Cable Containment & Pathway Coordination with MEP Services in Ireland

Cable containment coordination is the single most expensive site-discovered clash category on Irish ICT and ELV projects. When ICT cable tray conflicts with HVAC ductwork above a suspended ceiling — and this discovery is made by the ICT installer on site rather than by the design team in a federated BIM model — the cost is typically ten to twenty times what it would have been to resolve the conflict at design stage. The ICT installer must alter their containment route, which may require revisiting the cable schedule and length calculations; the MEP contractor and HVAC contractor must agree on who relocates what; the main contractor manages a variation claim; and the project programme slips. This guide provides the complete technical framework for cable containment design and BIM-coordinated pathway planning on Irish ICT and ELV projects.

Why Containment Coordination Fails on Irish Projects

ICT containment coordination failures on Irish construction projects follow a consistent pattern. The ICT design is produced after MEP coordination has already begun — often because ICT is the last discipline to be appointed on the design team, or because the ICT sub-consultant is not included in the BIM coordination meetings. The ICT containment drawing is produced in isolation, without reference to the coordinated MEP model. By the time the ICT drawing is issued for construction, the ceiling space is already conceptually claimed by HVAC ducts, sprinkler mains and pipework — and the ICT containment routes are not feasible as drawn.

The three root causes of ICT containment coordination failure on Irish projects:

• Late ICT design appointment: ICT sub-consultants are often appointed at Stage 4 (technical design) rather than Stage 2–3, meaning containment routes are not reserved in the MEP coordination from the outset. Main duct routes, primary pipework and structural penetrations have already been agreed before ICT containment exists as a design entity
• ICT not in the BIM model: on some Irish projects, ICT containment is still drawn in AutoCAD 2D rather than modelled in Revit — meaning it cannot participate in the federated Navisworks clash detection workflow. 2D drawings are compared visually, which is slower and less reliable than automated clash detection
• Undersized containment: ICT containment is designed without BIM coordination, running in spaces that are conceptually available on 2D drawings but physically occupied by MEP services that are not shown at the same ceiling level. On site, the ICT contractor finds there is no space for the designed containment run

Containment Types and Applications

BS EN 61537: Cable Tray and Ladder Standard

BS EN 61537 is the European standard for cable tray and cable ladder systems (adopted in Ireland via NSAI). It covers:

• Load ratings: L1 (12.5kg/m), L2 (25kg/m), L3 (50kg/m), L4 (75kg/m), L5 (100kg/m) — expressed as uniformly distributed load capacity per metre of span. For ICT cable tray on Irish commercial projects, L2 (25kg/m) is typically sufficient for horizontal runs up to 1.5m span. For vertical risers carrying large cable bundles, L3 or L4 may be required
• Support spacing: determined by load rating and cable weight — typically 1.5m for horizontal ICT tray in office environments. Riser clamps at 1.0m for vertical runs. BIM families for cable tray must include support brackets modelled at the correct spacing for accurate structural loading information
• Material specification: galvanised steel is the standard for internal Irish commercial environments; stainless steel for wet areas, food processing or coastal locations; aluminium for non-magnetic environments (MRI rooms, some laboratory environments). Powder-coated finishes available for exposed architecturally visible tray in modern Irish office interiors

Fill Ratio Calculation: Worked Example

For a typical ICT backbone route on a Dublin commercial office floor serving 96 outlets in four zones, carrying 24 Cat6A cables to the central TR:

1. Cable cross-sectional area: Cat6A UTP cable, 8.0mm OD → cross-sectional area = π × (4.0)² = 50.3mm² per cable
2. Total cable area: 24 cables × 50.3mm² = 1,207mm²
3. Required containment area at 50% fill: 1,207mm² ÷ 0.50 = 2,414mm²
4. Select containment: 100mm wide × 50mm deep cable basket = 100 × 50 = 5,000mm² internal area → fill ratio = 1,207 ÷ 5,000 = 24.1% at current load. This comfortably accommodates 100% future growth (48 cables = 2,414mm² = 48.3% fill — still within 50% design limit)
5. Alternative for trunking: if surface trunking is used instead (cellular office corridor), 100mm × 100mm trunking = 10,000mm² — allows up to 99 Cat6A cables at 50% fill, which is excessive. Size down to 75mm × 50mm = 3,750mm² (50% = 1,875mm² → 37 cables) if appropriate for the zone cable count

This calculation must be performed for every distinct containment segment — the backbone tray nearest the TR will carry the most cables; perimeter runs serving individual zones will carry fewer. Over-sizing throughout (using the maximum cable count on every segment) wastes material and ceiling space on Irish projects where space is at a premium. Segment-by-segment sizing from the containment drawing is the correct approach.

