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What Causes Galvanic Corrosion on Metal Roofs?

What Causes Galvanic Corrosion on Metal Roofs?

Metal is arguably one of the most popular materials for roofing — all thanks to its inherent strength, durability and incredibly long lifespan. However, there are circumstances under which corrosion can become a real issue. Fortunately, having basic knowledge and understanding of the common causes of galvanic corrosion can be really helpful and help mitigate costly problems in the future.

What Causes Galvanic Corrosion on Metal Roofs?

Lead and copper are chemical elements that can deteriorate and significantly reduce the service life of metal roofing due to unwanted corrosion. It is critical to make sure that these soft and malleable metals do not come into contact with the roof. Take a closer look at the common issues that can arise.

Lead with Metal Roofing

It is not advisable to use lead roofing products, particularly lead roof jacks for pipe penetrations, due to the high probability of corrosion. Graphite is also extremely corrosive to aluminum and aluminum alloys. This means it is smart to use a graphite pencil to mark a metal panel. This is because the confounding element will eat through the coating and cause it to rust out over time.

Copper with Metal Roofing

Copper is another metal that reacts poorly with galvanized metal products. An experienced roofing contractor will not use treated lumber during installation since it has copper in it. But what if treated lumber or a lighting system with a cable is required? A smart alternative to avoid chemical reactions that will cause corrosion is to ensure that the cable has aluminum instead of copper.

Copper can also be an issue if you have an AC on your metal roof. It is possible that the cooling unit has copper in the coils, and when condensation drips out onto the roof with traces of copper in the water, those droplets will signal the corrosion. Make sure to install PVC piping all the way up the roof to prevent copper from making contact.

Mascon, Inc. is a premier source of top-rated residential roofing solutions in and around Austin, TX. Our dedicated team aims to provide the safety and comfort that you need in your home through industry-leading products and maintenance services. Call us today at (512) 376-5096 or fill out our contact form to set up an appointment.