limited to cabling, nonmetallic plumbing piping,
nonstructural wood, and so forth can be present in concealed
spaces constructed of limited or noncombustible materials
but should not typically be viewed as requiring sprinklers (see
8.15.1.1). For example, it is not the intent of this section to
require sprinklers, which would not otherwise be required, in
the interstitial space of a typical office building solely due to
the presence of the usual amount of cabling within the space.
The threshold value at which sprinklers become necessary in
the concealed space is not defined.