Metal roofing has entered the mainstream and is a viable option for nearly all homes, except those with very flat roof pitches. Not all metal roofs scream "metal." There are now shingle-style metal roofing products that are almost indistinguishable from traditional asphalt shingle roofs. If you are wondering about the merits of metal roofing, here are 12 things to know.
Metal Roofs Are Not Just a Novelty
Once, metal roofing was found only on high-end, architect-designed homes. That's no longer true. Metal roofingis found in conventional houses, thanks to increasing availability and improved manufacturing processes. According to industry statistics published in 2017, market share for metal roofing increased at a rate of roughly three percent each year for a few years and about 15 percent of all roofing installations used metal roofing materials. At the same time, the market share for asphalt shingle roofing fell, and accounted for about 59 percent of the total roofing installed.
Everything You Need to Know About Metal Roofing
Metal Roofing Can Be Installed Over Existing Roofs
Metal roofs can be installed over your existing roof without tearing off shingles, provided local building codes allow it. While shingle removal is the preferred route, tear-off is messy and raises the cost of the job.
A potential problem with this type of installation is trapped water vapor. If trapped between the metal roofing and old roofing, moisture can build up and cause mold and rot. But roofers can install a vented metal roof that eliminates this potential problem. Or, installing the new metal roofing over furring strips (1 x 3s or similar) will raise the metal and provide a ventilating air pocket between layers.
Make sure to consult local building codes before having a metal roof installed directly over old shingles. Some jurisdictions may require full tear-off whenever a new roof is installed.
Metal Roofs Are No Noisier Than Asphalt Roofing
Although it's a common misconception that metal roofs are noisy when rain or hail falls on them, the reality is that when properly installed, metal roofing is no noisier than any other type. Metal roofing is typically installed over a solid substrate. Additionally, the attic and insulation provide a sound barrier. From interior living spaces, inhabitants rarely notice any increase in sound levels when a metal roof is installed.
Metal Roofing Does Not Attract Lightning
You might think that a metal roof will attract lightning, but this is not borne out by facts or statistics. According to a technical bulletin from the Metal Construction Association, "Metal roofing does not in any way increase the risk of a lightning strike." Not only that but also if metal roofing does happen to get struck by lightning, it is less combustible than conventional roofing materials such as wood shakes or shingles.
As the bulletin asserts, "Because metal roofing is both an electrical conductor and a noncombustible material, the risks associated with its use and behavior during a lightning event make it the most desirable construction available."
The reason that metal roofs do not attract lighting is simple: lighting seeks a path to ground, which is why trees, telephone poles, and other such structures tend to attract lightning. Metal roofs are isolated structural components, with no direct path to ground inherent in their design. Hence, there is no scientific reason for lighting to strike a metal roof any more often than it strikes an asphalt shingle roof.
Metal Roofing Can Be More Cost-Effective
Although most metal roofing products carry warranties comparable to the very best asphalt shingles (about 30 years), in practice, metal roofs have been known to last 50 years or more. According to State Farm Insurance statistics, metal roofs routinely have a longevity of 40 to 70 years. It is therefore very rare for a homeowner to install more than one metal roof over the time he or she lives in the home.
By contrast, a homeowner will likely replace an asphalt shingle roof two or even three or four times over a 50-year period. Overall, while the cost of a metal roof is more expensive than asphalt roofing (about double), it can save money over a long period.
Many insurance companies may also offer reduced rates to homeowners with metal roofs, particularly in wildfire or hail prone areas, further reducing overall costs.
Metal Roofing Is Impervious to Fire, Rot, and Insect Damage
One of the principal reasons metal roofing has exploded in popularity is that it is virtually fireproof. With the dangers of wildfire on the rise, metal roofing has become the roofing material of choice in many parts of the country. And not only that:
- Insects such as termites can never eat metal roofing.
- Metal roofing is impervious to rot and mildew.
- Since it conducts heat quickly from the sun, snow slides off more quickly than with conventional roofing.
Metal Roofs Are More Energy-Efficient
Industry studies show that metal roofs reflect solar radiant heat, which can reduce cooling costs by 10 to 25 percent. In climates where cooling costs are higher than heating costs, coating a metal roof with a shiny or granular coating can maximize the reflective capacity of the roof and improve energy savings.
Metal Roofing Can Work on Roofs With Low Slopes
It's often believed that metal roofing is suitable only for roofs with a steep slope, but standing-seam metal roofing can work fine on gently pitched roofs. This type of roofing is installed in large sheets with seams that are raised and sealed tightly together to resist water. While some slope is necessary to ensure water run-off, most homes can accept metal roofing.
