ESFR and In-Rack Fire Protection for Freezers and High-Bay Warehouses in 2026: What NFPA 13 Requires, What FM Demands, and What It Costs
Cold Storage · Fire Protection · Updated August 2026
ESFR and In-Rack Fire Protection for Freezers and High-Bay Warehouses in 2026: What NFPA 13 Requires, What FM Demands, and What It Costs
Two half million square foot cold storage facilities have burned for a week or longer in the last two years. Here is what actually governs sprinkler design in a freezer, why the insurer's rule book costs more than the code, and the four decisions that set your clear height before you draw a rack.
The Short Answer
Budget $5 to $10 per square foot, or 3 to 5 percent of total project cost, for fire protection on a typical cold storage building, and press toward 5 to 8 percent on a tall FM underwritten freezer. The governing constraint is not the code. It is that every conventional ESFR sprinkler from K-14.0 through K-28.0 is listed for wet pipe only, so a freezer needs a box in a box, the new dry type ESFR-25, or an FM Approved refrigerated area system. And FM's water delivery time limits practically cap each system at 10,000 to 12,000 square feet, which is why a 300,000 square foot FM insured freezer ends up with 25 to 30 separate sprinkler systems instead of eight.
Key Takeaways
- Standard ESFR heads are wet pipe only. Every manufacturer data sheet says so under both UL and FM. You cannot hang a conventional ESFR on a double interlock preaction system.
- The Tyco ESFR-25 Dry-Type, released October 2024, is K-25.2, FM Approved to 50 foot ceilings, and rated to minus 60 F. It is the first real ceiling only dry ESFR for freezers.
- NFPA 13's 45 foot ceiling limit is not physics. It is the height of the FM test facility roof. FM DS 8-9 allows ceiling only to 50 feet, and to 55 feet with K-28.0 at 80 psi.
- Sprinklers eat 4.2 to 4.5 feet of dead height above your top pallet before you count panel thickness, plenum, or structure. Real world top of rack to underside of deck runs 7 to 10 feet.
- NFPA 13-2025 prohibited gridded dry systems. The classic way to shrink freezer pipe volume is gone.
- Listed antifreeze costs about $84 per gallon. Filling a 500 gallon system is roughly $42,000 in product. A nitrogen generator on the same system is about $13,000 turnkey.
- FM requires 8 foot minimum aisles where NFPA 13-2025 now allows 3.5 feet. That is rack positions and pallet revenue, not just a drawing note.
What This Covers
- Which NFPA 13 edition actually applies to your project
- What changed in 2025 that costs money
- Why wet ESFR does not work below freezing
- The K factor and ceiling height envelope
- When in-rack sprinklers become mandatory
- FM versus NFPA, and why FM costs more and sometimes saves more
- How sprinkler design sets your clear height and your IMP quantity
- What the package costs in 2026
- Panel cores: FM 4880, NFPA 285, and the three traps
- What these fires actually cost
- Frequently asked questions
Which Edition Actually Applies
The current published edition is NFPA 13-2025. That is not what most authorities having jurisdiction enforce.
The applicable edition is whatever your adopting statute names. The historical pattern is that the 2021 IBC references NFPA 13-2019, and the 2024 IBC references NFPA 13-2022. So a nationwide contractor in 2026 should expect to encounter NFPA 13-2019 in IBC 2021 states, NFPA 13-2022 in IBC 2024 states, and California running its own cycle on the 2025 California Fire Code.
One useful change in the 2025 edition: Chapter 1 now states that where a newer edition is published, it should be permitted to be used in its entirety. That is an explicit fix for edition lag. You can propose 2025 criteria wholesale to an AHJ sitting on a 2019 or 2022 adoption. What you cannot do is cherry pick the parts you like.
The Fork That Matters More Than The Edition
If the building is FM insured, FM data sheets govern, not NFPA 13, whichever edition the state adopted. A building can be fully NFPA 13 compliant and still be uninsurable at highly protected risk terms because the panels are not FM Approved, the systems exceed FM's water delivery times, or the aisle geometry does not meet DS 8-9. Find out which world you are in before schematic design, not at permit review.
What Changed In NFPA 13-2025
Five changes have real cost consequences for cold storage and high bay work, and one gives money back.
01
Gridded dry systems are prohibited
Section 8.2.1. Field experience showed unacceptable water delivery delay. Loop and grid was the classic way to shrink freezer pipe volume. It is gone, which means more systems or more pipe.
