When it comes to installing a new roof, we know this can be a costly investment. This leads many homeowners searching for shortcuts or ways to save money where they can. One way we see this present itself is when homeowners opt to install a metal roof over shingles.
While installing a metal roof over your existing asphalt shingles is possible in some situations, we do not recommend this. In fact, there are quite a few problems with this. In this article, we discuss 5 Issues with Putting a Metal Roof Over Shingles, so you can make an informed decision regarding your roofing needs.
Table of Contents
– 5 Issues with Putting a Metal Roof Over Shingles
– Roof Decking
– Roofing Components
– Future Leaks and Repairs
– Addressing the Original Problem
– Finding the Roof That’s Right for You
5 Issues with Putting a Metal Roof Over Shingles
If you’re here, you may be thinking about installing a metal roof over your shingles. At Elite Exteriors, we believe in educating homeowners when it comes to their roof, so they can make smart decisions for their new roof investment. Keep reading and learn about the 5 issues with putting a metal roof over shingles.
If you’re wanting to install a metal roof over shingles, let’s talk about roof decking. Roof decking is basically wooden boards that are installed under your shingles, making up the foundation of your roof system as a whole. This roofing component is vital to the health and longevity of your new roof.
During a roof replacement, your contractor will tear off your old roof, all the way down to its decking. This gives the roofer a chance to inspect the decking, and see if there are any signs of rotting or broken boards. When you install a metal roof over shingles, however, there is no way to determine the integrity of your roof’s decking.
This is crucial, because without inspecting the decking, there is no way to know if it’s in good enough condition to handle your new roof. Further, if there is a problem, then you won’t know about it until it becomes a larger, and more expensive, problem. And while your roof decking may be in great shape, it’s important to know that most roof replacements require some replacement decking, with some needing all new decking entirely.
An essential part of any roof replacement is ensuring that your roof decking is sturdy enough to handle a new roof. When installing a metal roof over shingles, however, there’s no chance to truly inspect the decking, which means you may have broken or rotting boards you can’t see. The problem here is that if you add a metal roof on top of an installed shingle roof, that adds a significant amount of weight that your decking has to support.
The takeaway here is that if your roof’s decking is compromised, the addition of this extra weight can cause structural damage to not just your roof, but also your home. Be aware, this won’t happen right away, unless your decking is in really bad shape, but will cause huge problems down the road. A reputable roofing contractor will never recommend installing a metal roof over shingles for this reason.
If you install a metal roof over shingles, you are also omitting the “tear-off process.” This process gives you the chance to replace old roofing components and materials that are either damaged or have reached the end of their lifespan. And while this may save you some up-front costs, it could end up costing you more down the road.
You don’t want to miss out on replacing important materials that should no longer be on your roof. A great example of this is underlayment, which is installed over your decking, protecting your roof’s foundation. When you install a metal roof over shingles, you have to rely on the existing underlayment that was originally installed.
This is a problem for a few reasons. First of all, underlayment is essentially your roof’s last line of defense, and roofing components aren’t meant to last forever. Second, you won’t get the proper underlayment installed that is designed specifically for metal roofs. Because of these reasons, we highly recommend a complete tear-off before any new roof installation.
Future Leaks and Repairs
When you install a metal roof over shingles, it becomes exponentially harder to find, follow, and fix roof leaks. If water makes its way under your metal roof, down to your old asphalt shingle roof, it will find the path of least resistance, and start leaking inside your home. The issue here is that the leak could be coming from one of two roofs.
This makes it tough for even the most experienced contractor to find the source of the leak. Plus, if the leak is coming from your old shingle roof, then your contractor will have to go through your new metal roof to fix it. Be sure to ask your roofer about the condition of your existing roof before you install a metal roof over it. If it already has roof leaks, you should avoid doing this altogether.
Addressing the Original Problem
Last on our list of reasons why you shouldn’t install a metal roof over shingles, is that by doing this, you are simply masking the issue. Any problems with your existing shingle roof will not go away by covering it with a metal roof. If your asphalt shingle roof has existing issues and is simply covered up, the problem will still be there when water finds its way under your new metal roof.
And even though you’ve covered up the existing roof, that doesn’t mean that the shingles and other components stop aging, either. Plus, if water keeps getting in between the old roof and the new roof, this can create mold and mildew, and rot your shingles over time. This is not only a health hazard, but could end up costing you more money in the long-term, as well.
Finding the Roof That’s Right for You
Now you know the five issues with putting a metal roof over shingles. And while these things may not happen to you, they are serious problems that should be considered. We highly recommend just choosing one roofing material; an asphalt roof, a metal roof, or something completely different.
And we know that choosing the roofing material that’s right for you can be a tedious process. It can also be stressful and overwhelming, as a new roof is an important investment, and you want to be sure you’re making the right choices. This is why we created the article, “4 Main Roofing Types [Pros, Cons, Costs, and More!],” so you can sort through your options and make informed decisions when it comes to your roofing needs.
Elite Exteriors is the Southeast’s premier residential and commercial resource for unparalleled service, superior craftsmanship and incomparable quality; and it’s all backed by an unprecedented lifetime labor and materials warranty. We would be honored to help you with your roofing needs, and to answer any questions you may have when it comes to your roof. Elite Exteriors also offers FREE initial consultations and inspections, and for more information, give us a call today at 470-350-3024, or fill out our online form.