Can You Install a Metal Roof Over Shingles?

Yes, you can install a metal roof over shingles, making it a popular choice for homeowners looking to upgrade without the hassle of removing the old roof. This method can save time and reduce costs. However, it’s essential to ensure the existing roof is in good condition and meets local building codes.

Are you ready to replace your existing roof with a new metal roof? Typically, you would expect to have your old roof fully removed before that new roof can be installed. Can you actually install that roof without removing the shingles first?

Let’s take a look.

Can You Install A Metal Roof Over A Shingle Roof?

The short answer is that you absolutely can have your metal roof installed over the top of the existing shingle roof.  It may not always be possible to do so, and we will get into that later. However, there are lots of benefits to actually just having the metal roof installed over the roof that is already on your home.

One of the biggest reasons why homeowners do this is to save on labor costs. As you can expect, re-roofing your home is one of the most expensive home improvement jobs you can have done. There aren’t many ways to cut back on costs without compromising on quality, but depending on your home, this is a good way to save money and still get the full value from a metal roof.

You will also see that having the roof installed over the existing shingles means that the installation process is a lot quicker too. That means less disruption at home while the installation is taking place, so you can start enjoying your new roof quicker.

Eco-Friendly Bonuses To Re-Roofing Your Home

Something you will be thinking about when replacing your roof, is the ecological impact of doing so. More homeowners want to carry out renovations without having a drastic impact on the planet, and the good news is that placing a metal roof over an existing shingle roof does have some ecological benefits.

Once that metal roof is installed, you will be able to enjoy extra insulation against the weather. That allows you to keep your home at a comfortable temperature while spending less on energy to do so. With so many people looking to reduce their household bills, this is actually a great way of doing so.

Also, this method of roofing your home is more eco-friendly because the old asphalt shingles are not being removed and thrown away. They are still serving a purpose in your roofing structure, so keeping them out of landfills will benefit both you and the environment.

When You Shouldn’t Install A Metal Roof Over Shingles

As you can see, there are lots of benefits to simply installing that new metal roof over your old shingle roof. However there are some times when you should not be doing this, and should instead fully remove the old roof to install the new one.

Building codes prevent re-roofing: The first thing you should check if you are considering installing your new roof over the old one, are the building codes for your home. You want to see if these codes will allow you to carry out this practice. Many buildings will allow for it, but in some cases you will find that local codes will not allow for two layer roofing on any structure.

It’s essential that you check this before you even get in touch with your local roofer, as if you don’t and it turns out your building codes do not allow for this, you could be on the hook for a fine. 

Your new roof warranty doesn’t allow it: Something that also should be checked is the warranty on the new metal roof you are installing. Warranties will be slightly different, depending on the manufacturer of the roof that you are buying. In some warranties, you will see that they are voided if you install them over asphalt shingles.

If your new warranty does not allow it, then you will need to have that asphalt shingle roof removed. If you are set on leaving the shingles in the place, you will need to look for another metal roof from a different manufacturer that will allow for this. 

There are problems with the shingle roof: If you are looking at replacing your roof, then the old roof may well have some problems that weren’t solved with minor repairs. For example, if it has leaps, then there may be water damage in the roof, and this will worsen over time, even if you have that metal roof installed.    

Also, you do need to consider whether your house can support the weight of two roofing systems. If your roof is already showing signs of struggling under the weight, such as sagging roof decking, then you may not be able to place a metal roof over the existing system.

If you are not sure if your existing roof is in good condition, then you can ask your local roofer to inspect it and advise you on what to do next.

There are moisture issues in the existing roof: Moisture is the number one enemy of any roof, and many people will be having a metal roof installed because they are so good at resisting water. However, no matter how good that metal roof is, it cannot stop the damage from moisture if it is already trapped in the existing asphalt shingle roof.

Again, inspecting the insisting roof first is going to be vital. You need to look for any signs of moisture damage, such as mold, rotting wood, or water stains on ceilings and walls in your home. If you are seeing any of these signs, then that shows that the existing roof is not in good shape and does need to be removed. Your roofer will be able to advise you further on whether your asphalt shingle roof can be left in place before they install your new metal roof.

Conclusion

Installing a metal roof over a single roof is something that you absolutely can do, and has a lot of benefits for your home.  Not every home can support to roof layers though, so talk to your roofer about whether you can have that new roof installed directly over the old one.

If you live in Virginia areas such as Warren, Fairfax, Winchester, or Leesburg, Piedmont Roofing will be happy to help you with your roofing needs.