What Rules Apply to Carpet, Mattress and Furniture Storage?

Upholstered furniture and mattresses reach sprinkler requirements sooner than other stored goods because the International Building Code (IBC) gives them their own, smaller thresholds. Under the 2021 IBC, sprinklers are required throughout a Group F-1 or Group S-1 fire area once more than 2,500 sq ft is used to make or store these goods, and throughout a Group M fire area once more than 5,000 sq ft is used to display and sell them, against 12,000 sq ft for most other goods (Sections 903.2.4.3, 903.2.9.4 and 903.2.7.2). The reason is foam: the National Fire Protection Association (NFPA) 13 sprinkler standard and the International Fire Code (IFC) classify foam mattresses and foam-cushioned furniture as expanded Group A plastics, while NFPA 13 lists rolled carpet as outside its protection scope, with no design criteria.

That classification carries into the sprinkler design and the storage rules. Once a building crosses a threshold, the sprinklers have to be designed for plastics rather than ordinary combustibles, and storage of these goods above 6 ft can become high-piled storage under IFC Chapter 32. This article sets out the thresholds, how they are measured, the exceptions, how the goods classify and what the design has to carry in New York, New Jersey, Pennsylvania, Maryland and Delaware.

What Are the Sprinkler Thresholds for Furniture and Mattresses?

The IBC places the furniture and mattress triggers inside the sprinkler requirements for each occupancy group, and the number depends on what the building does with the goods. Making or storing upholstered furniture and mattresses carries the tightest limit. Selling them carries a looser one, because a showroom floor holds less fuel per square foot than a stockroom. The table lists each threshold as it reads in the 2021 IBC and in the 2022 NYC Building Code.

Figure 1: Sprinkler Triggers for Furniture and Mattresses by Occupancy

1. 12,000sq ft fire area, Groups F-1, M and S-1 with other goods2021 IBC Sections 903.2.4, 903.2.7 and 903.2.9, item 1
2. 5,000sq ft used to display and sell upholstered furniture or mattresses (Group M)2021 IBC Section 903.2.7.2
3. 2,500sq ft used to store upholstered furniture or mattresses (Group S-1)2021 IBC Section 903.2.9.4, self-storage exception
4. 2,500sq ft used to manufacture upholstered furniture or mattresses (Group F-1)2021 IBC Section 903.2.4.3

How Are the Furniture and Mattress Thresholds Measured?

Under the 2021 and 2024 IBC, the furniture and mattress thresholds measure the floor area used for the goods inside a fire area, and the sprinklers then go throughout that fire area. IBC Chapter 2 defines a fire area as the floor area enclosed and bounded by fire walls, fire barriers, exterior walls or horizontal assemblies, so a building with no rated separations is one fire area. The code does not say how to draw the line around the area used for the goods. Plan reviewers commonly take the whole storage zone or sales floor given over to them, aisles included, rather than the footprint of the product alone.

Each occupancy group is tested on its own use. A store with a 4,500 sq ft showroom stays under the 5,000 sq ft Group M trigger, but a 3,000 sq ft Group S-1 stockroom of sofas and mattresses behind it passes 2,500 sq ft, and sprinklers are then required throughout the fire area, which includes the showroom when no fire barrier separates the two. IBC Section 311.2 lists furniture, upholstery and mattresses among the Group S-1 storage uses, so a dedicated furniture or mattress warehouse is Group S-1 from the start.

The older format still applies in two places. In the 2018 IBC, which Kent County and Wilmington in Delaware still enforce, and in the 2022 NYC Building Code, the same thresholds sit as numbered items in Sections 903.2.4, 903.2.7 and 903.2.9, which count the occupancy rather than a fire area and require sprinklers throughout the building. Fire barriers do not reset that count, and under the 2018 IBC only a fire wall that creates a separate building does. In NYC even a fire wall rarely helps, because Section 903.2.9 item 2 sprinklers any building over 1,000 sq ft used mainly for Group S-1 storage and Section 903.2.9.1 sprinklers any Group S-1 fire area over 500 sq ft.

Which Exceptions and Alternatives Apply?

The only written exception to the furniture and mattress triggers is for self-service storage. Under 2021 IBC Section 903.2.9.4, a self-storage facility no more than one story above grade plane, where every storage space opens directly to the exterior, does not have to count tenant furniture and mattresses against the 2,500 sq ft limit. The 2022 NYC Building Code and the 2018 IBC carry no such exception.

Fire barriers are the main design alternative under the 2021 and 2024 IBC. A furniture warehouse can be divided so that no fire area holds more than 2,500 sq ft of furniture or mattress storage, with fire barriers rated 3 hours between Group S-1 or Group F-1 fire areas and 2 hours between Group M fire areas (IBC Table 707.3.10). The walls have to run continuously, carry rated doors and stay in place as the business changes, so a sprinkler system usually wins the comparison once the building approaches the 12,000 sq ft fire area limit anyway.

Rolled carpet sits outside these triggers. The IBC names only upholstered furniture and mattresses, so outside NYC a carpet warehouse is tested against the general 12,000 sq ft Group S-1 fire area limit; the 2022 NYC Building Code sprinklers any Group S-1 fire area over 500 sq ft (Section 903.2.9.1). Carpet comes back in through storage height: rolls stored above 12 ft are high-piled storage under IFC Chapter 32, and NFPA 13 gives rolled carpet no design criteria.

