Two story building with mercantile first floor (no sprinklers) and sprinklers 13R on second floor

[SprinklerDesigner2]

The engineer of record is telling me we have a two hour floor assembly separating the non-sprinklered first floor mercantile occupancy with tenants on the second floor apartments.

There are no plans to provide sprinklers in the mercantile occupancies and it just didn't feel right with me so I asked again to cover my rear end.

The response was:

In response to question 1, we are not sprinkling the first floor so his beam concerns at first floor framing are not applicable. We envision fire sprinkler riser in the riser room with piping at the underside of the 2-hour rated horizontal assembly then risers up the chases between the corridor closets at second floor to serve second floor residential units.

The supply pipe is run in the non-sprinkled mercantile space and it appears it will be run exposed. Seems strange but the email, from the engineer of record through the architect, is my get out of jail free card but I am still curious and wondering if any of you ever run into something like this before?

 

[skdesigner]

As long as they haven't snuck some sleazy sentence into the specs like 'sprinkler contractor is responsible for confirming this methodology is acceptable', you're probably just fine with that RFI response. NFPA 13 tells us how to install sprinklers. The 'when' is left up to the people who drive BMW's, not Chev half-tons.

We run into all kinds of nutty things, partial-area sprinkler systems being far from the nuttiest. I have learned to make my RFI's extremely pointed and unambiguous. That way when things go south at the end of the job, the red faces are on the other side of the table. And the change orders get an extra zero added to them.

 

[MGXFP]

My understanding is the mercantile building is a separate building per the code and the 2 hour separation is the demising line between it and the residential occupancy above. The mercantile building is either small or the construction type/ fire resistance has been increased would be my guess.

Generally sprinklers are the cheaper route than increased fire resistance of the lower building, so no I have not seen this done before. My opinion is the fire sprinkler system in the unsprinklered portion of the facility should be protected by rated construction or fire sprinklers. I know you'll keep a copy of that email forever and ever!

 

[skdesigner]

Wouldn't that be considered a 'Podium Building' and therefore require 3 hour separation?

 

[SprinklerDesigner2]

skdesigner, you are so very right when it comes to making RFI's "extremely pointed and unambiguous". I too drive a Chevy truck and not a BMW.

With the response I received through the architects email IF something comes up the worst thing that can happen to me is I get a nice change order for some big $$$.

I'm just curious about running exposed sprinkler pipe through an unsprinklered mercantile space.

And yes, copies of that email are numerous and better protected than the Declaration of Independence.

 

[skdesigner]

It looks like more of a 'should' statement in 13.

A8.1 ... 'All openings should be protected in accordance with applicable standards, and no sprinkler piping should be placed in an unsprinklered area unless that area is permitted to be unsprinklered by this standard'.

Maybe one more follow-up RFI asking, point blank:

Please confirm that it is acceptable to install the sprinkler main exposed (i.e no protection) in the unsprinklered portion of the building.

 

[stookeyfpe]

What is the adopted building code in the jurisdiction? The answer is in the Building Code, not NFPA 13.

 

[SprinklerDesigner2]

Stookey,

State of Georgia IBC

International Building Code, 2018 Edition, with Georgia Amendments (2020)
International Fire Code, 2018 Edition (Contact State Fire Marshal Below)