Metal Roof Care: How to Prevent Galvanic Corrosion

The zinc coating on galvanized metal helps protect it from corrosion. However, installation errors can damage the coating. The commercial roofing contractors at McGuire Roofing & Construction share some tips on how to prevent this from happening below.

Galvanic Corrosion on Metal Roof

Dissimilar Metals 

One of the most common installation errors is using roof components made of dissimilar metals. A pair of metals are dissimilar to each other if they’re far from each other on the “Electrochemical Series” chart. If the two came into contact with water and each other, the metal that’s higher up in the chart (the less noble metal) will start to corrode.

Avoid Copper and Lead

What are the metals that can be safely used together? Copper and stainless steel are a safe combination. Avoid pairing copper with lead.

Keep in mind that it only takes a small amount of copper or lead to start the corrosion process. Traces of these metals can come from unexpected sources. For example, treated wood usually contains trace amounts of copper. Condensation dripping from your AC can also contain copper; the coils, after all, are made using the same metal. It is also be a good idea to avoid marking aluminum panels with a pencil, which contains graphite.

Since it can be hard to know whether a certain component contains copper or lead, you should consult one of your local roofing contractors. A contractor can design your roof in a way that will prevent dissimilar metals from coming into contact with your metal.

Just make sure to hire a certified contractor. That way, you can make sure your roof is properly installed and even get better value for your money. Manufacturers like GAF® offer exclusive warranties to roofing systems installed by certified contractors.

Looking for certified contractors in your area? McGuire Roofing & Construction, a GAF® Master Elite™ contractor, offers professional residential roof construction services. To get a free estimate, call us at (865) 338-7663. Or leave us a message on this form. We serve homeowners in Oak Ridge and Knoxville, TN.



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