02
Storage over a 2 in 12 slope is finally permitted
Section 20.9 opens six compliance paths above 2 in 12. The clean one for unobstructed construction at 4 in 12 or less carries a 50 percent design area increase, which turns 12 ESFR sprinklers into 18: five on each of the three most demanding branch lines plus three on the next.
03
Deflectors in storage must be parallel to the floor
Section 9.5.4.3. Non storage occupancies keep the option to follow ceiling slope. Storage does not. This lands directly on sloped roof freezers and on IMP ceilings hung dead flat under a sloped deck.
04
Supplemental sprinklers under obstructions are now formalized
A supplemental sprinkler is defined as one installed below an obstruction, with new definitions for non flat and non solid obstructions. ESFR and CMSA supplemental sprinklers get mandated reduced spacing and water shields. In a freezer the obstructions in question are your evaporator coils, defrost lines, and ceiling hung fan units. Expect more heads and much more coordination.
05
The Owner's Certificate is now the Basis of Design
Section 4.2. The owner must submit a storage plan, provide water supply data, and take responsibility for the seismic determination. This is a contract risk item. Push it to the owner in writing before you price the job, because storage classification drives everything downstream and the party who declares it owns it.
06
The C factor rises from 100 to 120
Section 28.3.4.8.1, for dry systems with nitrogen, dry and preaction with vapor corrosion inhibitors, and vacuum systems. This is a genuine hydraulic gift in freezers: roughly 20 percent less friction loss in the calculation, which can shrink pipe or drop a pump stage.
Why Wet ESFR Does Not Work Below Freezing
Water freezes, expansion cracks pipe and fittings, and ice plugs form preferentially in the feed mains where pipe crosses from heated space into the freezer, typically extending 10 to 15 feet inward. Even in a nominally dry system, residual water and humid compressor air produce the same plugs in the same place.
So the freezer gets a dry system. Which creates the second problem.
Dry Pipe Overshoot And The 30 Percent Penalty
With air in the pipe, the first sprinkler to open discharges air, not water, for tens of seconds. During that lag the fire keeps growing, and more sprinklers open than the wet pipe design anticipated. The ones that opened first may already be past the fire's edge.
NFPA 13 compensates by increasing the design area 30 percent for dry pipe and double interlock preaction systems, and in storage occupancies that increase applies to all preaction types, including single interlock. A 1,500 square foot design area becomes 1,950. The handbook rationale is blunt: with the rapid fire growth rate associated with storage occupancies, any delay results in additional sprinklers opening.
A common piece of freezer folklore says the dry system penalty is 25 percent. It is not. The verifiable NFPA 13 dry and preaction design area increase is 30 percent. The only 25 percent figure in the literature is a design area deduction permitted for high temperature rated sprinklers, which is the opposite sign. If a bid tab shows 25 percent, ask what edition and section it came from.
Water Delivery Time Is The Real Cost Driver
This is the number that sets how many systems your building has, and it is where FM and NFPA diverge hardest.
| Rule set | Delivery requirement | Practical system size | Consequence at 300,000 ft² |
|---|---|---|---|
| NFPA 13, under 500 gal | No delivery time requirement, no QOD required | Volume limited | Fewest systems |
| NFPA 13, under 750 gal with listed QOD | No delivery time requirement | Volume limited | Moderate |
| NFPA 13, over 750 gal | Calculate with listed software, per hazard table | Larger systems possible | Roughly 8 to 12 systems |
| NFPA 13 double interlock preaction | 60 seconds to the system test connection | Volume and calc driven | Similar |
| FM DS 2-0 §2.2.1.11.1 | 60 s at one sprinkler, 50 s at two, 40 s at four on unobstructed storage ceilings | 10,000 to 12,000 ft² each | 25 to 30 systems |
| FM DS 8-29 | Water to both ceiling and in-rack within one minute of valve trip, verified by acceptance test | Same | Same, plus test scope |
One more FM constraint with teeth: DS 8-29 limits dry pipe systems protecting plastic insulation to 500 gallons. On a foam cored freezer, that constraint stacked on top of the 10,000 to 12,000 square foot practical limit is what actually drives the system count.
Air Pressure And Accelerators
There is a persistent belief that lower air pressure means faster water delivery. Johnson Controls ran twelve simulations on a 1,430 gallon system at 50, 80, and 120 psi static. Higher air pressure valves tripped and delivered faster in twelve out of twelve runs. Separately, adding an electronic accelerator took a DPV-1 from eight of twelve passing to twelve of twelve passing on NFPA 13 delivery time.
Practical takeaway: budget for accelerators on every freezer system. It is cheap insurance against a failed acceptance test at the worst possible moment in the schedule.
