Best Fire Retardant Spray Foam Insulation for Walls and Gaps

#1 · Best Overall

1. BEEST FullStop 240 Kit

• Material Type: Plastic

Best for: Large wall and attic jobs.

Why it ranks #1: Offers up to 240 board feet, ASTM E84 results of FSI 0 and SDI 120, R-8.24 at 2 inches, plus a gun, cleaner, and safety gear.

ASTM E84 testing with a Flame Spread Index of 0 and Smoke Developed Index of 120 gives BEEST FullStop specific Class A surface-burning credentials. The 12-can kit also lists up to 240 board feet of coverage and an R-value of 8.24 at two inches, supporting larger wall and attic insulation work.

The bundle includes a Pro X gun, foam cleaner, glasses, coverall, and gloves alongside the 12 cans, putting application equipment and listed protective items together for the job. Its stated 240-board-foot coverage helps buyers plan a larger area, while the R-value at two-inch thickness provides a reference for thermal insulation. The kit is aimed at spray insulation rather than a small, isolated gap; coverage and performance remain tied to the stated application conditions.

Skip it if you need a smaller insulation kit; BEEST FullStop 120 Board ft 6-pack offers half the listed coverage.

For buyers insulating substantial wall or attic areas, this kit combines documented Class A results, stated thermal value, and application equipment. Its coverage scale is the main fit consideration for contained repairs.

Listed on Amazon as: BEEST FullStop Spray Foam Insulation Kit – 240 Board ft/sq.ft. Fire Rated Spray Insulation Foam for Walls & Attics with Thermal & Soundproofing – Includes 12x Cans, 1 Cleaner, Pro X Gun, Safety Gear

#2

2. Sprayman Spraycoat Kit

• Material Type: Urethane adhesive

Best for: Gun-applied wall insulation.

Why it ranks #2: The title states 240 square feet and R-11.32 at 2 inches; the 12-pack includes an application gun and cleaner for larger insulation jobs.

A stated R-value of 11.32 at two inches gives Sprayman Spraycoat a specific thermal figure for wall and attic insulation planning. Its 240-square-foot kit includes 12 cans, an application gun, and gun cleaner, bringing the core application and maintenance items together for a larger insulation job.

The title identifies closed-cell foam for heat and noise insulation, making the kit relevant when both thermal and sound insulation are goals. A 12-can quantity and stated 240-square-foot coverage help buyers assess the project scale before starting, while the included gun supports controlled application across the listed wall and attic uses. The cleaner is included for gun maintenance after application. The listing does not give a fire-test classification or smoke-development figure to compare against rated alternatives.

Skip it if you require documented ASTM E84 results; BEEST FullStop 240 Board ft kit lists its flame spread and smoke developed indices.

Sprayman suits buyers covering walls or attics who want the stated thermal value, noise insulation, and gun-based kit workflow. Those needing a listed fire-test classification should weigh that missing specification before choosing.

Listed on Amazon as: Sprayman Spraycoat Fire Rated Spray Foam Insulation Kit 240 Sq.Ft – High R-Value (11.32 / 2in) Closed Cell Heat & Noise Insulation for Wall & Attic – Gun, Cleaner & Safety Gear – 27.1 oz, 12 Pack

#3 · Class A Surface Rating

3. BEEST FullStop 120 Kit

• Material Type: Polyurethane foam

Best for: Mid-size thermal insulation jobs.

Why it ranks #3: States up to 120 board feet, ASTM E84 FSI 0 and SDI 120, and R-8.24 at 2 inches in a six-can insulation format.

ASTM E84 results of Flame Spread Index 0 and Smoke Developed Index 120 give BEEST FullStop documented Class A surface-burning performance. This six-can kit lists up to 120 board feet of coverage and an R-value of 8.24 at two inches, offering a defined scale for wall and attic insulation work.

