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Can I Install a Metal Roof Over My Old Roofing System?

December , 2023 | 8 min. read

By Joe Martinez

metal roof on modern home

Roof replacements are a big deal. It’s one of the biggest investments you’ll make for your home, so you want to make sure it’s done right the first time around. There are many reasons homeowners opt for roof replacements, ranging from age and damages, to simply wishing to add more curb appeal to their home. If there’s one thing people who have undergone a roof replacement in the past know, it’s that sometimes they can be a hassle. Really? Who would've thought?

If only there was a way to install a new roof over the pre-existing one, wouldn’t that be nice?

Well, folks, I have good news for you. You can install a new metal roof over your current roofing system, and the process is called a roof overlay. At RoofCrafters, we’ve been assisting homeowners like you with their roofing projects for nearly 30 years, in turn saving them thousands of dollars, all while giving their homes a botox-free facelift.

Roof overlays are commonly completed with metal roofing materials, adding aesthetics, insulation, and functionality. All without having to do a complete tear-off. If you’re curious if installing a new metal roof over your current roof is possible, you’ve come to the right place. In this article, you’ll learn how a metal roof can be installed over an old roofing system, how much you’ll need to borrow from your piggy bank, and the benefits of a roof overlay.


So, let’s get started!

Can a Metal Roof Be Installed Over an Old Roofing System?


In nearly every case a homeowner asks if a metal roof can be installed over their current roofing system. The answer is usually yes. This is on the list of the many reasons why metal roofing continues to grow in popularity. The installation of a metal roof doesn’t require a complete tear-off, which oftentimes is an expensive and timely job. Instead, the lightweight properties of metal allow it to be installed directly onto the pre-existing roof, helping you save on money and time. 

Concealed Fastener being installed on standing seam metal roof

Metal weighs less than a pound per square foot, making it a doable option for a roof overlay. Although this won’t add a significant amount of weight to your roof, if you have multiple layers of roof underneath your current system, assessments will need to be made to ensure that your home can support the overlay.

roofers installing a screw-down metal roof off a ladder

Besides saving on the costs of a complete tear-off and roof replacement, your metal roof overlay provides the benefit of additional insulation. Metal roofs are heat blockers, meaning they reflect solar heat as opposed to absorbing it, keeping your home cool in the summer and warm in the winter. While a metal roof overlay sounds like a dream come true, if your roofing contractor deems it nonsensical, you may need a roof tear-off. 

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When to Opt for a Roof Tear-Off in Your Metal Roof Installation



Sometimes, if the metal roof layover will result in too much additional weight, or the preexisting roof has too much damage, a roof tear-off is necessary. In most cases, the existing roofing has rotten plywood decking that needs to be repaired before the new metal goes on.

rotten wood on a roof-1

A roof tear-off is the complete removal of all the old roofing materials on your roof. During the tear-off process, your roofing contractor will go over your existing roof and remove the old roofing materials section-by-section to prepare for your new roof installation.

roof being torn off and one piece of plywood being replaced

This tear-off process allows the roofing contractor to see the overall condition of the wood decking and if any wood is bad, they can identify it so that it can be replaced before installing your new roof. Even when we can overlay, we'd still recommend a complete tear-off for the best installation!

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Mastering Metal Roof Overlay: Techniques for Installing Over an Existing Roof


There are a few different ways that a roof overlay can be done. One of the most popular installation methods involves building a grid to attach the new metal roof. Which is done by putting down 1 x 4 metal or wood purlins. In English, a metal purlin is a lightweight bar or beam that is used for structural support. From there, it’s as simple as installing the panels and all of the flashing.

Wood nailers being installed on a roof

It’s important to keep in mind that with the added costs of the grid materials and installation, the final price can be similar to tear-off. In some cases, roofers will install the new metal roof directly onto the existing roofing system. However, with this plan of action, it’s important to put down some sort of underlayment over the shingles to prevent the granules from damaging the new metal material. 

Calculating the Cost: What to Expect for a Metal Roof Overlay Investment



While you’ll get to save a little change on demolition and waste costs, remember that the roofing contractors will still be building your roof on an entirely new grid, and possibly making repairs to the pre-existing roof.

metal roof overlay

The cost of your project will depend on the size of your roof, how many repairs are necessary, how much wood is needed, the linear feet of purlins laid, as well as labor. That being said, the average cost of a metal roof overlay is anywhere between $6.75 to $ 9.25 per square foot. 

Exploring the Advantages: Key Benefits of Opting for a Metal Roof Overlay


Saving money is the most thought of benefit, right? But, a metal roof overlay can be beneficial to homeowners in other ways, including:

Longevity: A metal roof overlay can add 50 years or more to the lifespan of your roofing system before it needs to be replaced. Which makes this roofing choice one that will last. 

Strength: Metal roofs have proven time and time again to be one of the strongest roofing materials. They withstand the most unfavorable weather conditions, from intense winds and rain to scorching summer heat. 

Low Maintenance: Due to their strength, metal roofs don’t require regular or expensive repair jobs. They remain sound year after year. That being said, do not neglect your bi-yearly professional maintenance routine. 

Insulation: As previously mentioned, metal is a heat blocker. It reflects solar heat instead of absorbing it. You can trust that your home will be cooler in the summer, not to mention a reduction in your electric bill. Hallelujah! 

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Making the Decision: Is a Metal Roof Overlay the Right Choice for Your Home?


A metal roof overlay is a good option for homeowners who want to improve their home's look and durability. It's cheaper and less work than getting a whole new roof. It stands out as an excellent option if you're seeking to reduce energy expenses and extend your roof's lifespan.

Yet, it's crucial to weigh this option against the current state of your roof. If your roof already bears excessive weight or has significant damage, an overlay might not be the most suitable or safe choice.  If you’d like to know more about installing a metal roof over your pre-existing system, your best plan of action is to get in touch with a professional roofing company.

A skilled roofing contractor will be able to help assist you with an inspection and let you know if an overlay is a possibility. If you’re struggling to find the best contractor for the job, be sure to download “The Top 10 Most Critical Questions You Want to Ask Your Potential Roofing Contractor”.

image call to action, download the top 10 checklistThis checklist includes several different prompts to ask your roofer to prepare you to hold the company accountable for its quality of work and services when it comes to your roof overlay. In the meantime, if you’re looking to learn more about roofing overlays and tear-offs, check out our article, “Roof Overlay Vs. Roof Tear-Off: Which is Better?” to better understand their key differences. 

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Joe Martinez

At RoofCrafters, our mission is to provide job opportunities for others to thrive and grow while making a meaningful impact within our communities.