The K Factor And Ceiling Height Envelope
These are outer listing limits, and they are commodity dependent. Your actual envelope depends on what is in the racks.
| K factor | Max storage height | Max ceiling height | Min pressure | System type |
|---|---|---|---|---|
| K-14.0 | 40 ft | 45 ft | Per NFPA 13 / FM 8-9 | Wet only |
| K-16.8 | 40 ft | 45 ft | Per NFPA 13 / FM 8-9 | Wet only |
| K-22.4 | ~40 ft | ~45 ft | FM demands lower than NFPA below 35 ft | Wet |
| K-25.2 | 40 ft | 45 ft standard, 48 ft with special UL listing | 50 psi | Wet |
| K-28.0 | 43 ft | 48 ft | 35 psi | Wet |
| Tyco ESFR-25 Dry-Type, K-25.2 | Per listing | 50 ft, rated to minus 60 F | Per listing | Dry, FM Approved |
| K-33.6 / K-34 performance based | 55 ft storage | 55 ft | FM approved, performance based | Preaction |
The 45 Foot Wall
Why NFPA 13 Stops At 45 Feet And FM Does Not
Ceiling only protection limits by rule set. Every foot above the limit either buys in-rack sprinklers or a different rule book.
NFPA 13
45 ft
ceiling, general limit
The limit exists because the FM test facility roof was at 46 ft. No full scale test data above it.
UL Special Listing
48 ft
ceiling
K-25.2 at 45 to 50 psi, or K-28.0 at 35 psi with 43 ft storage.
FM DS 8-9
50 ft
ceiling, 12 heads
K-22.4, K-25.2, or K-28.0 quick response.
FM, K-28.0 only
55 ft
ceiling, 9 heads at 80 psi
Or FM Approved performance based systems to 55 ft of storage.
Terrapin Construction Group, compiled from NFPA 13, FM DS 8-9, manufacturer listings, and Risk Logic, August 2026.
When In-Rack Sprinklers Become Mandatory
In-rack automatic sprinklers stop being optional when any one of these is true.
- Storage or ceiling height exceeds the ceiling only table for your commodity. Anything above 45 or 48 feet under NFPA 13 without a special listing.
- Solid shelf racks. NFPA 13 does not permit ESFR over solid shelf rack storage without in-rack. Solid shelving means shelf area over 20 square feet and less than 50 percent open.
- Open top containers. Ceiling only ESFR is not permitted over open top containers above the lowest rack level, because the containers collect and trap discharge water instead of passing it down through the array. Mitigations are wire mesh in the container bottom, slotted sides, or fixed lids.
- Exposed uncartoned expanded Group A plastics. Requires K-25.2 with solid vertical barriers and wire mesh shelving, or in-rack.
- K-14.0 and K-16.8 ESFR at a 40 foot ceiling over rack storage. The listing itself requires in-rack.
- Slope over 2 in 12 under the NFPA 13-2025 §20.9 in-rack compliance path.
- FM insured and exceeding the DS 8-9 ceiling only tables for your commodity and height.
Two Things You Cannot Have In An ESFR Building
Draft curtains are forbidden anywhere in an ESFR protected facility. NFPA 13 §20.6.5.3. The empirical basis is NISTIR 6196-1, which found that draft curtains roughly doubled the number of sprinklers that activated, and that curtains near the ignition source disrupted spray patterns and increased fire spread.
Smoke and heat vents must be manual or use a high temperature standard response element. Same NIST study: sprinkler spray cooling frequently prevents automatic vents from operating at all, and vents that opened early over the fire cut sprinkler activations by roughly half. The same study found that a one minute delay in second sprinkler activation quadrupled total activations, which is the clearest single justification for taking dry system delivery time seriously.
Storage Classification Is Where Projects Get Repriced
NFPA 13 runs Class I through Class IV plus Group A, B, and C plastics, with modifiers for cartoned versus exposed, expanded versus unexpanded, and encapsulation. Encapsulation, meaning a plastic sheet completely enclosing the sides and top of a pallet load, raises demand because water cannot reach the commodity and burning plastic runs down the load.
Here is the cold storage reality. Frozen product in corrugated on plastic pallets, stretch wrapped, is routinely Class III to Class IV with encapsulation, and it climbs toward cartoned unexpanded Group A plastic wherever plastic pallets, plastic totes, or bagged and filmed product dominate. Interleaved plastic pallets are a very common reason a building sold as a Class III facility is actually underwritten as Group A.
FM classifies differently again, using explicit 5, 20, and 40 percent plastic content thresholds and its own CUP, CEP, UUP, and UEP buckets. A commodity that reads Class IV under NFPA 13 can land in FM's CUP bucket with substantially higher demand. Get the storage plan nailed down at the Basis of Design stage, in writing, from the owner.
