Cable trays passing through ordinary shear walls

Cable trays can pass through ordinary shear walls if proper firestopping, structural support, and penetration sealing are applied to maintain wall integrity and safety.

Structural Considerations

When routing cable trays through shear walls, it is crucial to avoid compromising the wall's structural performance. Ordinary shear walls are designed to resist lateral loads, so any openings must be carefully planned. Openings should be minimized in size and positioned to avoid critical stress zones. Large penetrations may require reinforcement or backing plates to maintain wall strength and prevent cracking or deformation under load .

Firestopping and Penetration Sealing

Cable trays passing through walls must be sealed with fire-rated materials to prevent the spread of fire, smoke, and toxic gases. Common firestopping methods include:

• Firestop packs or mineral wool with fire-retardant coatings
• Firestop mastic or intumescent caulks for sealing gaps around trays
• Fire-resistant backing plates for large openings to support sealing materials The gap between the cable tray and wall opening should be minimal, typically not exceeding 1 cm², and the packing thickness should meet the fire rating requirements. Cover plates should be square, evenly painted, and securely fixed to complete the seal .

Installation Guidelines

• Use perforated or wire mesh trays to improve airflow and prevent heat accumulation .
• Maintain adequate clearance between cables to avoid overheating.
• Ensure tray alignment and grounding continuity to prevent mechanical or electrical hazards .
• Inspect for corrosion or deformation before and after installation, especially in outdoor or high-moisture environments .

Compliance with Standards

Cable tray penetrations should comply with relevant standards:

• UL Listed systems for fire-rated walls, specifying F-Rating and T-Rating for concrete or gypsum walls .
• European Standards EN 1366-3 and EN 13501-2 for penetration seals, classifying cable types and configurations .
• BS EN 61537 for cable tray manufacturing and installation practices .

Summary

Passing cable trays through ordinary shear walls is feasible if structural integrity is preserved, firestopping is properly applied, and installation follows recognized standards. Planning the penetration location, using appropriate fire-rated materials, and performing regular inspections are essential to ensure both safety and long-term performance.