The stated coverage helps scope a mid-size project, while the R-value at two-inch thickness gives buyers a thermal reference for the specified application depth. The expanding polyurethane foam is also listed for sound insulation, so the product serves thermal and acoustic goals in walls or attics. Compared with a larger coverage kit, this 120-board-foot amount suits a more limited area; the supplied listing does not identify included application equipment or safety gear for this six-pack.

Skip it if you need 240 board feet in one kit; BEEST FullStop 240 Board ft kit lists twice this product’s stated coverage.

This six-can FullStop kit suits buyers insulating a defined wall or attic area who want stated coverage, thermal value, and Class A test figures. Check the project scale and application-equipment needs before selecting it.

Listed on Amazon as: BEEST FullStop Fire-Rated Spray Foam Insulation for Walls & Attics – 120 Board ft/sq.ft – High Density Expanding Spray Insulation Foam Sealant for Thermal & Soundproofing – 6 Pack (6×26.8 oz)

#4 · Wide-Area Coverage

4. Kraken Bond Thermafoam

• Material Type: Polyurethane
• Compatible Material: Wood, Metal, Masonry, Drywall
• Form: Spray

Best for: Wide-spray attic insulation.

Why it ranks #4: Its wide-spray format suits hard-to-reach spaces and lists Class A performance, FSI at most 15, SDI at most 40, and R-5.66 per inch.

Wide spray coverage is the defining feature of Kraken Bond Thermafoam, intended to reach attics, wall cavities, California corners, and other difficult spaces. The two 16 oz cans include Smart Nozzles, while Class A fire performance and an R-value of 5.66 per inch connect broad application with stated insulation properties.

The listed flame spread index of 15 or less and smoke developed index of 40 or less provide specific fire-performance figures for buyers comparing insulation options. An R-value of 5.66 per inch gives a thermal reference, and the wide-spray format can help cover larger or harder-to-reach surfaces than a narrow targeted application. Compatibility with wood, metal, masonry, and drywall supports use across the named cavity types; the package contains two cans, a consideration for extensive areas.

Skip it if you need substantially more listed coverage; BEEST FullStop 240 Board ft kit specifies coverage up to 240 board feet.

This Kraken Bond option fits buyers applying insulation into hard-to-reach spaces who value a wide spray and stated fire and R-value figures. For extensive coverage, account for its two-can package when planning the job.

Listed on Amazon as: Kraken Bond Thermafoam Wide Spray Foam Insulation (2x16oz) – Class A Fire Rated Polyurethane Sealant for Attic, Wall Cavities, California Corners & Hard-to-Reach Spaces | Includes Smart Nozzle

#5 · Largest Fire-Block Pack

5. Akfix 840P Fire Block

• Material Type: spray foam
• Compatible Material: Concrete, Stone, Wood, Steel, Metal, Pvc…
• Form: Spray

Best for: Gun-applied fireblock sealing.

Why it ranks #5: The 12-can, 25.3-ounce pack is a self-extinguishable fire-block foam; it adheres to listed building materials and can be painted after curing.

The Akfix 840P package combines twelve 25.3 oz cans with a gun and two cleaners, supporting repeated fireblock sealing work with a consistent application setup. Its self-extinguishable polyurethane foam is intended for fireblock-required areas and can be painted after curing, useful when a finished surface matters.

Compatibility is listed for concrete, stone, wood, steel, metal, PVC, and drywall, offering flexibility around window and door openings and other construction materials. The expanding foam provides filling and insulation, while the included gun and cleaners support application and subsequent equipment maintenance across multiple cans. Its paintable-after-curing property can help the sealed area blend into a finished space. The large multi-can kit is better suited to repeated work than a small, isolated repair.

Skip it if you only need a small two-can quantity; Akfix 840 Fire Block Spray Foam is listed as a two-pack.

For buyers handling repeated window, door, or other fireblock sealing, the 12-can kit pairs broad material compatibility with gun and cleaner supplies. Its scale may exceed what a single small repair needs.