How Sprinklers Set Your Clear Height And Your IMP Quantity
This is the coupling most owners miss, and it is the reason we treat fire protection as an envelope decision rather than a trade decision on cold storage projects.
Stack up the dead height above your top pallet for a ceiling only ESFR scheme:
| Element | Dimension | Why |
|---|---|---|
| Deflector to top of storage | 36 in. minimum | NFPA 13, non negotiable |
| Deflector below ceiling, K-14.0 and K-16.8 pendent | up to 14 in. | Listing requirement |
| Deflector below ceiling, K-22.4 and larger pendent | up to 18 in. | Listing requirement |
| Subtotal, structurally dead height | 50 to 54 in. (4.2 to 4.5 ft) | Before any other allowance |
| IMP ceiling panel | 5 to 8 in. typical for freezer | Thermal requirement |
| Ceiling plenum for hangers and refrigeration piping | Project specific | Coordination |
| Dry system pipe pitch | 0.5 in. per 10 ft | A 200 ft cross main falls 10 in. across the building |
| Structural depth of joists and girders | Project specific | Span and load |
| Typical top of rack to underside of deck | 7 to 10 ft | Real world |
That last line is the trade. Going taller with a K-28.0 or dry type ESFR-25 scheme lets you avoid in-rack sprinklers entirely, but you pay for it in perimeter panel, steel, and refrigeration tonnage. Accepting in-rack lets you hold a lower clear height, but you buy in-rack piping, forklift impact exposure, guards, water shields, separate risers and valves, and a rack layout frozen for the life of the building.
There is no universally right answer. There is only running both schemes through a real cost model before the steel is ordered, which is exactly the work we do in preconstruction.
Four Ways To Protect A Freezer
There Is No Conventional ESFR Option
Every standard ESFR sprinkler from K-14.0 to K-28.0 is listed wet pipe only under both UL and FM.
Sources: Viking, Reliable, and Tyco product listings; Johnson Controls ESFR-25 Dry-Type release, October 2024; FM DS 8-29.
What The Package Costs In 2026
These are budget level numbers triangulated from multiple 2026 dated sources that broadly agree on magnitude. They are not bid level. Price the actual scope with your fire protection subcontractor.
| Scope | 2026 cost per SF | Notes |
|---|---|---|
| Wet pipe, ordinary hazard warehouse | $1.50 to $3.00 | Class I to III, upright |
| ESFR wet, rack storage | $2.00 to $5.00 | Ambient dry warehouse |
| Dry pipe premium over wet | +20% to +40% | |
| Preaction premium over wet | +40% to +80% | |
| Cold storage, dry pipe with insulated piping | $3.50 to $7.00 | |
| Freezer, dry type or double interlock preaction, ESFR equivalent | $4.50 to $9.00 | TCG derived range, not a single published figure |
| Fire protection package, cold storage GC line item | $5 to $10 per SF, 3% to 5% of project cost | 100,000 SF facility |
| Retrofit, occupied high piled | $4.00 to $10.00 | |
| ESFR heads, installed | ~$180 each |
| Facility size | Sprinkler system | With pump and tank |
|---|---|---|
| Under 5,000 SF | $21,000 to $42,000 | Pump rarely required |
| 25,000 SF | $50,000 to $110,000 | $90,000 to $260,000 |
| 50,000 SF and up, ESFR | $140,000 to $280,000 | $180,000 to $430,000 |
| 200,000 SF, ESFR plus pump | $400,000 to $800,000 | $500,000 to $1,050,000 |
Equipment Line Items That Surprise People
| Item | 2026 cost | Note |
|---|---|---|
| Fire pump, commercial, installed | $25,000 to $150,000 | An electric 750 gpm skid is a different animal from a diesel 2,500 gpm pump house |
| On site water storage tank | $15,000 to $250,000 | Depends heavily on volume, material, and freeze protection |
| Nitrogen generator, equipment, one 500 gal dry system | ~$7,000 | At 40 psi with manual vent |
| Nitrogen generator, equipment, four preaction systems, 1,800 gal | ~$15,000 | At 20 psi with automatic vents |
| Nitrogen generator, turnkey installed, 500 gal system | ~$13,000 | |
| Listed premixed antifreeze | ~$84 per gallon | Plus ~$7/gal labor and disposal, five year replacement cycle |
| 500 gallon antifreeze system fill | ~$42,000 | Product only |
| Typical dry pipe corrosion repair | $1,500 to $2,000 | Per repair |
The Antifreeze Question Is Closed
After a 2010 fire in Truckee, California in which an over concentrated glycol solution ignited on discharge and killed someone, NFPA restricted new systems to listed antifreeze only as of September 12, 2012. All legacy glycol had to be removed or replaced by the September 30, 2022 sunset date.
