Fire Block Foam is an expanding polyurethane foam engineered to help slow the spread of fire, smoke, and air movement within concealed spaces such as wall cavities, top plates, utility penetrations, and framing joints. Its orange color provides visible identification during inspections, and its Class A fire rating ensures compliance with key building and fire safety standards. Whether you're sealing around electrical penetrations, plumbing lines, or attic openings, Fire Block Foam delivers durable insulation, airtight sealing, and added fire resistance.
Explore our full range of fire-rated foams designed for residential and commercial applications requiring compliant, high-performance fire blocking.
Why Use Fire Block Foam?
Fire Block Foam is formulated specifically to meet fire-blocking requirements; not to be confused with fire-stopping materials and provides several important benefits:
- Class A fire-rated formulation to help slow fire propagation
- Orange color for easy inspection and building code identification
- Strong adhesion to wood, concrete, metal, drywall, and masonry
- Fast expansion to seal gaps, joints, and penetrations
- Airtight, moisture-resistant, and mold-resistant curing
- Ideal for meeting fire-blocking requirements in IRC/IBC assemblies
- Available in both straw-grade and gun-grade for any project scale
Perfect for contractors, electricians, plumbers, HVAC installers, and DIY users working on code-compliant fire-blocking applications.
For a wider range of sealing and insulation solutions, explore our full collection of Foam Sealants.
Fire Block Foam vs Fire Stop Caulk
Fire Block Foam is used to slow the spread of fire by blocking air movement inside wall cavities, top plates, and framing gaps. It is IRC/IBC fire-blocking compliant and is easily recognized by its orange color, making it ideal for general construction and DIY air-sealing tasks.
Fire Stop Caulk, on the other hand, provides a fully rated fire-stop seal for through-penetrations that require an hourly fire rating, meeting ASTM E814 and UL 1479 standards. It is typically red, designed for pipes, ducts, and assemblies where code requires a true fire-stopping system.
Fire Block Foam is not a substitute for fire-stopping materials.
Best Uses for Fire Block Foam
- Sealing wall penetrations around pipes, conduits, and cables
- Filling gaps around electrical boxes and utility lines
- Blocking air movement in top plates and framing joints
- Fire-blocking in attics, crawl spaces, and basements
- Sealing penetrations in HVAC and plumbing chases
- Enhancing energy efficiency by reducing drafts
- Meeting inspection requirements for fire-blocking assemblies
How to Apply Fire Block Foam
- Clean and dry the surface; remove dust and debris.
- Lightly mist the area for improved adhesion.
- Shake the can vigorously and attach the straw or gun applicator.
- Hold the can upside down and apply foam slowly from bottom to top.
- Do not overfill; foam will expand significantly.
- For large voids, apply in layers and allow brief curing between passes.
- Allow 24 hours for full cure.
- Trim excess foam and protect from UV with paint or plaster.
Gun foam options offer superior control, higher yield, and professional precision.
Recommended Fire Block Foam Products
Below are our top-rated Class A Fire Block Foams trusted by contractors and DIY users.
H3. Stanley F952 Orange Fire Block Foam Sealant – Straw Applicator, 12 oz / 24 oz
Class A fire-rated, UL classified, and ASTM E84201 compliant. Provides strong adhesion, high expansion, and excellent moisture and mold resistance.
Explore Stanley F952 Fire Block Foam for full specs and purchase options.
Akfix 840P Fire Rated Polyurethane Gun Foam – 25.3 oz
Professional gun-grade fire-rated foam with high yield, strong adhesion, and Class A fire classification.
View Akfix 840P Fire Rated Gun Foam to compare performance and coverage.
Sprayman Orange Fire Block Foam – Straw Applicator, 12 oz
Easy-to-use, Class A fire-rated straw foam ideal for electrical boxes, vents, and narrow spaces. UL-listed and ASTM-compliant.
See Sprayman Fire Block Straw Foam for detailed specs and pricing.
Sprayman Pro Fire Block Foam – Gun Foam, 20 oz
High-performance, professional-grade foam for large cavities and utility penetrations. Excellent fire resistance and high yield.
Browse Sprayman Pro Fire Block Foam for pro-level applications.
Akfix 840 Fire Block Insulating Foam – Straw Applicator, 12 oz
High-expansion, Class A-rated fire-blocking foam with strong adhesion and mold/water resistance, ideal for framing applications.
Shop Akfix 840 Fire Block Foam to compare sizes and features.
Kraken Bond Extreme Fire Block Foam – Straw Applicator, 12 oz / 24 oz
Eco-friendly, high-yield, Class A foam providing excellent fire resistance, adhesion, and insulation in residential or commercial structures.
Explore Kraken Bond Extreme Fire Block Foam for reliable fire-blocking protection.
Frequently Asked Questions (FAQ)
What is Fire Block Foam?
Fire Block Foam is an orange, Class A-rated polyurethane foam designed to slow fire and smoke movement by blocking air pathways in wall cavities and framing assemblies.
Is Fire Block Foam code-compliant?
Yes. Fire Block Foam meets IRC/IBC fire-blocking requirements and is UL classified and ASTM E84 tested. It is not a fire-stopping product.
Can I use Fire Block Foam around electrical wiring?
Yes. Fire Block Foam is suitable for sealing around wires, conduits, and electrical boxes, provided surfaces are clean and dry.
Can you use Fire Block Foam on PVC pipe?
Yes, Fire Block Foam is generally compatible with PVC, but always follow local code requirements and manufacturer guidelines.
How long does Fire Block Foam take to cure?
Most products tack in 3–7 minutes and fully cure within 24 hours.
Fire block vs fire stop: what’s the difference?
Fire block slows fire spread by blocking air movement. Fire stop maintains a fire-resistance rating in through-penetrations.
Is Fire Block Foam safe indoors?
Yes. Once fully cured, it is low-VOC and safe for indoor use.
Does Fire Block Foam expand a lot?
Fire block formulations typically offer medium–high expansion to fill gaps and ensure airtight sealing.
What’s the best Fire Block Foam for residential projects?
Class A, UL-classified foams such as Stanley F952, Sprayman Pro, and Kraken Extreme are top-performing options.
Can Fire Block Foam be painted?
Yes. After curing, it can be trimmed, sanded, and painted for a finished appearance.