FM Global and Baffle Requirements Separating Standard Response from Storage (ESFR) Sprinklers

[SprinklerDesigner2]

I have an older 200,000 sq ft warehouse which used standard response K=8.0 uprights and today they want to store plastic products.

FM Global wants Data Sheet 8-9 Table 10 and with the building height 35'-0" it appears we have a choice between 12 K22.4 @ 75 psi or 12 K25.2 @ 60 psi.

Yes, we are looking at a tank and 2,000 gpm pump because the city doesn't have enough water.

The building has 50' bays, 2'-6" open web steel joists (5'-0" OC) with 30" solid metal beams.

I can't find the requirement for baffles to separate the older SR and newer QR storage sprinklers and I know the baffle requirement details HAS to be somewhere.

If I remember right it used to be in 2.0 but I can't find it anywhere.

What I am thinking of doing is extending the area of application a little farther to the 30" steel beams and use them as the baffle.

And is the depth of the baffle 2'-0" or is it more? I seem to remember 2'-0" being the standard but I need to make darn sure.

There's a 2" open space above the beam and roof deck where the joists sits on the solid beam. I don't think that has to be sealed if I remember correctly.

Can anyone point to where I can find the requirements for baffles FM?

Yeah, fans have to be moved but this gives a good idea what we are dealing with.

 

[SprinklerDesigner2]

Silly me!

The correct wording is Draft Curtains and not Baffles.

This isn't the first time I have had this trouble and I think it stems from decades ago when I first heart the term it was "baffles" and I can't get it out of my mind.

2.1.3.2 Draft Curtains
See Data Sheet 2-0, Installation Guidelines for Automatic Sprinklers, for recommendations related to the use of draft curtains in the presence of Storage sprinklers.

Anyone deal with a solid metal beam where you have a 2" horizontal opening between the roof deck and top of a 24" beam? Would the beam itself serve as a "draft stop"?

 

[cdafd]

How far down does FM say a draft curtain has to be?

Nfpa 13 is 2 feet

I would say the gap has to be blocked off

 

[SprinklerDesigner2]

So I spent New Year Day going over FM Data Sheets 1-10 "INTERACTION OF SPRINKLERS, SMOKE AND HEAT VENTS AND DRAFT CURTAINS" , 2-0 "INSTALLATION GUIDELINES FOR AUTOMATIC SPRINKLERS" and 8-9 "STORAGE OF CLASS 1, 2, 3, 4 AND PLASTIC COMMODITIES".

For what it is worth I don't care about NFPA or any building codes have to say about the issue because where this job is located the policy of the AHJ's is if FM Global Approves then it is good to go.

It is clear to me the depth of the curtain is a minimum of 2'-0".

What I want to do is use the 36" solid beam at Column Line J as the baffle and as you can see that column is 50'-0" away from the nearest plastic storage.

My big question is are we required to have an aisle centered below Column J as shown on Data Sheet 1-10 Fig. 1?

If I had to give an answer right not it would be yes but my question is "why?" I have the baffle and I am at least 50' away from any plastic storage so why the aisle?

I don't know if the customer wants to construct an aisle at Column Line J. Given the information I provided how wide would you say that aisle has to be?

The last thing I want to do is construct a baffle in the bay perpendicular to the bar joists. What a monster. With the solid beam all I have to do is fire stop the space above the bean to the roof deck, about 2", and I am done. Easy.

Perpendicular, in my mind, is a 300' monster.

For what it is worth 12 K25.2 @ 75 psi is the heaviest system I have ever done if with a 150 psi (175 @ churn) 2,000 gpm pump. I got monster pipe. 2,581 gpm at source with 250 gpm hose stream.

So your thoughts are most appreciated but know I will be contacted FM Global once I understand this more clearly a little more.

 

[cdafd]

So do you want to have storage closer to column j?

What will be on the other side of column j??
Storage? Open floor? Other?