As of 2026 there is no legal path to a new shop mixed glycol sprinkler system in the United States. Only UL 2901 listed premixed solutions are permitted, protecting to roughly minus 25 F, at about $84 per gallon. The arithmetic kills it for anything warehouse scale: $42,000 of product to fill a 500 gallon system, on a five year replacement cycle, versus roughly $13,000 turnkey for a nitrogen generator on the same system. Antifreeze survives in small walk ins, dock canopies, and isolated ancillary areas. Nowhere else.
Nitrogen Is Not Optional On A Serious Freezer
Sprinkler pipe filled with air corrodes 14 to 20 times faster than pipe filled with nitrogen. Humid compressor air is the primary source of the ice plugs that form in the feed mains 10 to 15 feet inside the freezer wall.
FM DS 2-0 requires nitrogen or an FM Approved gaseous medium, permitting air only through an FM Approved dry air unit with duplex supply lines sized to give up their heat before entering the box. FM DS 8-29 requires the pressure dew point to be 20 F below the nominal freezer temperature. The purity target is 98 percent nitrogen or better, and at that level with two consecutive clean annual inspections, ice plug investigation intervals may be extended to three years.
Then there is the hydraulic payoff already mentioned: NFPA 13-2025 raises the C factor from 100 to 120 for nitrogen inerted systems, which can be worth up to a 30 percent reduction in friction loss against the penalized value.
Panel Cores: FM 4880, NFPA 285, And Three Traps
NFPA 13 does not care what your insulation core is. It only sizes the sprinklers. Your insurer cares enormously, and so does the building code, for different reasons.
| Standard | What it tests | Who requires it |
|---|---|---|
| ASTM E84 / UL 723 | Surface burning of the bare foam core | IBC Chapter 26 interior finish. FM sets no pass/fail limits on E84 results |
| FM 4880 | Class 1 rating of insulated wall and wall/roof/ceiling panels via 25 ft and 50 ft corner tests | FM insured properties. The controlling standard for interior cold store panels |
| FM 4881 | Class 1 exterior wall systems, adds structural wind performance | FM insured exterior walls |
| FM 4882 | Class 1 interior wall and ceiling for smoke sensitive occupancies | FM, food and pharma |
| NFPA 285 | Full exterior wall assembly, fire from interior and exterior simultaneously | IBC §2603.5 for foam plastic in exterior walls of Type I to IV construction |
FM 4880's height tiers matter more than the Class 1 label. Pass the 25 foot corner test and you are approved to 30 feet. Pass both the 25 and 50 foot corner tests and you reach 50 feet. Pass the 50 foot corner test with no ceiling ignition, plus both corner tests, and you get unlimited height. The 50 foot corner test is waived entirely for noncombustible cores meeting ash content of 90 percent or more and heat content of 2.0 kJ/g or less, which is the structural reason mineral wool sails through and foam does not.
The Three Traps
01
FM 4880 and ASTM E84 cannot substitute for NFPA 285
The Metal Construction Association is explicit that those tests cannot be used in lieu of NFPA 285 evaluations, because they lack the simultaneous dual side fire exposure. The 2015 IBC clarified that §2603.9 does not apply to §2603.5. You cannot test your way out of NFPA 285.
02
NFPA 285 tests the assembly, not the panel
Each manufacturer's specific foam formulation must be tested at the maximum contemplated thickness and density. A panel that passed at 4 inches is not automatically compliant at 8 inches.
03
FM Approval is product, thickness, and assembly specific
"FM 4880 Class 1" without a height tier is meaningless. Get the FM Approval Guide listing showing 30 ft, 50 ft, or unlimited for the exact panel, exact thickness, exact facing, and exact joint detail you are buying. We keep listings for the manufacturers we install and covered the landscape in our comparison of US IMP manufacturers.
Treat EPS As Disqualifying On An FM Account
FM DS 8-29 states plainly: do not use dry pipe systems with expanded or extruded polystyrene. Replace the EPS or cover it with a thermal barrier per DS 1-57. Expanded polystyrene is thermoplastic. It melts and drips. Mineral wool cores test at flame spread zero and smoke developed zero and carry wall fire resistance ratings of one, two, and three hours at 4, 6, and 8 inches, but they cost you thermally at roughly R-3.61 per inch. Polyisocyanurate remains the cold storage workhorse on R value per inch and passes NFPA 285 when installed per listed details. The choice is a real engineering trade, not a preference.
