When are In-Rack Sprinklers Required?

12/10/2021

I don't deal with storage in fire protection systems - but I have a question regarding different storage arrangements.

When does a system have to have in-rack sprinklers?

Are there always alternative solutions that an owner can use to avoid in-rack sprinklers?

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12 Comments

Pete H

12/10/2021 06:51:37 am

In chapters 16 and 17 (protection of rack storage of class I through class IV commodities, and protection of rack storage of plastic commodities, NFPA 13 2016 edition respectively), there are charts that show you storage arrangements that may require in rack sprinklers depending on storage heights, encapsulation, and aisle width.

There are separate rules for rubber tire or paper storage that might also require in rack sprinklers. Look at the relevant chapters and charts and see if they match your projected storage arrangements, or if you have to modify storage to get away from required in-racks.

Alex

12/10/2021 06:51:48 am

Hi,

This question is far to long to answer on Meyer.

If you are asking the question, I would recommend hiring an FPE to review and complete the design. Any project with storage is extremely though and requires some extensive knowledge in not only design but when you get down to the calculations as well.

NFPA 13 (2016) Chapter 13 through 21 will make reference and describe the requirements of in-racks. The question should be worded "what can I do to NOT require in rack sprinklers" over the question of when they are required!

Alex

Dan Wilder

12/10/2021 07:27:55 am

Without sounding too condescending....when the NFPA charts require them based on commodity, storage height, encapsulation, aisle width, pallet type......

As noted above, it takes a detailed and experienced review to get to that answer and not something to just jump into.

There are several new storage sprinklers/technologies allowing storage to greater heights and higher commodities (electrically activated sprinklers, K25/28/34 ESFR come to mind, Quell has been around but has been amazing in cold storage).

Typically , the alternatives to avoid in-rack protection require some or all of the following: lowering the storage height, changing aisle width, or only allowing specific commodities to be stored in specific areas and/or at specific heights. In all but one project, the owner/warehouse manager/national-regional logistics managers all, emphatically said that there was no way they were going to comply with those reductions. They really didn't care about the in-racks, but wanted full utilization of their space.

Jesse

12/10/2021 08:14:33 am

Not nearly enough time and space to answer this.

The short answer, is that IRAS (in-rack automatic sprinklers) can be avoided in many instances. But in some others, they are inevitable, even with suppression mode sprinklers at the ceiling.

If your project is under the auspices of NFPA 13, Chapters 16-21 are where you need to be. There are really good logic flow charts to determine a design criteria - and remember it all starts with identifying the commodity class.

If its not within the scope of 13, but rather FM the process is similar. I actually have 2 FM projects currently.

Vince Diorio

12/10/2021 08:14:47 am

I do high pile storage design throughout the country. NFPA 13 Chapters 12 forward to 21, IFC Chapter 32, FM many chapters is use everyday along with discussions with the AHJ an the clients insurance company. There are many ways to get the roof fire sprinkler system to handle high pile storage depending on the type of commodity that's being storage. Definitely way to much to type. So many new fire sprinkler heads that are out now for this type of fire protection.

Franck

12/10/2021 08:43:40 am

Almost everything has been said. Too many possible answer to the same question (When does a system have to have in-rack sprinklers?) depending on storage configuration, height, ceiling density, type of sprinkler, etc.
And as indicated, you have to refer to the right chapter in NFPA 13 to find guidance.
For the 2d question (Are there always alternative solutions that an owner can use to avoid in-rack sprinklers?), the answer is NO. There are some configurations and commodities where in-rack sprinklers are mandatory. It is the case, for example, if you have solid shelves in your racks (by the way, having solid shelves in racks is never a good idea from a fire prvention/protection standpoint), or if you store plastic commodities too high.

Sundance

12/10/2021 09:53:00 am

Expanding on Franck’s comment related to solid shelving. This has been a major issue for us and NFPA-13 (2019) really doubles down on how a “solid shelving” condition created by the “placement of loads” with a footprint greater than 20 sf even to the point of putting bare steel pipe on cantilever racks, etc. I see several comments above referencing NFPA-16 and this “solid shelf” requirement is already expressed in that version as well.

One other related item in NFPA-13 (2019), is they now define an allowable depth related to multi-row racks even when maintaining a transverse flue space at 5’ oc max. This can require sprinklers in locations where they were not previously required.

Glenn Berger

12/10/2021 10:34:20 am

Concur with the above comments. I try to avoid in-rack sprinklers at all cost!

Ivonn

12/10/2021 10:37:54 am

Are there always alternative solutions that an owner can use to avoid in-rack sprinklers?

Some design criteria, for example the use of ESFR can avoid the use of in-rack sprinklers if you can tell us more information about the comodity and storage configuration

Also for a tall buildings(55ft) the use of big k-factor ESFR like 28.0 or 33.6 but they have limitations of comodity and storage configurations

sean

12/11/2021 07:59:45 am

A general rule of thumb is a basic heads has much less storage it can protect without in-rack and your allowed more and more as you approach ESFR.

Same for commodity has the hazard increases the greater chance for in-rack sprinklers

Sundance

12/11/2021 10:04:05 am

Related to “solid shelving” whether created with shelf material or by the “placement of loads” >20 sf, once you go over 12’ in height in a Storage Occupancy (there are some special provision under Mercantile Occupancy), to our knowledge, there is no way around In-Racks. This provision is not dependent on the “Roof Level System” type and it does not matter if you have ESFR, K-25, etc.

If someone knows a work-a-round on this, we would love to hear about it.

sean

12/13/2021 08:15:13 pm

this is really interesting. Ill have to look into it as applies to 2021 IBC

When are In-Rack Sprinklers Required?

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