Combustible Stairs

[coarts]

Nfpa 13 requires sprinklers beneath all stairs of combustible construction. To comply with this, I believe we need sprinklers at each floor landing, not just top and bottom as in non-combustible stairwells. Would this be correct or would someone say the mid-landings need sprinklers also. Thanks for your help.

 

[SprinklerDesigner2]

As I understand it you are correct. Under each landing if combustible.

 

[Oremus]

Wouldn't a sprinkler need to be installed under the stairs themselves as well if they're over 4 ft. wide? Similar to how you would put sprinklers under stairs in a warehouse where you just know someone's going to stack some boxes there...

 

[Haldorson]

What about a 30' long linear combustible stairway with sloped ceiling and a landing a halfway down the stairs. Do we install 5 sprinklers total: 1 to protect the top landing, 1 to protect below the top landing, 1 to protect above the mid-landing, 1 to protect below the mid-landing, and 1 to protect the bottom of the stairway?

 

[cdafd]

Coarts seems like you are talking to different conditions

1. Protection under combustible stairs and that depends on if they are emclosed or not and if enclosed do they meet an exception

2. Than you talk about protecting the landing, which I take to mean sprinklers at ceiling level to protect the walk way.

So do you want to restate your question or am I wrong?

 

[coarts]

Its a 4 story building with V-B construction NFPA 13 system. Enclosed stair shafts are 2 hour rated but entire stair inside is wood. There are mid-landings that are 48" wide. Since the code says "sprinkle BENEATH all combustible stairs" I am thinking that every landing including the mid landings need to be covered and not just the top, bottom, and main floor landings. The size of the stairwell is 21 foot from front to back, so trying to make it work with one head at main landings would be difficult if spray needs to cover all the way to back of mid-landings. Does the code for sprinklering shafts come into play, or is a stairwell considered differently code wise?