Severe Hail Can Ruin Metal Roofing
Although metal roofs are considerably more durable and maintenance-free than asphalt shingles and other forms of roofing, they are not indestructible. There is one weather condition in particular that bodes ill for metal roofing: large hail. Aluminum and copper, in particular, can be susceptible to denting when hailstones approach golf-ball size.
Steel is harder and fares better in hailstorms, but if you live in a region where such catastrophic hail can occur, be aware of this when considering metal. Pea-sized or even dime-sized hail is rarely a problem, but hailstones larger than this have been known to ruin metal roofs.
Then again, large hail can also destroy an asphalt shingle roof, so if you make sure to have good homeowner's insurance that covers such storm damage, there is no reason not to install metal roofing.
Installation and Repair Usually Requires a Professional
DIYers have been known to install and repair metal roofing, but it is generally not advised. Metal roofing is generally available only through select retailers, and the techniques for installation and repair are specialized skills. If you opt for metal roofing, you will likely be calling a specialist should problems occur. Fortunately, such problems are rare with metal roofs.
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Ridge Vents Are More Obvious
On most homes today, attic venting is provided by a continuous ridge vent that runs across the peak of the roof. On a shingled roof, this continuous ridge vent (CRV) is a strip of shingle-like material that runs the entire length of the peak of the house, masking outflow holes on the sides of the ridge. You likely have seen this countless times, but probably never really noticed because the CRV usually lies very flat and blends in perfectly with the surrounding roof.
On many metal roofs, especially standing-seam roofs, the CRV is also metal, and it stands out further and is thus much more noticeable. These thick, prominent lines or ridges are inherent in metal roofs and add to their distinctive look.
Metal Roofs Are Recyclable
Although metal roofs are very long-lasting, when the time comes to replace one, the old metal is readily accepted at metal recycling outlets. Old asphalt roofing, on the other hand, is usually destined to take up space at a landfill.
Metal Roofing Is Impervious to Fire, Rot, and Insect Damage
Insects such as termites can never eat metal roofing. Metal roofing is impervious to rot and mildew. Since it conducts heat quickly from the sun, snow slides off more quickly than with conventional roofing.
Considerations for Both Options. Your local roofing contractor may recommend tearing off your old shingles before installing a metal roof if any of the following conditions apply: Rough or uneven asphalt shingle roof will affect the metal roof's appearance. The deck sheathing show signs of rot and would require repairs ...What is a negative aspect of a metal roof? ›
CON: Metal roofs can be noisy.
Sure, metal could be noisier than other types of roofing, especially during a heavy rain or thunderstorm, but extra layers of solid sheathing or insulation installed beneath it will typically minimize the sound heard inside.
These are some of the areas where a metal roof is most prone to leakage, partly because stack flashings have a lifespan of less than half that of the roof itself. Metal roofs are prone to expanding and contracting due to heat, and this puts a lot of strain on stack flashings over time.How many years does a metal roof last? ›
The average metal roof will last between 40-70 years. Some materials, like copper roofing, will last even longer — with some copper roofs dating back over 100 years. There are also a number of factors that can increase the longevity of your roof, as well as decrease it.Why not put metal roof over shingles? ›
When installing a metal shell over a shingle roof, you may have broken decking boards or rotting you can't see. A metal roof will add some weight to your roof that your decking must hold. If your decking's integrity is compromised, the added weight of a metal roof can cause structural damage to your roof and home.How long should a metal roof last? ›
Metal roofs will typically last 70 to 100+ years, depending on the material used. Metal roofs can withstand harsh weather conditions better than most other roof types. Metal roofs are environmentally friendly. Regular asphalt shingles use petroleum products and depend on fossil fuels to create the final product.Why don t people use metal roofs? ›
If they're so great, why doesn't everybody put a metal roof on their home? Higher Initial Cost: Metal roofs are typically more expensive than traditional asphalt shingle roofs, which can deter some homeowners from installing a metal roof.Do metal roofs make house hotter? ›
Metal roofs do not make a house hotter than any other kind of roofing material. In fact, they can actually help to keep the home cooler during the summer months. Metal roofing is one of the most energy efficient materials available to homeowners and can help lower the energy used to cool off your house.Do metal roofs leak more than shingles? ›
Do Metal Roofs Leak More Than Shingles? If installed incorrectly, metal roofs have the potential to leak more than shingles. However, if you find an experienced contractor who can install it correctly, metal roofs shed snow and ice to prevent moisture buildup.
On Average... The average metal roof will last between 40-70 years. Some materials, like copper roofing, will last even longer — with some copper roofs dating back over 100 years. There are also a number of factors that can increase the longevity of your roof, as well as decrease it.