Listed on Amazon as: Akfix 840P Fire Block Spray Foam (12×25.3 Oz.) – Orange Color Fire Retardant Polyurethane Expanding Foam Sealing on Window and Door, Paintable | Gun Use, Gun&2Cleaner Included | 25.3 Oz. 12 Pack

#6

6. Kraken Bond Extreme Foam

• Material Type: Polyurethane Foam
• Compatible Material: Wood, Metal, Glass, Plastic, Concrete, Brick
• Form: Foam

Best for: Certified gap-filling projects.

Why it ranks #6: This two-pack of 24-ounce fire-block foam lists ASTM E84-20 and UL Classified certification, with high expansion for filling gaps and penetrations.

ASTM E84-20 and UL Classified certification distinguish Kraken Bond Extreme Orange Fire Block Foam for safety-focused construction and repair. Its high-expansion polyurethane comes in two 24 oz cans with straw application, enabling buyers to fill and seal gaps, joints, cavities, and wall penetrations across a range of listed materials.

The foam’s stated compatibility with wood, metal, glass, plastic, concrete, and brick gives it flexibility across common repair surfaces. High expansion and strong adhesion help cover irregular gaps and cavities, while the straw-use format supports direct application without a listed gun kit. Two 24 oz cans provide material for more than one sealing task, though this listing does not provide an R-value or a quantified coverage figure for planning insulation depth or area.

Skip it if you need a stated R-value and wide coverage for attic cavities; Kraken Bond Thermafoam lists R-5.66 per inch and wide spray coverage.

Choose it for certified gap sealing across varied construction materials when straw application fits the task. Buyers planning thermal insulation by area or R-value should note those figures are not supplied in this listing.

Listed on Amazon as: Kraken Bond Extreme Orange Fire Block Foam – (2x24oz) Fire Rated Polyurethane Spray for Gap Filling, Sealing on Windows, Walls, Joints & Pipes, Straw Use High Expansion Fire Proof Foam – 2 Pack

#7

7. DAP FireBreak Foam

• Material Type: Foam, Polyurethane
• Compatible Material: Multiple Materials, Including Metals…
• Form: Foam

Best for: Service-penetration sealing.

Why it ranks #7: A Class 1 fire-retardant, self-extinguishing sealant intended for service penetrations, joints, and gaps in residential and commercial applications.

DAP FireBreak’s self-extinguishing Class 1 formula works by eliminating oxygen flow through service penetrations, targeting places where fire can spread quickly. The 12 oz foam sealant also fills gaps and cracks, letting buyers address fireblocking and drafts around HVAC, plumbing, and electrical runs with one product.

The stated applications extend beyond service penetrations to joints, through penetrations, partitions, stud walls, stair stringers, soffits, and drop ceilings, making it relevant for varied construction sealing work. Its foam fills cracks and seals drafts, while compatibility with metals, plastics, and other common construction materials supports use around mixed-material services. The single-can format suits contained tasks; the listed 12 oz capacity is a practical boundary for larger projects requiring more material.

Skip it if you need broad wall or attic insulation coverage; BEEST FullStop 240 Board ft kit includes 12 cans and an applicator gun.

A practical pick for buyers sealing service penetrations, joints, and construction gaps where its Class 1, self-extinguishing claim is relevant. The 12 oz can suits contained work better than a broad insulation project.

Listed on Amazon as: DAP FireBreak Flame Resistant Foam Sealant, Orange, 12 oz (7565010012)

#8

8. 3M Fire Block Foam

• Material Type: Polyurethane

Best for: Workplace fireblock repairs.

Why it ranks #8: Tested to ASTM E84 modified as a Type V residential fireblock, it expands up to 200% and is heat resistant up to 240°F; labeled for occupational use.

ASTM E84 (modified) Type V Residential Fireblock testing gives the 3M FB-Foam a clearly stated performance basis for sealing openings in residential and commercial construction. Its ready-to-use polyurethane expands up to 200% after dispensing, helping fill gaps while its draftstop function helps reduce air infiltration.