Separation Distances from Other Services

These separation distances are specified in EN 50174-2 (the European ICT installation standard) and IEC 60364 (electrical installation standard). On Irish projects, the electrical engineer's specification will also reference these separations. The ICT designer and electrical engineer must coordinate containment drawings to ensure separations are maintained in the confined ceiling space of a typical Irish commercial building.

BIM Coordination Workflow for Irish ICT Containment

The BIM coordination workflow for ICT containment on ISO 19650 Irish NDP projects follows a defined sequence:

1. ICT containment modelling in Revit: the ICT sub-consultant (or ASDV as ICT designer) models cable tray, basket tray and trunking routes using Revit MEP cable tray families. Standard Autodesk cable tray families are suitable; proprietary manufacturer families (OBO Bettermann, Cablofil, Legrand) provide more accurate geometry. Containment is modelled at the correct size (from the fill ratio calculation), at the correct elevation (coordinated with the architect's reflected ceiling plan), and with the correct offset from structural elements (from the structural model)
2. Model federation: the ICT Revit model is federated in Navisworks with: the architectural model, the structural model, the HVAC model, the plumbing/drainage model, and the electrical LV containment model. The federated model shows all disciplines simultaneously in a shared coordinate system
3. Automated clash detection: Navisworks Clash Detective runs automated clash tests between ICT containment and each other discipline. Results are exported as a clash report with clash type (hard/soft/clearance), discipline pair and location reference
4. Clash resolution: the ICT designer reviews each clash and proposes resolution — typically rerouting containment to avoid the conflicting element, adjusting elevation, or negotiating with the MEP engineer to relocate the conflicting duct or pipe. Resolved clashes are remodelled and verified in the next Navisworks check
5. CDE publication: the clash-free coordinated ICT containment model is published to the Common Data Environment (Autodesk Construction Cloud, Microsoft SharePoint CDE or Viewpoint for Projects) as a Coordination Review issue per ISO 19650 information management protocols. This creates a documented audit trail of coordination completion

Common Clash Types on Irish Projects

From ASDV's experience coordinating ICT containment on Irish commercial and healthcare projects, the most common clash categories are:

• Hard clash: ICT backbone tray vs. HVAC supply duct (most common): the main HVAC supply duct to an open-plan floor typically runs along the primary corridor at ceiling level — exactly where ICT backbone containment wants to run. On a 1,200mm × 600mm HVAC duct with 300mm clearance above the suspended ceiling, there may be only 100–200mm of remaining vertical space for ICT containment — insufficient for a 50mm deep cable basket plus support brackets. Resolution: ICT tray runs parallel to and below the HVAC duct (reducing from a standard 2,400mm to 2,200mm suspended ceiling height in the corridor), or rerouted to the opposite wall
• Clearance clash: ICT tray vs. structural beam: primary structural beams in Irish steel-frame commercial buildings (common in Dublin business parks) project 300–450mm below the underside of the slab. ICT riser containment crossing these beams must pass through or below. Penetrating the beam web requires a structural engineer's approval for openings; passing below reduces available ceiling clearance. Resolution: structural openings pre-planned during superstructure design, with ICT designer providing penetration size requirements before steelwork is fabricated
• Workflow clash: ICT tray vs. fire damper access zone: fire dampers in HVAC ducts must have clear access for inspection and resetting. Irish building regulations and HVAC good practice require a 600mm clear zone around each fire damper. ICT containment that crosses within this zone without physical clash may still obstruct the damper access — a workflow clash that prevents proper maintenance