What These Fires Actually Cost
Two things have changed in this market. Buildings got much bigger, and the losses got much worse.
Warehouse fires run roughly 1,544 per year across 2020 to 2024 excluding cold storage, with about two deaths and seventeen injuries annually but roughly $200 million in average annual damage. Fewer fires, far costlier ones. The median warehouse in 2022 was 25 percent larger than in 2012, and leasing for 500,000 square foot and larger sites was up 31 percent year over year in 2025.
| Event | Size and date | Outcome |
|---|---|---|
| Boyle Heights, Los Angeles | ~491,000 SF cold storage, ignited June 17, 2026 | Burned seven days, knocked down June 24. Roughly 85 million pounds of frozen food. State of emergency declared June 20 over biohazard and air quality. Cause officially undetermined. A prior fire at the same site in 2024 was extinguished in 48 minutes. |
| Finley, Washington | ~500,000 to 525,000 SF cold storage, ignited April 21, 2024 | Not declared extinguished until June 20, 2024, roughly two months. Partial structural collapse, Level 3 evacuations. Cause undetermined. The operator recognized $107 million in insurance reimbursements. |
| Medline Industries, Tracy, CA | 925,000 SF medical supply, June 2026 | Destroyed |
| Washington state, NFPA documented | Cold storage | $2,500,000. Ignition by cutting torch work on 2.5 to 3 inches of sprayed polyurethane foam with no thermal barrier and no automatic protection |
| Insurer documented refrigerated warehouse losses | 2014 dollars | $87.5 million and $71.2 million, attributed to inadequate ceiling only protection and disabled alarm systems |
The two AXA XL figures are the most useful numbers in this entire article, because they tie a protection scheme directly to a loss magnitude. Inadequate ceiling only protection and disabled alarms produced $87.5 million and $71.2 million in single events. Set against a fire protection package that runs three to eight percent of a project's hard cost, that is not a close call.
Citing the Global Cold Chain Alliance and the Allianz Risk Barometer, fire is a top three risk and the most frequent driver of costly business interruption claims, accounting for more than a third of claims by value. Zurich's framing is the one to take to a board: the trend toward megafacilities is creating scenarios that set the stage for larger, more destructive fires that exceed firefighter abilities.
FM Versus NFPA: Where It Costs More, Where It Pays Back
| Where FM costs more | Where FM pays you back |
|---|---|
| Water delivery of 40 to 60 seconds at one to four sprinklers, forcing system subdivision to 10,000 to 12,000 ft² each | Ceiling only to 50 ft with K-22.4, K-25.2, or K-28.0, and to 55 ft with K-28.0 at 80 psi |
| 8 ft minimum aisles versus NFPA 13-2025's 3.5 ft allowance, a direct loss of rack positions | FM's K-22.4 pressure demands below 35 ft are lower than NFPA 13's, which can mean smaller pipe and a smaller pump |
| FM Approved equipment only, across sprinklers, valves, hangers, and panels | Building taller without in-rack sprinklers, which can be the cheaper path in total |
| Higher water supply volumes and pressures, frequently forcing a tank and pump NFPA 13 alone would not | Access to performance based schemes with no NFPA equivalent |
| More robust seismic bracing in the same seismic design category |
Insurer risk guidance sets the underwriting expectation before you ever quote. AXA XL's refrigerated storage guideline is representative and gives you the checklist an underwriter will run: wet above 40 F, dry from 0 to 40 F, double interlock below 0 F; freezer risers capped at 20,000 square feet versus NFPA 13's 40,000 to limit impairment scope; separate risers and shutoff valves for ceiling versus in-rack; detectors not attached to sprinkler piping; moisture free air via dryer or dry nitrogen; and dry sprinklers tested or replaced on a ten year interval because the service environment is brutal.
The One Piece Of Advice That Saves The Most Money
Get the carrier's risk engineer into design development, not permit review. Three items reprice a cold storage job late: FM system count driven by water delivery time, panel core and FM listing, and aisle width. All three are cheap to fix on paper and brutally expensive to fix after steel is ordered.
Model Both Schemes Before You Buy Steel
Terrapin Construction Group builds cold storage and high bay facilities nationwide, licensed in all 50 states, with more than one million square feet of insulated metal panel installed across 38 states. We run ceiling only against in-rack, and FM against code minimum, as a preconstruction deliverable, so the clear height decision is made with numbers instead of assumptions.
Schedule A 30 Minute Call Get An Instant EstimateFrequently Asked Questions
Can I use ESFR sprinklers in a freezer?
