Below is a practical, code-aware summary of the best materials used for passive fire protection in commercial buildings, where they are used, their strengths/limitations, and selection/inspection tips.

Key goals of passive fire protection (PFP)

• Contain fire and smoke (compartmentation) to protect occupants, maintain egress, and limit structural damage long enough for evacuation and fire service intervention.
• Maintain fire-resistance ratings (e.g., 1, 2, 3 hours) required by code for walls, floors, columns, beams, shafts, doors, and penetrations.

Common materials and systems

1. Concrete and masonry

• Where used: structural elements, fire walls, shaft enclosures, floor slabs.
• Strengths: inherently fire-resistant, durable, low maintenance, high thermal mass.
• Limitations: heavy, less flexible for penetrations/retrofit.

2. Fire-rated gypsum board (Type X / shaftliner)

• Where used: fire-resistance-rated walls and ceilings, shaft liners, corridor walls.
• Strengths: economical, easy to install, available in many ratings when installed in tested assemblies.
• Limitations: must be installed per tested assembly; damaged/wet gypsum loses performance.

3. Mineral wool (rock/stone wool) insulation

• Where used: cavity insulation, around penetrations, between studs, around ducts, to back up intumescent coatings.
• Strengths: non-combustible, high temp resistance, acoustical benefits, easy to cut and pack for firestopping.
• Limitations: must be used with compatible sealants or mechanical supports in penetrations.

4. Cementitious and spray-applied fire-resistive materials (SFRM) / board-applied cementitious products

• Where used: fireproofing structural steel (columns, beams), underside of slabs.
• Strengths: effective at insulating steel to maintain structural integrity; available for different hour ratings.
• Limitations: thickness and adhesion control important; susceptible to damage/abrasion; may require protection/inspection.

5. Intumescent coatings and wraps (paint-on or factory-applied)

• Where used: structural steel, cable trays, pipes; also for firestopping collars and wraps around penetrations.
• Strengths: thin-profile solutions that expand under heat to insulate substrates; good for architectural exposures.
• Limitations: performance is product- and thickness-dependent; coatings must be evaluated for exposure, durability, and service environment.

6. Firestopping sealants and mortars (rated systems)

• Where used: sealing penetrations (pipes, conduits, cable bundles) and head-of-wall joints, control joints.
• Types: water-based/acrylic intumescent sealants, silicone sealants, elastomeric mastics, cementitious mortars, firestop pillows/blocks.
• Strengths: essential to restore continuity of rated assemblies; many tested UL/ASTM systems for different conditions.
• Limitations: must be installed per tested system; inappropriate product choice or poor workmanship defeats a rated assembly.

7. Fire doors and frames (steel, wood with cores, glazing)

• Where used: means-of-egress doors, stair enclosures, corridor doors.
• Strengths: provide rated closures for compartmentation and egress; available in 20–120+ minute ratings.
• Limitations: hardware, gaps, and improper strips can reduce rating—correct clearances and automatic closers required.

8. Fire-rated glazing and framing systems

• Where used: vision panels, storefronts in rated walls, atrium enclosures.
• Strengths: allows light/visibility while maintaining rating when properly tested and installed.
• Limitations: glazing and framing must be part of complete tested assembly; size/edge conditions matter.

9. Calcium silicate boards, vermiculite boards, and ceramic fiber boards

• Where used: fire barriers, duct wrap, fire doors, protection of penetrations and structural members.
• Strengths: high temperature resistance, stable, used where higher temps or thin profiles required.
• Limitations: some fiber boards are regulated for handling; select based on manufacturer guidance.

10. Collars, wraps, and sleeves for pipes and cable trays

• Where used: at through-penetrations through rated walls/floors.
• Strengths: engineered solutions for common penetration types; often intumescent-based to close openings when heated.
• Limitations: must match pipe material, size, and penetrant type; rely on tested system.

11. Fire-resistant glazing and fire-rated partitions for shafts and atria (specialized systems)

• Where used: stair shafts, elevator shafts, atria enclosures.
• Strengths: preserve compartmentation for high-clearance spaces.
• Limitations: expensive and must be specifically tested.

Selection criteria and best practices

• Use tested and listed systems: choose materials that are part of complete tested assemblies (UL, FM, or other recognized test standards such as ASTM E119 for assemblies and ASTM E814/UL 1479 for penetrations).
• Choose the right rating: specify the required fire-resistance rating (hours) per code (IBC/NFPA or local code) for each element and select materials/assemblies that achieve that rating.
• Compatibility: ensure sealants, insulation, and substrates are compatible (chemical, thermal, and mechanical).
• Durability & exposure: for exterior or humid/industrial environments, select materials resistant to moisture, vibration, or mechanical damage.
• Maintainability and inspectability: prefer systems that allow inspection (access panels where required) and repair; maintain records of installed firestop systems and their tested designs.
• Consider smoke control: seal continuity against smoke with suitable smoke-rated seals (some codes require smoke and fire protection).
• Aesthetics and building use: intumescent coatings and thin boards can be used where appearance matters.
• Structural protection: for steel members that must maintain strength, use SFRM or intumescent coatings sized to achieve the required fire-resistance period.

Installation, inspection and maintenance

• Follow manufacturer instructions and tested system drawings exactly.
• Only trained/certified installers should perform firestopping and fire door installations.
• Keep a firestop register with the tested system IDs and locations; many jurisdictions require this at turnover.
• Conduct periodic inspections (fire doors annually or per code, firestops per local authority or project specification) and repair damage promptly.
• Recordkeeping: maintain as-built documentation and product data sheets for future audits and repairs.

Codes and standards (to reference)

• International Building Code (IBC) and local amendments
• NFPA 101 (Life Safety Code)
• NFPA 80 (Fire Doors and Other Opening Protectives)
• NFPA 221 (Outside Combustible Walls)
• ASTM E119 (Standard Test Methods for Fire Tests of Building Construction and Materials)
• ASTM E814 / UL 1479 (Penetration firestop tests)
• UL listings and manufacturer’s tested system documentation

When to consult specialists

• Complex penetrations (large cable trays, mixed penetrants), unusual architectural conditions, or high-rise/complex projects — involve a fire protection engineer, certified firestop contractor, and the Authority Having Jurisdiction (AHJ).

Bottom line No single “best” material fits every application. Use non-combustible substrates (concrete, masonry), tested fire-resistive assemblies (gypsum, cementitious fireproofing, mineral wool), and listed firestopping products (intumescent sealants, collars, mortars) matched to the assembly and code-required rating. Prioritize tested systems, proper installation, and routine inspection/maintenance to keep passive fire protection effective.

If you want, I can:

• Outline recommended materials by specific building element (e.g., columns, floors, tenant partitions, penetrations), or
• Provide a short checklist for evaluating firestop product submittals and fire door installations.