Metal roofing has a number of unique advantages over more traditional roofing materials, from it's immense durability and longevity to the ease with which metal roofing slats can be fitted and replaced. Unfortunately, most metal roofing types do have to deal with one persistent drawback -- their vulnerability to rust and corrosion.
Without the proper precautions and protections in place, a metal roof will quickly fall victim to damaging rust and corrosion as it is exposed to rain and moisture, savagely curtailing its longevity and potentially leading to annoying (and costly) leaks. However, rust problems with your new metal roof are far from an inevitability, and there are a number of relatively simple steps you can take to prevent your metal roofing falling victim to corrosion:
Buy a rustproof roof
Obviously, rust won't be a problem if your roof is made out of a metal that doesn't rust. In years gone by, this meant turning to copper or lead roofing, but these options are generally impractical (not to mention cripplingly expensive). Aluminium roofing, however, is a far more viable prospect; while generally significantly more expensive than steel roofing, and slightly less durable, the extra longevity and low maintenance aluminium provides can make aluminium roofing a very attractive investment.
Apply a rustproof coating to your roof
If you do opt for steel over aluminium, applying a durable rustproof coating to your roof can give it rust-resistance and longevity rivalling that of aluminium. You have a number of options to choose from here:
- Galvanised coatings are very inexpensive, and consist of a thin layer of zinc which corrodes in place of the steel beneath (a phenomenon known as cathodic protection). No colour options are available, and the coating will have to be reapplied periodically.
- Rustproof paints are another inexpensive option, but tend to be more difficult to apply unless you purchase pre-painted slats. However, they come in an enormous variety of colour options, and can be reapplied with relative ease when they start to degrade.
- Powder coatings are some of the most expensive coating options, but for your investment you get an enormously durable and effective coatings capable of protecting your roof for many years to come. Colour options are available, but tend to be limited.
Insulate your roof
Protecting your roof from rain and outside moisture is all well and good, but won't be very useful if the underside of your roofing corrodes due to condensation. Differing levels of heat and humidity between the interior and exterior of your building can cause condensation to collect in large quantities on the underside of metal roofing, leading to rapid rust if the problem is not guarded against.
Closely regulating your building's internal heat and humidity can help with these problems, but a more simple and permanent solution is installing insulation on the underside of your roofing. As well as providing a physical barrier between your roof and internal moisture in your building, the insulation prevents the underside of the roof from becoming significantly warmer than the exposed top, preventing condensation from collecting there.