Sprinklers under underside of OPEN stair run??

[av610]

I was wondering what kind of protection is needed for the underside of the stairway (attached) if any? The stair run is 4'=6" wide.

Thanks

 

[cdafd]

Normally see run down the slope of the escalator

Spaced to cover area under the escalator

Do you also have to provide opening protection ???

 

[cdafd]

http://www.rogersarkansas.com/fire/...rotection of Vertical Openings by NFPA 13.pdf

 

[av610]

I saw that post and is helpful for the Vertical Opening aspect. However, I am still trying to determine if any protection is needed on the UNDERSIDE of the stair way since it is not enclosed.

The first stair landing is at ~6'-10" while the top of the stair will hit the next level at 16'-0"

Here are some pictures i found on google:

http://www.aw-systems.com/images/gallery/mezzanine/fire-suppression-under-stair.jpg

http://cpluscdesign.com/gastography/wp-content/uploads/2011/08/IMG_0299w.jpg

thanks.

 

[cdafd]

Yes required obstruction of overhead sprinklers
Over four feet wide

 

[cdafd]

8.5.5.3* Obstructions that Prevent Sprinkler Discharge from Reaching Hazard. Continuous or noncontinuous obstructions that interrupt the water discharge in a horizontal plane more than 18 in. (457 mm) below the sprinkler deflector in a manner to limit the distribution from reaching the protected hazard shall comply with 8.5.5.3.


8.5.5.3.1* Sprinklers shall be installed under fixed obstructions over 4 ft (1.2 m) wide.