Design and Construction Practices for Firestopping in Accordance with FM Standards for Structurally Critical Facilities

FM-compliant Firestop Design and Construction Practices Forming the First Line of Defense for Critical Facilities

In modern critical infrastructure such as data centers, telecom equipment rooms, high-voltage direct current converter stations (HVDC) and lithium battery energy storage systems (BESS), firestop systems are not only part of a building's passive fire protection but also the primary barrier to prevent the spread of fire, smoke and toxic gases. As the international risk-control standards setter, FM’s published Data Sheets 5-14, 5-25, 5-31, 5-32, 5-33 provide specific and rigorous design and construction requirements for sealing openings in fire-resistance rated assemblies.

• Key FM requirements for firestopping

1. FM-approved systems must be used Whether cables, cable trays, busbars, ducts or pipes, any penetration through fire-rated walls or floors must be sealed using FM Approved or Listed firestop systems (refer to DS 5-14, 5-31, 5-32, 5-33).

• Fire-resistance rating must match the penetrated assembly

FM requires that the fire-resistance duration of the firestop system must not be less than the fire rating of the wall or floor being penetrated, for example:

• Telecom/power equipment rooms and lithium battery energy storage areas: 2-hour fire rating (DS5-14, 5-33)

• UPS rooms, data processing equipment rooms: 1-hour fire rating (DS5-32)

• Valve halls of HVDC converter stations and adjacent areas: 1-hour firestopping (DS5-25)

• Leakage rating (L-Rating) requirements

For sensitive equipment areas (such as data centers and telecom rooms), FM also requires that the firestop system provide low air leakage performance in the pre-fire stage, with a leakage rate of ≤7 ft³/min/ft² (2.1 m³/min/m²) to control initial smoke ingress (DS5-145-32).

• FM4991: certification assurance for professional installation

High-standard products must be correctly installed by professional installation teams to achieve complete fire performance. FM DS5-31 explicitly recommends selecting companies that hold FM4991 firestop contractor certification to perform firestopping work.

Why choose an FM4991-certified contractor?

• Robust quality control system: including material management, construction procedures, inspection processes and complete records
• Certified construction personnel: regular training, testing and requalification to ensure skill levels
• Strong traceability of works: every penetration has construction records and tag numbers
• Higher compliance and recognition: greater credibility during insurance, review and owner acceptance

For example, Shanghai Tengxi Construction Engineering Co., Ltd., as an FM4991-certified professional contractor, possesses systematic quality management capabilities and can provide full-process, traceable, international-standard firestopping solutions for high-grade facilities.

• Best practice summary

The following combination ensures firestopping meets FM requirements and achieves optimal protection:

• FM Approved firestop materials (matching fire-resistance and leakage ratings)
• FM4991-certified contractor professional installation (ensuring construction methods and quality control)
• Standardized labeling and acceptance procedures (facilitating management, review and maintenance)

This product + installation + management trinity is the most reliable FM-compliant firestopping practice for current data centers, telecom, power, energy and other facilities.