How Does NFPA 13 Classify Furniture, Mattresses and Carpet?

NFPA 13 classifies stored goods in Chapter 20, from Class I through Class IV and up to the Group A plastics, and its annex lists examples of common products. The 2021 IFC follows the same examples in Table 3203.8. Both put foam at the top: finished foam mattresses, furniture and bedding with foam cushioning, and foam pillows are Group A expanded plastics, the most demanding of the common storage classes.

Classes paraphrased from 2021 IFC Table 3203.8, which follows the NFPA 13 annex examples. The AHJ accepts the class used for design.

The frame does not lower the class. IFC Section 3203.9.1 bars the mixed-commodity figures from being used to reduce a class the table assigns, so a wood-frame sofa with foam cushions stays Group A expanded even though most of its weight is wood. NFPA 13 handles loads that really are mixed through its limits on Group A plastics within Class I to IV goods, and DGA’s guide to how mixed commodities are classified explains those percentages for a warehouse that holds both.

Packaging is the second decision. A mattress in a plastic bag or a sofa wrapped in stretch film is exposed expanded plastic, the hardest arrangement in NFPA 13 to protect from the ceiling, while the same item in a closed corrugated carton is cartoned. DGA’s article on why cartoned and exposed plastics are protected differently sets out that difference, and the guide to commodity classification and Group A plastics under NFPA 13 covers the full class system.

Figure 2: Foam Mattress vs Cartoned Wood-Frame Sofa

Foam mattress in a plastic bag

• Product: finished foam mattress
• Class: Group A expanded plastic
• Packaging: film only, so exposed
• Design: fewest ceiling-only options; racks often need in-rack sprinklers
• High-piled storage above 6 ft where the fire code official requires it

Wood-frame sofa in a corrugated carton

• Product: wood frame with foam seat and back cushions
• Class: Group A expanded plastic; the foam governs, not the frame
• Packaging: closed carton, so cartoned
• Design: more ceiling-only options than exposed foam, still a plastics design
• Without foam or plastic covering, the same wood piece is Class III

Rolled broadloom carpet is a different case. NFPA 13 (2022) Table A.20.4(a) lists carpet rolls as outside the scope of its protection criteria, so the standard gives them no commodity class and no design. The NFPA 13 storage chapters give rubber tires and roll paper their own design criteria but not rolled carpet, so long rolls in cantilever or carpet racks need a design basis the AHJ accepts, such as insurer criteria or fire test data.

What Applies Once the Threshold Is Crossed?

A triggered fire area needs an NFPA 13 system under IBC Section 903.3.1.1, and the design has to match the goods rather than the occupancy label. A furniture showroom with floor displays and nothing stacked high is often designed as an ordinary hazard occupancy, but the stockroom and warehouse behind it are storage. NFPA 13 allows low piles to be treated as miscellaneous storage, with lower height limits for Group A plastics than for Class I to IV goods, and above those limits the design moves to the storage chapters.

In the storage chapters, foam goods drive the design. Expanded Group A plastics need higher densities and larger design areas under control mode density/area (CMDA) sprinklers in NFPA 13 Chapter 21, or control mode specific application (CMSA) and early suppression fast response (ESFR) sprinklers within the listed limits of Chapters 22 and 23. Exposed expanded plastics have the fewest ceiling-only options and often add in-rack sprinklers under Chapter 25. The higher demand frequently decides whether the water main can serve the system without a fire pump.

Height brings in the fire code. The IFC Chapter 2 definition makes Group A plastics and other high-hazard commodities high-piled combustible storage above 6 ft where the fire code official requires it, half the 12 ft line for ordinary goods, and furniture and mattress warehouses commonly rack stock well above that. Once the designated area passes 500 sq ft, the owner needs an operational permit (Section 105.5 of the 2021 and 2024 IFC; Section 105.6 of the 2018 IFC) and a storage plan under Section 3201.3. Above 2,500 sq ft of high-hazard storage, IFC Table 3206.2 adds sprinklers designed for the storage, fire department access doors and smoke and heat removal.

Furniture and mattress stores that rack stock on the sales floor also pick up the retail aisle and public-area rules, which DGA’s article on fire code rules for storage in big-box stores covers. Owners of retail and shopping center properties usually meet these thresholds at a tenant change, when a mattress retailer or furniture outlet replaces a lower-hazard tenant and the existing sprinkler design no longer matches the stock.

DGA classifies furniture, mattress and carpet storage and checks sprinkler triggers and designs for stores, warehouses and plants across New York, New Jersey, Pennsylvania, Maryland and Delaware. Project briefs get confirmation and preliminary code feedback within one business day. See where DGA works →

How Do NY, NJ, PA, MD and DE Apply the Furniture and Mattress Triggers?

The thresholds come from the building code each jurisdiction adopted, and the sprinkler design follows the NFPA 13 edition that code references. The table shows only what changes for furniture, mattress and carpet storage, as of October 2026.

Editions as listed in DGA’s Fire Code Cheat Sheet for NY, NJ, PA, MD and DE. Local amendments are not shown.

Frequently Asked Questions

This article is general information, not a code determination for any project. Code editions, local amendments and reviewer practice change; confirm the adopted code and the authority having jurisdiction before design.