Pros and Cons of Metal Roofing

A Detailed Look at the Pros and Cons of Metal Roofing

If you're thinking about purchasing and having a metal roof installed on your home, it is very important that you look at the pros and cons of a metal roof against other roofing materials, including tile, wood and asphalt. Here is a look at the advantages and disadvantages of metal roofing:

Benefits of Metal Roofing

There are a number of ways that metal roofing is better than other more conventional types of roofing materials.

  • Expected Life - When installed properly, metal roofs can last as long as -- if not longer than -- the house. They can survive high winds, seal out water, and shed snow. This type of roofing material is also resistant to rot, insects, mildew, and fire. The warranties for metal roofs can vary greatly, but the majority of companies are known to back their metal roofing products for between 30 and 50 years. Metal roof paint finishes tend to have limited warranties for approximately 30 years.
  • Weight - Metal roofing is considered to be lightweight, weighing somewhere between 50 and 150 pounds each square. Many people think metal is heavy, but this is a myth. This is particularly true when you compare it to other roofing types, such as tile and concrete tile, which weighs about 750 and 900 pounds each square respectively. Depending on the type of metal roofing material that is being used, you may be able to use it over the current roof without needing to add extra structural support. This can help reduce or downsize the amount of support members needed.
  • Ease and Speed of Installation - As a general rule, metal roofing materials will come in panels that are between 12- and 36-inches wide or multiple-shingle sections. These can be installed quickly if being installed by an expert contractor. Due to the metal being so lightweight, it is easy to install as well.
  • Fire Resistance - Due to the fact that metal roofs are noncombustible, metal roofs usually have the highest resistant fire rating (Class A). However, the overall classification of the roof will depend a lot on the materials that are beneath the roof's surface that could potentially ignite under the right circumstances. Typically, metal roofs are installed over a flammable material like wood shingles, which have a Class C rating. For more information regarding problems that could arise during a potential house fire, look under the "Drawbacks" section a little later in this article.
  • Minimal Roof Pitch - For the most part, materials for metal roofs are able to be installed on roofs with a slight pitch without having to worry about potential leaks. The minimum roof pitch for a metal roof is 3-in-12, which is where the roof will rise 3 inches for every horizontal foot.
  • Heat Conduction - Metal throws back (reflects) heat from the sun, which helps to reduce heat gain during the day. What this means for you is that you can save energy on air conditioning. While the material is low in R-value insulation, many metal roofing systems make use of a space with dead air between the roof deck and metal in order to improve energy efficiency.
  • Maximum Shedding of Snow and Rain - Metal roofing materials are virtually impervious to snow and rain due to the way that each panel interlocks with one another and because of the hard, slippery surfaces.

Drawbacks of Metal Roofing

While there are many benefits to metal roofing, there are also a few downsides that need to be mentioned. Luckily, manufacturers of metal roofing materials have upgraded their products so that most of the below concerns have been addressed or solved:

  • Cost - One of the biggest disadvantages to metal roofing is the cost associated with it. Like other high-quality materials, it costs anywhere from between $150 and $600 each square, which is equal to 100 square feet. Due to metal roofing's long-term resilience, you will be able to save the difference in cost (and probably more) in the long run if you are going to be staying in your home. Plus, you will save money on seasonal upkeep. However, if you are going to be moving in a few years, then you won't realize the return on your investment.
  • Denting - A metal roof has the ability to dent if big enough hailstones hit it. Copper and aluminum are more susceptible to denting since they are softer than steel. However, there are some types of metal roofing that are guaranteed to not dent.
  • Noise - Some people complain about the noise of metal roofing, such as when it rains. While some say that the sound is romantic, others say that it sounds like they're living inside of a drum that someone is beating on. However, when you think about it, it is obvious that it will be noisier during a rain or hailstorm under a metal roof than a shingle or tile roof. Today, though, there are some materials that can be used to help minimize the noise, such as solid plywood sheathing and sound-deadening insulation.
  • Expansion and Contraction - Since metal will expand and contract when it heats up and cools down, most metal roofing products will come with a fastening system that accommodates movement. Without it, fasteners will come loose and the roofing won't be secure. On hot days, expansion and contraction of the roof can result in a wavy effect.
  • Modifications - Large metal roofing panels are more problematic to replace than single shingles if they are damaged. In addition, if you decide to renovate or add a room onto your home a decade or two down the road, it could be hard to exactly match the metal roofing material.
  • Lightning - It is often assumed that due to the fact that metal conducts electricity that metal attracts it as well. However, this isn't exactly true, and there is evidence that shows lightning strikes high objects, such as trees, close to metal roofs instead of the metal roofs themselves. However, if you are worried about it, it is possible to have a lightning protection company to ground your metal roof -- for a price.
  • House Fire - While metal roofs work well to protect your home against a fire that is approaching the exterior of your home, they don't do much if a fire starts on the interior of your home. If the fire is severe, it may require for the firemen to cut through your metal roof in order to put the fire out, which makes things more difficult on the firemen and lengthens the time it takes to put the flames out.
  • Marring and Care - There are some painted roof finishes for metal that can fade, chip, peel, chalk or scratch, but almost all of them have a 30-year guarantee. If you walk on metal roofing, or at least some types of them, such as those with a granulated-stone surface, it could cause wear. Panels need to be treated with extreme care during and after installation so as to not to dent or scratch the roofing. It is often necessary to hose the metal roofing down so that it continues to look nice.

For more information on the benefits and drawbacks of metal roofing or to schedule an estimate, contact us at Magnolia Group today.