Is cut Edge Corrosion Damaging Your Roofing System?

A number of commercial buildings, including warehouses, retailers and hospitals have corrugated steel or aluminium sheet cladding as a protective layer on their roofs. However, it is estimated that 60% of this cladding actually has cut edge corrosion.

Despite such a high number of buildings having cut edge corrosion, many owners are not even aware that their commercial properties are affected. However, if cut edge corrosion is left untreated, it can have devastating effects on the building.

What causes cut edge corrosion?

Cut edge corrosion usually starts as edge peel at the cut edges of a metal profiled roof sheet . The process starts through normal weathering of sheet overlaps and eaves, which then accelerates through capillary water held in the lap. The cut edges are vulnerable to weathering, oxidation and pollutants because they are left exposed and do not have a protective plastic coating that the rest of the metal or aluminum cladding has.

Metal also changes shape in extreme temperatures. When it’s hot the metal can expand and conversely when the temperature of the metal cools, it contracts. This can cause the protective coating to delaminate from the cladding – ultimately leaving it exposed to the elements.

Catching it early

Cut edge corrosion is a progressive problem and if neglected it can progress to destroying the weather-sealed lap joint and gutter overhang. It eats further into the metal and the problem becomes more than cosmetic. Serious cases can cause leaks in your commercial building, as well as compromising the building’s integrity.

Early detection and treatment of the edge peel will prevent a costly roof sheet replacement which heavily reduces the roofing costs and disruption at site. If cut edge corrosion is identified in the early stages the roof laps can be treated with a low modulus silicone system which will prolong the lifespan of the roof sheeting for in excess of 15 years.

However, if cut edge treatments are not done early, you may be looking at a full commercial roof repair which in turn, means an increase in cost and disruption.

Cut edge corrosion treatments

It is important to thoroughly clean any grime from the cladding before any repair is carried out. Loose paint, corroded areas and rust must also be removed before you can apply a weather and waterproof sealant. If the cladding is severely corroded then you may have to replace a number of the sheets. A metal cladding coating must then be reapplied for protection.

Here at NWIR, we can assess and evaluate your commercial cladding if you think you have cut edge corrosion. We carry out a thorough assessment before discussing treatment. If the problem is severe we can even carry out commercial roof repair. Contact us if you think your commercial building may have cut edge corrosion.