Not with conventional ESFR heads. Every standard ESFR sprinkler from K-14.0 through K-28.0 is UL Listed and FM Approved for wet pipe systems only. You have three real options. First, box in a box, meaning wet ESFR in the heated space above with dry pendents dropping through the insulated ceiling. Second, the Tyco ESFR-25 Dry-Type at K-25.2, FM Approved to 50 foot ceilings and rated to minus 60 F, released in October 2024, which is the first true ceiling only dry ESFR for freezers. Third, an FM Approved refrigerated area system or double interlock preaction with large K storage sprinklers, including performance based schemes that are FM Approved for ceiling only protection to 55 feet.
How tall can I build without in-rack sprinklers?
Under NFPA 13 the general ceiling only limit is 45 feet, extendable to 48 feet with a specific UL listing using K-25.2 at 45 to 50 psi or K-28.0 at 35 psi with 43 foot storage. Under FM DS 8-9 you get 50 feet with K-22.4, K-25.2, or K-28.0 quick response, and 55 feet with K-28.0 only at 80 psi with nine heads. FM Approved performance based systems reach 55 feet of storage. The 45 foot number is not physics. It is the height of the FM test facility roof, so no full scale test data exists above it.
What drives my clear height, the racks or the sprinklers?
Both, and the sprinklers add roughly 4.2 to 4.5 feet you cannot use. NFPA 13 requires a 36 inch minimum clearance between the ESFR deflector and the top of storage, and the deflector must sit within 12 to 18 inches of the ceiling depending on K factor and orientation. Add the IMP ceiling panel, the plenum for hanger rods and refrigeration piping, the half inch per ten foot pitch that dry systems require, and the structural depth, and top of rack to underside of deck commonly runs 7 to 10 feet.
How much does the fire protection package cost on a cold storage building?
Budget $5 to $10 per square foot, or 3 to 5 percent of total project cost, for the fire protection and sprinkler line on a typical 100,000 square foot facility. Within that, cold storage sprinklers run $3.50 to $7.00 per square foot versus $1.50 to $3.00 for a dry ambient warehouse, because dry pipe adds 20 to 40 percent and preaction adds 40 to 80 percent over a wet system. A fire pump adds $25,000 to $150,000 and an on site tank $15,000 to $250,000. On a tall FM underwritten freezer with 20 or more subdivided systems, expect the package to press toward 5 to 8 percent.
Why does my insurer require FM Approved panels when the building code does not?
Because the code regulates life safety and the insurer regulates loss. NFPA 13 does not care what your insulation core is. It only sizes the sprinklers. FM 4880 rates the panel assembly itself in 25 foot and 50 foot corner burns and issues a Class 1 rating at 30 feet, 50 feet, or unlimited height, and FM DS 8-29 requires noncombustible or Class 1 ceiling and roof materials in refrigerated storage while prohibiting dry pipe systems over expanded or extruded polystyrene. Getting FM 4880 Class 1 on a submittal is not enough. You need the height tier for your exact panel, thickness, facing, and joint detail.
Can I still use antifreeze in my sprinkler system?
Practically, no. After the 2010 Truckee incident, NFPA restricted new systems to listed antifreeze only as of September 12, 2012, and all legacy glycol had to be removed or replaced by the September 30, 2022 sunset date. Only UL 2901 listed premixed solutions are permitted, protecting to about minus 25 F, at roughly $84 per gallon. That is about $42,000 just to fill a 500 gallon system, on a five year replacement cycle, versus about $13,000 turnkey for a nitrogen generator on the same system. Antifreeze survives only in small walk ins and isolated ancillary areas.
What is a double interlock preaction system and why do I need one?
It requires two independent events before water enters the pipe: a detection signal, usually from linear heat detection cable rather than spot smoke detectors, and loss of supervisory air or nitrogen from a sprinkler that has actually operated. The point in a freezer is not avoiding water damage. It is preventing trapped residual water from forming ice plugs after a false trip. FM requires an FM Approved refrigerated area system below 20 F for storage, and requires water to reach both ceiling and in-rack sprinklers within one minute of valve trip, verified by acceptance test. The tradeoff is that these systems are markedly more complex and more prone to failure if inspection and testing discipline lapses.
Why do I need so many separate sprinkler systems in my freezer?
