One of the biggest advantages of using metal roofs is that they are durable. Metal is more durable than any other roofing material used today.
It can withstand moist and humid climates like those in Northern Florida and can prove to be an excellent option when compared to regular shingles.
However, the biggest drawback if you can call it one is the fact that metal roofs are more expensive. One of the reasons why they are expensive is because of the high cost associated with installing them correctly.
Tearing off a traditional Shingle Roof and installing metal roofing isn’t easy, which is why it costs more. That’s why many home and business owners’ question if a metal roof can’t simply be installed over a regular shingle roof? In this article, we’ll go into detail to answer this question.
Can You Install a Metal Roof On Top Of A Traditional Shingle Roof?
The answer to this question isn’t as cut and dry as some people assume. Let’s say that your home has a traditional shingle roof, and now you want a metal roof because it’s more durable. So, the question is, do you need to tear off all the shingles first? The answer is “no”, you don’t need to tear all the shingles off the roof because metal roofing can be installed on top of them.
The biggest advantage of metal roofing is that even though metal is generally seen as being heavy, metal roofing is light. That’s why metal is the perfect material, especially for roofing on top of shingles. That said there are a few considerations worth making.
The most important being local building codes. Now before you have a roofing company pave over the shingles with a metal roof, you will want to check with the local building department to see if they approve of it. However, you shouldn’t have a problem with 60% of American municipalities.
Your Shingle Roof Should Be in Very Good Shape
Now, most building departments in every state will be happy to comply with the installation of metal roofing on top of regular shingle roofs, but there are safety caveats to consider. It is important for the Roofing Company to check and make sure that the plywood of the existing roof is in good enough shape.
There shouldn’t be any soft spots which later buckle under the weight.
While you might assume that the building department is trying to make your life harder, the fact is that safety is always a major concern. A metal roof is installed using screws and needs to be held on to something. If the plywood is soft and the screws can’t stay in because of it, then your roof could break. A thunderstorm or a bit of wind could blow the roof away.
Present Building Codes
Now, in Florida, there are some municipal building codes that have clearly stated that homeowners can’t have more than two layers of roofing. One reason for this was when the trusses of most homes were engineered; they could only hold on to a certain amount of weight.
If there are too many layers of Roofing Material, there is a good chance that the truss will fail. That’s why in some counties, it is imperative to remove all existing roofing material, regardless of the layer before a new roofing layer can be built.
By keeping the number of layers to a minimum, the building department can ensure that the plywood used is in the best condition and can hold up a roof. However, this does not apply to all counties, because in many others you can layer a metal roof on top of a traditional shingle roof.
But even then we’d advise that you get the roof examined by the roofing company to ensure that it can hold up to the stress of an additional layer.
Methods of Installing Metal Roofing On Top of Traditional Shingle Roof
Now two main methods are used to install metal roofing on top of shingle roofing. The first and perhaps the most common is to run a brand new underlayment on top of the shingle roof. The advantage of this is that it covers the old roof.
The new underlayment becomes a line of defence against water and erosion that may get through the metal roof. The other benefit of this approach is the fact that it works as a buffer between the shingle and metal roof.
Having a metal roof without a buffer will end up causing the shingle granules to slowly wear away against the roofing panes. If anything, it will shorten the life of your metal roof.
Now the second method usually involves installing the metal roof on top of the traditional shingle roof using battens and purlins. The purlins are screwed into the roof deck, and that depends on how the metal roofing brand has designed the panels to work.
The metal is then installed directly on to the purlins. The advantage of this method is that the installer has a flat surface to work on so the metal roofing panels can be installed without much in the way of grooves and irregularities.
As a homeowner, it is up to you to decide which method you want. However, it is essential to make sure that you are familiar with the pros and cons of each before proceeding.
A metal roof can very easily be installed over a traditional shingle roof, but it is essential to make sure that the plywood is in good condition. If not, then new plywood will need to be installed, and that will mainly mean re-roofing from the very beginning.
Always make sure that the metal roof is installed correctly because that’s the only way it can guarantee years of trouble-free service life. Plus, it will be able to protect your home and stay intact even during unusually bad weather which could otherwise blow away shingles and tiles.