As a professional metal roofing contractor, I often get a lot of questions about many different types of metal roofing systems and whether or not they would work in certain situations, of which the most mentioned problem is preventing ice dams. Interestingly, here in southern New England (Massachusetts, Rhode Island and Connecticut), we have a rather unique situation in regards to residential metal roofs. On one side, metal roofing is not very wide spread here and therefore most people are unaware of these excellent and permanent roofs. However, because of our close proximity to New Hampshire, Maine, and Vermont, many homeowners who consider a longer lasting roof than asphalt shingles, usually mention a metal roof that they’ve seen while “driving through New Hampshire”.
Because of this often-skewed perspective, most people that are aware of metal roofing, think that New Hampshire style vertical panels (standing seam) are the only type of metal roofs in existence, or are the best kind because that is what they’ve seen.
Despite this fairly prevalent belief about standing seam being “the only” or “the best” metal roofing system, this is just not true. I will mention that although standing seam metal roofs are very good, and time proven systems, they do, in fact, have a few negative aspects to them, which make them “not the best” for me personally. You can read my complete overview of why standing seam is an inferior metal roofing system at the end of this article.
Comparing different types of metal roofing systems:
Getting back to people’s general knowledge about metal roofing – there are many other metal roofing systems out there, which in some or most aspects are just as good or better than standing seam roofs. In this guide I am going to introduce you to some other popular systems, and compare the basic of product quality, system design, ease of installation, and price. Just to let you know, an ease of installation and system pricing are very inter-dependent, thus the more difficult it is to install a roofing system, the more you will have to pay for it.
So without further adieu, let me introduce our main contender (first one is standing seam, against which I will compare other metal roofs) – Interlocking Shingles. I will omit talking about other systems such as Metal Shakes, because they are very similar to metal shingles, and stone-coated steel roofs, because besides the good looks and the highly advertised strength of steel, and while they do work – they are rather poorly designed (my personal opinion as an installer).
Steel and aluminum interlocking shingles:
Interlocking metal shingle are just that – they have locks or hooks on all four sides. These locks hold the shingles together, preventing water and ice form penetrating the roof, while clips and nails hold the roof down to the deck. As an installer with over 10 years of experience, I can definitively say that an interlocking metal shingles roof is by far the most versatile residential metal roofing system in existence. It can be easily adjusted to and work with just about any normal roof penetration during the installation. The system can be easily installed on hips, valleys, side and end-walls. Flashing a skylight or a chimney with metal shingles system is a breeze, if not pleasure (Read the last section of this article, about flashing skylights with standing seam metal panels).
Most metal shingle systems that I know of, are VERY well designed, with some very durable 3/4″ locks on all sides, easy install sidewall and gable flashing, T-valleys, all with built-in water run-off channels that make the installation of metal shingle roofs fast, with an overall outstanding roof quality.
Metal shingles installation:
The pros & cons of Standing Seam:
First, the good: In many situations standing seam will be an excellent system that will last for decades, protecting your home or business from rain, snow, high winds, ice dams, etc. If your roof is simple gable, you can also expect a relatively reasonable price for your roof. If you have a walkable roof, the price may decrease a bit more.
The bad: If your roof gets complicated, you can expect to pay a lot for a standing seam roof, and even more for very steep roofs. The main reason for this is the way that a standing seam roof is designed and installed. Because of the vertical panel design, there is no way to put up any kind of roof brackets, so moving on such roof becomes extremely difficult and dangerous. While on a steep gable roof an installer can use a special hook ladder, thrown over the ridge, and move it left or right and he needs, working in valleys or even worse, on hip roofs, borders impossible, without a boom lift, except for roofs with low slope (3-4 in 12).
Another major limitation of standing seam is the inherited design flaws; The ribs on the panels make it a very difficult system to install, when it comes to any kind of flashing detail. For example it it is a wall flashing, the panel must be cut, making sure the cut is straight. Then a lip has to be bent up, and only then the panel can be attached to the roof. But this is not all. Now it is time for the Z-bar to be installed, and often then a side-wall or head-wall flashing. Mind you all of this must be done while the installer is on the roof, with all kinds of tools, and trying not to fall off the roof.
While all of the above is doable, and is done on regular basis, there is on type of flashing detail for which there isn’t a single good way to do it. I’m talking about chimneys and sky-lights. There are different ways to flash them, but all are reliant on caulking to make the watertight. The problem in in the back pan of every sky-light of chimney flashing (unless chimney has a cricket) and connection between back-pan and z-bar/sidewall flashing on the sides of the sky-light or a chimney.
I’ve included a link to one of the “best” ways to install such flashing detail, which for one, is very complicated, and I still would not use it. The problem is that there is no better way. Please review the sky-light / chimney flashing detail produced by ATAS. You may also read this thread on ContractorTalk regarding skylights in standing seam: http://www.contractortalk.com/f15/skylight-metal-roofing-60324/
So in a nutshell, standing seam is great when you have an easy roof. As soon as your roof gets complicated, you want to stay away from standing seam. If you still choose to use it, expect of of the following: A contractor you hire (I just don’t see a home owner installing a complicated standing seam roof) will charge a lot for a good installation. If you do get a “deal”, you can pretty much expect a somewhat frustrated contractor who is likely to be cutting every possible corner. If you hire an eager contractor, chances are it’s the their first complicated standing seam metal roof and you will probably get a mediocre quality at best, if the contractor actually manages to finish the roof. Some just stop in the middle of the installation and never come back to it, leaving you with a roof half-done.
Corrugated steel vs. standing seam:
Many people confuse standing seam with corrugated steel roof. Former one is an all concealed fasteners system, while the latter is an all exposed fasteners system. Also, corrugated steel roofs are usually (but not always) made of cheaper thin gauge (29 GA usually) steel painted with acrylic paint instead of 24 or 26 GA Galvalume or G-90 galvanized steel painted with Kynar 500 baked on coating consisting of 7 total layers of primer and paint. Kynar is actually a De-facto industry standard, when it comes to metal roof paints. Corrugated roofs are those that you can often see with rust spots all over and have a short life expectancy with high potential for leaks
Basically, unless you are absolutely in love with the looks of standing seam roofs, I strongly recommend getting an interlocking shingles metal roof – be it steel or aluminum. Price wise, you will get the same (if not better) performance for about 30-40% less money. You will also have a happy contractor, which is important for you in the first place, especially if your roof is rather complicated. You contractor won’t “hate” his life while working on your roof, and you will get a better installation quality (which is the most important part). In one sentence – you get a better product for less money – can’t beat that!