Over time, your metal cladding roof deteriorates due to elemental damage such as heavy rain or frost and even the highest quality cladding is not 100% safe from the brunt force of nature. Damage to the roof may take a little bit longer but, ultimately, it is inevitability. One type of damage to look out for on metal cladding is sheet edge or cut edge corrosion, which can lead to more problems, and should be treated immediately.
Cut edge corrosion is the first sign of metal cladding deterioration and it is characterised by the peeling back of the factory coating and visible corrosion of the cut edge. This kind of corrosion usually results from the accumulation of pollution, as well as moisture on the edges of the cladding sheets, which causes delamination. Since the metal substrate is no longer protected from the elements, it quickly corrodes and rusts.
If the problem is left unattended, the corrosion will spread beyond the cut edge and further into the metal sheet. It will then affect the lap joints as well as the gutter overhang and soon enough, leaks will start to form, letting unwanted water into the structure. The quality of the cladding will be compromised and extensive repair and maintenance will be required to get it back to its’ original state.
Thankfully, cut edge corrosion is easy to treat as long as the problem is addressed as soon as it is detected. This will ensure the damage is only limited to the edge of the metal sheet. Treatment involves the application of Seamsil, a silicone remedial system created for edge sealing and protection. However, before Seamsil can be applied, the area affected by the delamination and rusting will need to be thoroughly cleaned and prepared which includes the removal of the peeling and/or flaking factory coating.
The application of Seamsil as a treatment for cut edge corrosion is a three step process. First, Seamsil sealant will be applied to the edges of the metal sheeting; the sealant is applied using a gun to seal the overlapping joints which were affected by the corrosion. Secondly, Seamil will be applied a second time, with a brush, over the top of the previously sealed joints. For the third and final step, a roller brush will be used to apply a topcoat over the treated edges of the metal roofing in a neat strip or band and should match the existing colour of the roofing.
There are many contractors offering this type of treatment for cut edge corrosion so building owners or caretakers need not deal with the problem themselves. When choosing your contractor, pick someone who has been working in the industry for years who has extensive experience in treating sheet edge corrosion, and can provide a list of client references should you want them.