Can I Install a Metal Roof Over My Old Shingles

By: Chuck Magee | March 2021 @ 3:07 pm

Can I install a metal roof over my old shingles? Kreunen Construction of Olive Branch, MS answers these questions. Metal roofs provide a series of extraordinary benefits over asphalt shingles roofing. Some years ago, they were an innovation. Now, thanks to their durability and energy efficiency, they have become an extended roofing option across the US.

However, their installation costs make some homeowners think twice before deciding to install them. That is why many of them wonder: Can I install a metal roof over my old shingles?

Can I Install a Metal Roof Over My Old Shingles

Initially, the answer is yes. It is something possible. But, if you plan to make this switch, you should know how it is this process. Besides, consider some important implications that may turn this project into a bad idea.

Don’t worry; we are here to bring you the answers you need.

Why Not Install a Metal Roof over Shingles

It may look like a simple job to install a metal roof on top of shingles. Though, every roofer knows that installing metal roofs is a demanding job. You need to have experience and skills with metal roof installation, and if you don’t, you must call a professional. By doing so, you can ensure that your new metal roof will not give you problems later.

First, you can install a metal roof over asphalt shingles if the old one has less than four shingles’ layers. In this sense, you’ll need to check your local building code since the standard may vary by area.

The roofer will build a slat board base over the shingles. This base will support the metal roofing panels. So, this slat board will have lengthwise furring boards lying every two feet along the roof. Then, your roofer will fasten them to the roof from the bottom up to the top of it with 3-inch wood screws.

Following this, they will install metal ending around the roof border and metal sheets on the frame. Your roofer should attach them one at a time with screws leaving a two-feet space between them. Each sheet will overlap the previously installed sheet.

Once the attached metal panels cover completely the roof, comes the step of installing metal trim in the top ridge and roof edge. Here, the roofer will put a notch in the middle of the metal using notching scissors to bend it over the ridge.

As the last step, the roofer will seal openings with self-adhesive or closures. This measure will prevent debris, pests, and moisture from entering under your metal roof.

This method seems to be failure-proof, isn’t it? However, we have news for you.

The Cons of Installing a Metal Roof over Shingles

Some significant problems may appear after installing a metal roof over shingles. Next, we will show you in detail the reasons why you should remove your old shingles before installing a metal roof.

  1. It is difficult to inspect – Your new metal roof will need a solid foundation. This base will be the wooden deck under your old roof. So, if you install a new metal roof over the shingles, your roofer will not be able to check your roofing deck condition.

Only by completely removing the old shingles you will know if there are issues like rotten wood. If problems like those exist in the deck, you will have to rebuild the entire roofing system.

  1. It can generate an uneven surface: The furring boards the roofer place over the old shingles may create an uneven surface. These boards can absorb humidity from the environment and get bend over time. So, it may deform your metal roof with the pass of time.
  2. It can reduce your metal roof’s useful life: Installing a metal roof over shingles may not be the best decision. But, to do that without laying a wooden base where to build on is even worse! And some non-professional roofers do that.

When affixing metal roofing panels directly to shingles, the asphalt granules will wear the metal roofing coating reducing its lifespan.

Installing a metal roof is a significant investment. So, cutting corners looking to reduce costs, and time in projects like these, will bring you costly problems later. Moreover, it will reduce the value of your roofing system as well as of your property.

In conclusion, the best you can do is to remove the existing shingle roofing system. Later, you can install your new metal roof correctly.

Advantages of Installing a Metal Roof

Among the roofing materials available in the market, metal roofing is one of the best choices you can make. It offers you the following extraordinary benefits:

  • Energy efficiency: If we compare it with other materials like, for example, asphalt shingles, metal roofers provide the best results keeping your indoor temperatures at comfortable levels. They will keep your home cool during summer’s hottest days, thanks to their reflective properties. Besides, their reflective coatings increase their capacity to cooling your home. You can obtain up to 20 percent of savings in cooling costs since your AC unit will consume less energy to cool your home indoor.
  • Wind and Fire Resistant: Electric storms and lightning can cause fire damage. But, the best defense your house may have against these natural phenomenons is a metal roof since they are fire-resistant. With an asphalt shingles roof, you’ll always have the risk of fire by causes like this.

On the other hand, the overlapping and interlocking of the metal sheets give metal roofing high wind resistance.

  • Durability: Metal roofs have no rivals when it comes to durability and resistance against weather effects. Other roofing materials, including asphalt shingles, will lessen their value as they age. They suffer wear and tear much faster due to the weather elements exposition. With a life expectancy of over 50 years, you will seize the long-lasting benefits that a metal roof provides.
  • Adaptability:  Metal roofing manufacturers offer a variety of products that satisfy both aesthetic and using requirements. You can find a wide variety of designs that mimic wood, slate, tiles, slate, and shingles’ appearance. Also, metal roofs can meet both residential and commercial needs. So, regardless of the architectural style and the nature of your property – commercial or residential – metal roofs are highly adaptable.
  • Lightweight: Metal roofing is the lighter roofing material for homes. A weighty roof will damage more and more your home structure and foundation as it gets older. In this sense, metal roofs help to avoid structural movements and damage related to this since they are lightweight. It is critical in those areas prone to earthquakes.

The Cost of Installing Metal Roofs

Metal roofing installation is a physically hard task. It demands capable and highly experienced roofers to perform the installation correctly. Since you are employing a more expensive material, the installation costs may be one of the highest of the whole project.

Still, the excellent benefits that a metal roof offers are worth the investment.

Are You Ready to Upgrade Your Roofing?

Do you want to switch from shingles to a metal roof? Trust the Kreunen Construction expert team for that job. Our products have a Class 4 distinction in impact and a Class A fire rating. So, they can resist a wide range of damaging forces.

They last much more than slate, wood, and shingles. Moreover, they are algae, rust, and mold resistant.

Your metal roof from Kreunen Construction will last a lifetime.

Contact Kreunen Construction at 901-763-8506 or online today to get a quote. At Kreunen Construction, we serve Olive Branch, Southaven, MS, and all of Memphis, TN.

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