My two thoughts for the aisle

Radiant heat

Firefighter access

 

[SprinklerDesigner2]

cdafd,​

So do you want to have storage closer to column j? Yes, I would like to see storage under column J.

If we have the exact same commodity a Class III commodity on both side of the draft curtain why would we need an aisle if both sides are properly protected with the storage sprinklers and the existing SR uprights?

What will be on the other side of column j? Class III commodity both sides.

Storage? Open floor? Other? Storage, Solid Pile Class III.

Thank you for responding and I am looking for is a way where I can use the solid 36" beams for the draft curtain. The draft curtain will extend 300' across the building and if I can use the solid beam life is easy as all I would have to do is fire stop the 2" space between the top of the beam and underside of roof deck. Not a big deal a few days and some FM fire stop material.

Running the draft curtain perpendicular to the bar joist is hellish to think about. I have 300' of water curtains and with bar joists 5'-0" on center imagine the fire stopping between every joists with the diagonal joists. Lots of metal cutting and joining.

Since the closest plastic is 50' from the solid beam, and everything for the 50' between the draft curtain to the plastic storage being a Class III commodity why would I need an aisle? Yeah, I am going to need an aisle because I am told to have one so if I have to have an aisle how wide would it be centered under the curtain?

I don't know about the rest of you but I've been designing systems for nearly 50 years now and this is only the second time I have ever had to deal with draft curtains the first time being decades ago so I guess I am new at this.

 

[cdafd]

I am thinking per figure 1 you need 7.5 feet from a curtain

I thought you were trying to separate standard from qr???


I can't find the requirement for baffles to separate the older SR and newer QR storage sprinklers and I know the baffle requirement details HAS to be somewhere.

I do not have access to fm.

What are all the requirements for the separation

 

[SprinklerDesigner2]

It's free and you can get all your FM data sheets here https://www.fm.com/resources/fm-data-sheets

You simply put it who you are with an email and they will NEVER spam you. I've used them for 20 years.

The existing system was installed maybe 35 years ago as a grid with K=8.0 standard response 286 uprights.

Today FM wants to separate the plastic products, actually product packaging material, from the Class III products which is why the QR ESFR (FM calls them Storage Sprinklers) are being installed.

I am thinking it is a 15' aisle as well but I need to make darn sure as this is an FM project.

For what it is worth we can use FM Global Data Sheets and it says so in NFPA #13 Section 1.5 often called the Equivalency Clause.

1.5 Equivalency.

Nothing in this standard is intended to prevent the use of systems, methods, or devices of equivalent or superior quality, strength, fire resistance, effectiveness, durability, and safety over those prescribed by this standard.

Section 1.5 provides the user with an option to submit documentation that the proposed alternative or

Snip

The only thing we can't do with the clause is skip back and forth... you use all of NFPA standards or all FM Global.

 

[cdafd]

So the draft curtain is required between standard and quick response?

Is that correct ?

 

[SprinklerDesigner2]

Yes, very common but the one thing I am not fully informed on is the FM Global requirement for a aisle.

 

[cdafd]

Interesting in 8-9 do not see mention of aisles except for dry systems?

 

[cdafd]

It looks like if you are installing draft curtains per 1-10, to separate standard and qr,,, you have to provide the aisles per 1-10.

 

[UFT12]

Yes, very common but the one thing I am not fully informed on is the FM Global requirement for a aisle.

See 2.5.1.2.5 of FMDS 2-0.

2.5.1.2.5 Ceiling level sprinklers with different RTI ratings can be installed in the same area if:

A. A minimum 2 ft (0.6 m) deep solid noncombustible draft curtain is installed to separate the area protected
by quick-response sprinklers from the area protected by standard-response sprinklers, and

B. A minimum 7-1/2 ft (2.3 m) wide space, measured away from the draft curtain, clear of combustibles
is provided on the side of the draft curtain protected by standard-response sprinklers.