Anodized Aluminum Building Facade

Question:

Part of our work is to assess the condition of buildings for our clients. We have recently heard that anodized aluminum panels on the outside of a building would last only about 50 years before they have to be re-anodized to the tune of about $1M. My research, so far, has yielded no information either pro or con. I’m a structural engineer and I’m not all that knowledgeable about anodized metals, but I’m guessing that an anodized panel would last as long as the building, although it might fade, or become stained. Is there an estimated useful life (EUL) for architectural anodized aluminum? J.M.

Answer:

I’ll give you the short answer and if you have further questions, please don’t hesitate to ask.

Generally speaking, a Class I architectural anodized finish, as designated in AAMA 611-92, is considered a 100 year finish if it has been processed meticulously to the process standards.  The conditions under which the parts are anodized and sealed will ultimately tell the tale as to whether the anodic coating will last that long.

 It’s not quite as simple as that, however, because the local environment can affect the useful life of the finish, as well (just as it affects paint, masonry, etc.).  Stained, or even mildly oxidized (corroded), architectural anodized aluminum can most often be cleaned and restored without the necessity of removing and re-anodizing, which is impractical.  There are professional companies out there who do this and the results are most often quite remarkable.