Some concerns about rack tire storage with a grated mezzanine.

[SprinklerDesigner2]

This is a small tire store having five service bays where people can get tires worked on and changed. Similar to a Midas Muffler Shop only for tires.

The new tire storage area covers approximately 25'x70' and is open to the service bays.. no wall separating tire storage from the service areas.

Obviously any protection scheme would have to extend at least 15' beyond so we're looking at an area of 40'x85' since tires are stored in a corner.

Specifications call for an ESFR system for protection of rack storage to 19'-0" high or anything else that works within the standard. Personally I don't see how anything could could work and I did see one project, in another state, where the contractor installed two layers of sprinklers as if the mezzanine floor was solid which is obviously is not.

Photo's taken at a store in operation to provide a better idea what we are dealing with.

The tire racks themselves are open through the grated mezzanine but the problem I have with this set up is under the grated mezzanine walkways with an ESFR sprinkler overhead. I think it is clear additional sprinklers need to be beneath the grate but to what design criteria?

 

[cdafd]

Like what appears to be Romex wire for the lights

Appears if in an ahj with IFC to be high piled stock chapter 23

 

[SprinklerDesigner2]

There is no doubt it's high piled stock which should be covered using NFPA #13 2013 TABLE 18.4(d).

The issue I have is the protection below the grated mezzanine which is obviously required.

 

[stookeyfpe]

SD2:

A better approach is to make the decking solid but probably won't be an option. Your best option is to design the in-rack sprinklers per Section 18.5.

In my humble opinion I think FM LPDS 8-3 is going to give you more guidance. Frankly when I read Chapter 18, it looks like nothing but a compendium of fire test data from tire manufacturers. It clearly doesn't address situations that you presented.

My two centavos,

 

[MatthewJWillis]

To the same design criteria as overhead. What you have is an obstruction located below the sprinkler. Open grating is specifically mentioned in 13 under the "Obstructions greater than 4'-0" section.
You must follow the obstruction guidelines for the specific ESFR you are using. Also do not forget that they must be protected from overhead discharge as well. See section 8.12.5 of the 2013 edition of 13.

 

[TravisMack]

We have done these in the past. The solution was very similar to what Matt said. We basically did ESFR at the roof, then routed ESFR under the grated mezzanine. Also, the AHJ wanted a 12"x12" water shield at each sprinkler. Just did a piece of sheet metal with a hole and fender washers to hold in place. Everyone seemed happy with the final product.

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com

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[cdafd]

Do most esfr heads require three feet clearance to top of storage?


And are they listed for protection of tires

 

[SprinklerDesigner2]

Travis,

You used ESFR underneath the grate?

What did you use for design basis?

 

[TravisMack]

We did 12 sprinklers at the roof and 2 below the grating. We did keep the branch lines the same size. It was literally treated as you would any obstruction >24" in width.

These usually have big pipe. I think we had 6" mains at the roof and 2" branch lines. We ended up with 4" mains and 2" branch lines below the grating.

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com

"Follow" us at

https://www.facebook.com/pages/MFP-Design-LLC/92218417692