Pros and cons of metal roofs
Updated: 2022-01-12
By Paul Bianchina
If the time has come to invest in a new roof, it might be worth taking a close look at metal roofing as an option. Metal roofing is far more attractive than you might think and is available in a surprising number of colors and patterns. And while it is a more expensive option than many other types of roofing, you'll enjoy the benefits of a roof that is virtually maintenance free and that will probably last the life of house. For most people, it truly is the last roof they will ever have to buy for their home.
Besides its durability, metal roofing has some other advantages as well. In areas with cold winters, snow and ice tends to slide off the roof much more readily then it will with other types of roofing, preventing potentially dangerous snow buildups. And since a typical metal roof installation has virtually no horizontal seams, problems with ice damming are eliminated. This lack of horizontal seams also makes metal roofing ideal for low-pitched roofs, and it will work very effectively on roofs with pitches down to three in 12, and sometimes even less.
Most metal roofing applications are also relatively lightweight, when compared with other types of roofing. If you have an existing home that needs a new roof, in many cases metal can be installed directly over your old shingles without concerns about structurally overloading the existing framing, which saves you the cost of removing and disposing of the old shingles. Metal roofing is also very fire resistant, and carries the highest fire rating - something that may even help with your homeowner's insurance rates.
A couple of the advantages of metal roofing can also be disadvantages. Its ability to rapidly shed large amounts of snow and ice can be a danger, particularly with homes with steeper pitched roofs in areas that are prone to high snowfalls. To minimize snow-slide problems, most installers will add snow guards, which are bars, clips or other products specifically designed to break the snow up as is settles on the roof and as it slides off, causing it to fall to the ground in small pieces instead of large heavy chunks.
Another concern about metal roofing is the potential for noise in a rainstorm. Metal sheets will certainly reflect a lot more noise then other types of softer, denser materials such as asphalt or wood shingles, but this noise is greatly reduced by installing the metal over solid sheathing such as plywood, and when installed over a well-insulated attic, rain noise on metal is rarely a significant problem.
Besides its durability, metal roofing has some other advantages as well. In areas with cold winters, snow and ice tends to slide off the roof much more readily then it will with other types of roofing, preventing potentially dangerous snow buildups. And since a typical metal roof installation has virtually no horizontal seams, problems with ice damming are eliminated. This lack of horizontal seams also makes metal roofing ideal for low-pitched roofs, and it will work very effectively on roofs with pitches down to three in 12, and sometimes even less.
Most metal roofing applications are also relatively lightweight, when compared with other types of roofing. If you have an existing home that needs a new roof, in many cases metal can be installed directly over your old shingles without concerns about structurally overloading the existing framing, which saves you the cost of removing and disposing of the old shingles. Metal roofing is also very fire resistant, and carries the highest fire rating - something that may even help with your homeowner's insurance rates.
A couple of the advantages of metal roofing can also be disadvantages. Its ability to rapidly shed large amounts of snow and ice can be a danger, particularly with homes with steeper pitched roofs in areas that are prone to high snowfalls. To minimize snow-slide problems, most installers will add snow guards, which are bars, clips or other products specifically designed to break the snow up as is settles on the roof and as it slides off, causing it to fall to the ground in small pieces instead of large heavy chunks.
Another concern about metal roofing is the potential for noise in a rainstorm. Metal sheets will certainly reflect a lot more noise then other types of softer, denser materials such as asphalt or wood shingles, but this noise is greatly reduced by installing the metal over solid sheathing such as plywood, and when installed over a well-insulated attic, rain noise on metal is rarely a significant problem.
"Metal" is obviously a very generic term. In actual usage for roofing, metal can refer to steel, aluminum, copper, and even stainless steel. Copper, which goes on shiny and then weathers naturally to a green patina, is one of the oldest metals used for roofing. Still used in some high-end applications today, its beauty is offset by the disadvantage of prohibitively high cost. Stainless steel, which will not rust or corrode even under the harshest conditions, likewise is prohibitively expensive for all but the most demanding applications.
For residential applications, aluminum is fairly common. It is lightweight, rustproof and is especially suitable for forming into shingle patterns. For the most part, however, when you talk about metal roofing you are talking about steel, which is both heavier and sturdier than aluminum, and is the most common material for most residential and commercial applications. Both aluminum and steel are coated with a baked-on primer and then a finish coat of paint in one of about 10 standard colors. Many manufacturers also offer custom colors by special order.
Metal roofing is also rated by the gauge of the metal, which refers to its thickness. In another of those oddities of construction life, the larger the gauge number is the thinner the metal will be. Most metal roofing is in the 26- to 29-gauge range, with 26 gauge being thicker and heavier, and also more commonly available.
Metal roofing comes in two basic forms - shingles and sheets. Singles may be individual pieces or may be longer strips that are stamped to look like several smaller shingles. The shingles may have the appearance of slate tiles, wood shakes or ceramic tiles, and come in several colors.
More common are the sheet styles, which range from 12 to 36 inches or more in width. The individual sheets are custom-cut to the ridge-to-eave length of your roof, or they may be fabricated right on-site. Either way, installation is fast in comparison to other types of roofing, and there are a number of matching ridge caps, end caps, valley flashings and other components to finish off and weatherproof the installation.
Metal roofing material and installation prices can vary widely with the type, style and color of the metal and the complexity of the roof. If you're interested in a new or replacement metal roof, talk with at least two suppliers or licensed roofing contractors, compare their product offerings and ask for a couple of recent local references so you can see the roofing installed and talk to their customers.
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