FAQ: Frequently Asked Questions – Cable Management

Metsec does not supply a deep‑galvanised finish. Instead, we offer a selection of corrosion‑resistant material options that ensure our containment and support systems perform reliably in a wide range of environments. These include ZM coatings, hot‑dip galvanised (HDG) finishes, and stainless‑steel solutions, each providing strong durability across the recognised corrosion categories.

Our HDG cable ladder and cable tray systems are galvanised to BS EN ISO 1461 and classified under BS EN 61537, with minimum mean zinc coating thicknesses of 55 µm for Class 6 cable ladder and 45 µm for Class 5 cable tray. For more demanding environments, stainless‑steel options are available to provide enhanced corrosion resistance.

Although deep galvanising is not part of our product range, the materials we do offer provide long‑term, robust performance suitable for a wide variety of installation conditions.

Metsec can manufacture the following maximum widths:

• Cable Tray – 900 mm × 50 mm
• Cable Ladder – 1200 mm (available in any depth)
• Cable Trunking – 450 mm × 150 mm

These dimensions are not part of our standard product range and are supplied as non‑standard items, which is reflected in both pricing and lead times. For more information, please consult the Metsec Cable management Technical Department.

Metsec’s cable trunking systems provide enhanced ingress protection primarily through IP4X-rated solutions, which prevent the entry of solid objects larger than 1 mm and reduce the risk of contact with live parts, supporting compliance with standards such as BS 7671 and BS EN IEC 61084.

This level of protection is achieved using standard trunking components with IP4X clip kits, offering a practical and robust alternative to IP30 or IPXXD. However, these systems are not designed to provide higher levels of ingress protection against water (e.g., IP65/IP66), as IP4X focuses solely on solid object protection and does not include a liquid ingress rating.

Metsec cable management systems are available with a range of finishes, including powder coating as an optional specification. Standard products are supplied in pre‑galvanised steel, with powder coating applied to order to meet aesthetic or environmental requirements. The powder coating is typically polyester based as standard and is offered in a wide range of RAL colours and levels of gloss providing a durable, corrosion‑resistant and visually adaptable finish for a variety of applications.

Zinc whiskers are extremely fine, hair-like metallic filaments that can grow on zinc-coated surfaces over time. In cable management systems, they are most commonly associated with pre-galvanised steel manufactured to BS EN 10346, where their formation is possible. By contrast, zinc whiskers are extremely rare on hot dip galvanised steel manufactured to BS EN ISO 1461.

While the phenomenon is recognised in industry guidance (including the BEAMA best practice guide), it is important to note that there have been no reported instances of equipment failure caused by zinc whiskers on cable management systems.

Zinc flakes, on the other hand, are very small, thin films of zinc that can form on the surface of hot dip galvanised components (BS EN ISO 1461). These flakes typically develop during the galvanising process after manufacture and are often found in areas such as perforations. During normal finishing, handling, storage, and transportation, from the product.most zinc flakes naturally detach

Pre-galvanised products (BS EN 10346), such as those supplied by voestalpine Metsec plc, do not exhibit zinc flakes, as the coating is applied before fabrication.

At Metsec, we offer a range of material options that allow our containment and support systems to perform effectively in environments with elevated corrosion levels. ZM coatings, hot dip galvanised (HDG) finishes, and stainless steel solutions provide contractors with robust choices across the full spectrum of recognised corrosion categories.

BS EN ISO 12944-2 classifies environments according to their corrosivity, with C3 to C5 representing increasingly aggressive conditions:

• C3 (Medium): Urban and light industrial environments with moderate humidity and some pollution.
• C4 (High): Industrial or coastal areas with moderate salinity and higher corrosion rates.
• C5 (Very High): Highly aggressive environments such as heavy industrial zones or marine/coastal locations with high salinity and sustained moisture.
• As corrosion severity increases, more robust material protection is required. Suitable solutions include:
• Hot Dip Galvanised (HDG) steel – a durable and cost-effective option for many C3–C4 applications and some C5 environments when sufficient coating thickness is specified.
• Stainless steel – provides superior corrosion resistance, particularly suited to C4 and C5 environments where long-term performance is critical.
• Zinc Magnesium (ZM) coated steel – offers enhanced corrosion resistance and improved cut-edge protection compared to conventional galvanised coatings, making it suitable across C3 to C5 categories.

Material selection should always consider the specific environment, required service life, and maintenance strategy.

A hot dip galvanised coating provides a high level of corrosion protection due to the slow rate at which the zinc coating corrodes with the atmosphere. Part of the protection provided is by a zinc carbonate patina, which forms on the surface over a period of time due to the reaction to carbon dioxide from the atmosphere; this forms a thin layer of zinc oxide immediately after removed from the zinc bath.

When galvanized steel becomes damp and is unable to fully dry out, access to atmospheric carbon dioxide may be limited and as a result, the conversion to zinc carbonate does not take place. A layer of white powdery zinc corrosion that is comprised of zinc hydroxide and zinc oxide is formed and will continue to form for as long as the galvanized surface remains damp. This is known as wet storage stain or more commonly known as white rust.

The formation of wet storage stain can happen in areas of regular condensation, pooling of water or if the products have been shrink-wrapped which will result in poor ventilation which prevents drying.

Wet storage stain will typically have little if any significant effect upon the protection provided by the galvanized coating and under BS EN ISO 1461 is not grounds for rejection unless its formation has significantly reduced the coatings thickness in the short term.

Removal is not essential however if aesthetics is important then removal can be achieved with a stiff brush or wire wool. Deposits that are more tenacious can be removed with the use of chemical cleaning with a diluted acidic or ammonia solution and with mild abrasion. It should be noted that when wet storage stain is removed the bright shiny galvanised appearance might not be restored, as often a dark stain will be present.

The basic principles concerning avoidance of wet storage stain relate to maintaining a dry surface, or where this is not possible, trying to ensure that drying takes place to minimise the period of dampness. Avoidance of covering work with plastic sheet or shrink-wrapping should be considered as this can lead to moisture trapping and sweating.

• Zinc whiskers: Although theoretically capable of becoming airborne, there are no documented cases of failures in electrical equipment linked to cable management systems.
• Zinc flakes: Due to their larger size and greater mass, flakes are far less likely to become airborne or migrate into sensitive equipment. Similarly, no equipment failures have been reported as a result of zinc flakes.
• Summary
• Zinc whiskers may occur on pre-galvanised steel but are rare on hot dip galvanised products.
• Zinc flakes may occur on hot dip galvanised steel but not on pre-galvanised materials.
• In both cases, there is no evidence of these phenomena causing failures in cable management installations or associated electrical equipment.
• For further guidance, refer to the BEAMA best practice guide for cable ladder and tray systems, developed in collaboration with leading manufacturers.