INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Jobs

Smoke detector spacing with low height ceiling and beams.

Smoke detector spacing with low height ceiling and beams.

(OP)
Hello.
A question on smoke detector spacing/location.

Case:
Intermediate floor with low ceiling.
Ceiling height: H=2m (6.7´)
Beam height: h=0.38m (15")
Beam distance: L=1m (3.3´)

For smoke detectors: since h>0.1H, and L>0.4*H >them each beam space is a pocket so I need a @#%& lot of detectors.

On "beam reduction rules" as per NFP72, or an manufacturers rules is there a consideration for low ceilings?.
Do reduction rules on detector spacing apply the same if the ceiling is relatively low?

RE: Smoke detector spacing with low height ceiling and beams.

What kind of business are they going in??

Why are they required?

RE: Smoke detector spacing with low height ceiling and beams.

(OP)
Client requirement. Used for storage of working materials, temporary storage of tools, access to other areas.In the sketch I describe. (not on scale).
Following NFPA 72, I interpret the upper level shall be considerd a different case.
The detector spacing looks fine for the high ceiling area, but in the upper level the size of beams lead me to a detector in each beam pocket.


RE: Smoke detector spacing with low height ceiling and beams.



A little beyond my little knowledge.



I do not think you can get a reduction for low ceiling, unless some engineering analysis is done?



Waiting for Scott to answer you.



From the 2013 edition, does this help you::





Looks like you fall between a solid joist and a beam.



If all else fails, can they sheetrock the area?? And make it smooth? would it be cheaper in the long run?







17.6.3.3* Beam Construction.



17.6.3.3.1 Spacing.



17.6.3.3.1.1 A ceiling shall be treated as a smooth ceiling if the beams project no more than 4 in. (100 mm) below the ceiling.







17.6.3.3.1.2 Where the beams project more than 4 in. (100 mm) below the ceiling, the spacing of spot-type heat detectors at right angles to the direction of beam travel shall be not more than two-thirds of the listed spacing.







17.6.3.3.1.3 Where the beams project more than 18 in. (460 mm) below the ceiling and are more than 8 ft (2.4 m) on center, each bay formed by the beams shall be treated as a separate area.









17.6.3.3.2 Location. Where beams are less than 12 in. (300 mm) in depth and less than 8 ft (2.4 m) on center, detectors shall be permitted to be installed on the bottom of beams.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close