Water delivery time. NFPA 13 gives you 60 seconds at the inspector's test connection, with no time requirement at all if the system is under 500 gallons, or under 750 gallons with a listed quick opening device. FM DS 2-0 is far tighter, at 60 seconds with one sprinkler open, 50 with two, and 40 seconds with four sprinklers open on an unobstructed storage ceiling, and FM notes that hitting those times practically limits each system to about 10,000 to 12,000 square feet. On a 300,000 square foot FM insured freezer that is 25 to 30 separate systems, each with its own valve, riser, trim, detection zone, gas supply, and trip test connection. NFPA 13-2025 also prohibited gridded dry systems, removing the old way to shrink pipe volume.
Do I need a nitrogen generator, or is compressed air fine?
Air is the problem. Sprinkler pipe filled with air corrodes 14 to 20 times faster than pipe filled with nitrogen, and humid compressor air is the primary source of the ice plugs that form in the feed mains 10 to 15 feet inside the freezer wall. FM DS 2-0 requires nitrogen or an FM Approved gaseous medium, permitting air only through an FM Approved dry air unit, and FM DS 8-29 requires the pressure dew point to be 20 F below the nominal freezer temperature. There is also a hydraulic payoff, because NFPA 13-2025 raises the C factor from 100 to 120 for nitrogen inerted dry systems, which can shrink pipe sizes or drop a pump stage.
What changed in the 2025 edition of NFPA 13 that will cost me money?
Five things. Gridded dry systems are now prohibited, which forces more pipe or more systems in freezers. Storage occupancies can finally exceed a 2 in 12 ceiling slope, but the unobstructed construction path carries a 50 percent design area increase, turning 12 ESFR sprinklers into 18. Deflectors in storage must be parallel to the floor rather than the roof slope. Supplemental sprinklers under obstructions are now formally defined and regulated with tighter ESFR and CMSA spacing and mandatory water shields, which lands squarely on evaporator coils, defrost piping, and ceiling hung fan units. And the Owner's Certificate is now the Basis of Design, obligating the owner to furnish a storage plan, water supply data, and the seismic determination. The one change that gives money back is the C factor increase from 100 to 120 for nitrogen, VCI, and vacuum dry systems.
Sources And Further Reading
- NFPA TIA 25-2 to NFPA 13-2025, effective September 18, 2024
- Proposed TIA 1782 to NFPA 13-2025, partial reproduction of Table 23.3.1
- NFSA TechNotes, Changes in the 2025 Edition of NFPA 13
- NFSA, Listed Antifreeze and the Sunset Date
- FM Property Loss Prevention Data Sheets portal
- FM technical report to NFPA 13 on ESFR protection of exposed nonexpanded Group A plastics
- FM Data Sheet 2-0, Installation Guidelines for Automatic Sprinklers
- FM Approval Standard 4880, Class 1 Insulated Wall and Wall/Roof/Ceiling Panels
- Reliable Model N28 ESFR bulletin, K-28.0 to 48 ft ceiling
- Reliable Model P25 ESFR bulletin, K-25.2
- Johnson Controls, Tyco ESFR-25 Dry-Type sprinkler release, October 2024
- Tyco Quell and VanQuish performance based cold storage protection
- AXA XL PRC.10.2.11, Refrigerated Storage and Warehousing risk guideline
- NISTIR 6196-1, Sprinkler, Smoke and Heat Vent, Draft Curtain Interaction
- Global Cold Chain Alliance, Cold Facts, Fighting Fire
- Risk Logic, Ceiling Only Sprinkler Designs Above 45 Feet
- Risk Logic, Flue Space Requirements, NFPA 13 versus FM
- Engineered Corrosion Solutions, Listed Antifreeze versus Nitrogen Generator Cost
- ASPE Pipeline, Water Delivery Time in Dry Pipe Fire Protection Systems
- Metal Construction Association, Insulated Metal Panels and NFPA 285
- UL Solutions, Fire Sprinkler Testing and Certification
- IIAR, ANSI/IIAR Standards Interpretations
- ASHRAE Handbook, Refrigeration volume
- LA Public Press investigation of the Boyle Heights cold storage fire, July 2026
- Bisnow, Big Box Warehouse Blazes Highlight Risks of Megafacilities
Terrapin Construction Group is a nationwide design build commercial general contractor headquartered in Denver, Colorado, licensed in all 50 states, and a Procore Certified Contractor. We have installed more than one million square feet of insulated metal panel across 38 states, and we build cold storage, food processing, cannabis, and data center facilities nationwide.
Cost figures are budgetary and current as of August 2026. Code editions, adopted amendments, insurer data sheets, and product listings all change. Confirm the adopted NFPA 13 edition with your authority having jurisdiction and the governing data sheet revision with your carrier before relying on any threshold in this article. Nothing here is a substitute for a licensed fire protection engineer's stamped design.