The 12 fl oz can is ready to use without mixing, which keeps a small sealing task straightforward. Expansion up to 200% helps the foam fill openings, while the stated heat resistance up to 240°F and durable polyurethane support use where heat resistance matters. It is described for fire resistance and draft prevention, and the product description also identifies sealing, filling, insulating, and bonding uses. Its industrial and occupational-use restriction makes the intended user an important part of the decision.

Skip it if you need a product for consumer sale; DAP FireBreak is listed for commercial and residential applications.

For trained workplace users sealing residential or commercial openings, this 3M foam combines tested fireblocking, expansion, and draft reduction in a ready-to-use can. Its industrial and occupational-use restriction is the key boundary.

Listed on Amazon as: 3M Fire Block Foam FB-Foam, Orange Color, 12 fl oz Can

#9

9. Akfix 840 Fire Block

• Material Type: Polyurethane Foam

Best for: Small fireblock repairs.

Why it ranks #9: A two-can fire-retardant polyurethane foam for gap filling, insulation, and sealing around windows and doors; its listing says it is paintable.

Akfix 840 comes as a two-can, 12 oz-per-can option for buyers who want fire-retardant expanding foam without a larger multi-can kit. The listing identifies it for gap filling, insulation, and sealing around windows and doors, and says the cured foam is paintable.

The polyurethane foam is described as fire rated and intended for fire resistance and insulation, giving it a focused role in sealing building openings. Expansion supports filling gaps, while the paintable finish offers a route to a neater appearance after curing. The two-can quantity is suited to contained work rather than broad wall or attic coverage. This listing does not provide a numerical fire-test result, R-value, or included gun, so buyers should base selection on the stated uses and package contents.

Skip it if you need quantified thermal performance for a broad insulation project; BEEST FullStop 120 Board ft 6-pack lists an R-value of 8.24 at 2 inches.

Akfix 840 fits buyers handling smaller window or door gaps who want fire-rated foam that can be painted after curing. Its two-can scale and unlisted numerical performance figures are important planning boundaries.

Listed on Amazon as: Akfix 840 Fire Block Spray Foam (2×12 Oz.)- Orange Color Fire Retardant Polyurethane Expanding Foam for Gap Filling, Insulation and Sealing on Window and Door, Fire Rated, Paintable | 12 Oz. 2 Pack

#10

10. Stanley F952 Foam

• Material Type: Polyurethane Foam
• Compatible Material: Wood, Concrete, Drywall, Metal, Plastic, Rubber
• Form: Spray

Best for: Indoor-outdoor gap sealing.

Why it ranks #10: This two-pack is described as fire-rated expanding polyurethane foam for sealing doors, windows, walls, pipes, and joints, but provides fewer performance details.

Stanley F952 is explicitly listed for indoor and outdoor straw use, giving buyers a straightforward option for sealing gaps at doors, windows, walls, pipes, and joints. The two 12 oz cans contain expanding polyurethane foam, with compatibility listed across wood, concrete, drywall, metal, plastic, and rubber.

The straw-use application suits targeted sealing at openings and joints rather than a gun-based kit workflow. Its listed material compatibility spans rigid surfaces such as concrete and drywall as well as rubber, supporting use across varied repair locations named in the title. The two-can quantity offers separate cans for multiple tasks, while the listing does not provide a fire-test standard, expansion figure, or thermal rating to guide performance comparisons or insulation calculations.

Skip it if you require a stated fire-test classification and thermal rating; BEEST FullStop lists ASTM E84 results and an R-value of 8.24 at 2 inches.

This Stanley two-can option suits buyers making targeted indoor or outdoor seals across its listed materials with straw application. It is a less informative fit when documented fire-test and thermal-performance figures are central to selection.

Listed on Amazon as: Stanley F952 Fire Block Spray Foam – (2x12oz) Fire Rated Expanding Polyurethane Foam Sealant for Gap Filling & Sealing on Doors, Windows, Walls, Pipes & Joints – Indoor/Outdoor Straw Use | 2 Pack