Sprinkler protection under open stairs?

[Bagge]

Hi,
I have a question which is a little hard for me to figure out. I've attached a sketch showing the case. I have a parking garage which is fully sprinkled. This parking garage is not ended with a normal wall, but with some open stairs, which is 30% open (see the sketch). Above the staircase is open sky. There will be cars parked under the stairs, so there is a risk of fire. I am unsure whether sprinklers will activate, or the heat will just penetrate past the sprinkler through the stairs to the sky because of the 30% opening? Maybe it's better to mount smoke detectors under the stairs and sprinklers inside the parking garage? But the problem is that the garage is under a demand that says it should be fully sprinkled. The location is by the way in Denmark, if someone should wonder

Hope somebody can please help me with an advice?

 

[spkreng]

Bagge, it seems to me, without benifit of a plan view that you have the sloped area covered, wouldnot a water curtain at the end of the completly covered area before the stair effectively seperate these? and do away with the spkrs under the stair calling it "exterior adjacent stair", besides depending on the dimentions one might be needed, would like to see a floor opening / plan view.

 

[KLH]

What is the purpose of the check valve in Figure A.8.17.5.2.2(b) in NFPA-13 2010?

Thanks in advance.