Storage Below Mezzanine Floor in Warehouse

[KLH]

Hello all,

I have a warehouse, masonry construction, 15 feet from floor to roof deck. A small mezzanine was built for uniform storage, with storage both above and below the mezzanine floor. Plywood "bookcases" are located under the mezzanine floor. The floor is constructed of plywood on 2"x10" wood joists. The top of the bookcases is 5" below the bottom of the wood joists. See attached picture.

2010 NFPA-13 is the relevant code.

Sprinkler have to be installed under this mezzanine floor. Since Figure 8.6.5.2.2 does not apply (light hazard only) do I need to tell the warehouse owner that he must cut his bookcases down to a point 18" below the sprinkler deflectors (See 8.6.6.1), which will be located an inch or two below the bottom of the wood joist?

Are there other options besides cutting the bookcases?

Thank you in advance.

 

[cdafd]

Tell him he shall provide proper protection per nfpa 13 and let him Fiqure it out

One option is a line between each "bookcase" in the area you can walk

 

[skdesigner]

NFPA 13-2010 8.5.6 is pretty clear when it comes to storage. The 18" rule is to allow the umbrella-shaped spray pattern to fully develop. If combustible storage was above the spray, the sprinkler would not be too effective.

Instead of cutting the bookcases down, why not just have the owner install a ~15" deep sheet of plywood across the top shelf to prevent any storage above that level? I would then do as cdafd suggests and run a line down the center of each aisle.